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Malone CL, Rieger NS, Spool JA, Payette A, Riters LV, Marler CA. Behavioral convergence in defense behaviors in pair bonded individuals correlates with neuroendocrine receptors in the medial amygdala. Behav Brain Res 2023; 452:114556. [PMID: 37356669 PMCID: PMC10644349 DOI: 10.1016/j.bbr.2023.114556] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Revised: 06/19/2023] [Accepted: 06/22/2023] [Indexed: 06/27/2023]
Abstract
Monogamous, pair-bonded animals coordinate intra-pair behavior for spatially separated challenges including territorial defense and nest attendance. Paired California mice, a monogamous, territorial and biparental species, approach intruders together or separately, but often express behavioral convergence across intruder challenges. To gain a more systems-wide perspective of potential mechanisms contributing to behavioral convergence across two conspecific intruder challenges, we conducted an exploratory study correlating behavior and receptor mRNA (Days 10 and 17 post-pairing). We examined associations between convergence variability in pair time for intruder-oriented behaviors with a pair mRNA index for oxytocin (OXTR), androgen (AR), and estrogen alpha (ERα) receptors within the medial amygdala (MeA) and the anterior olfactory nucleus (AON), brain regions associated with social behavior. An intruder behavior index revealed a bimodal distribution of intruder-related behaviors in Challenge 1 and a unimodal distribution in Challenge 2, suggesting population behavioral convergence, but no significant correlations with neuroendocrine measures. However, OXTR, AR, and ERα mRNA in the MeA were positively associated with convergence in individual intruder-related behaviors, suggesting multiple mechanisms may influence convergence. Mice could also occupy the nest during intruder challenges and convergence in nest attendance was positively correlated with MeA OXTR. At an individual level, nest attendance was positively associated with MeA ERα. Vocalizations were positively associated with AR and ERα mRNA. No positive associations were found in the AON. Overall, neuroendocrine receptors were implicated in convergence of a monogamous pair's defense behavior, highlighting the potential importance of the MeA as part of a circuit underlying convergence.
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Affiliation(s)
- Candice L Malone
- University of Wisconsin-Madison, Department of Psychology, Madison, WI, USA.
| | - Nathaniel S Rieger
- University of Wisconsin-Madison, Department of Psychology, Madison, WI, USA; University of Washington-Seattle, Department of Psychiatry and Behavioral Sciences, Seattle, WA, USA
| | - Jeremy A Spool
- University of Wisconsin-Madison, Department of Integrative Biology, Madison, WI, USA; University of Massachusetts-Amherst, Department of Psychological and Brain Sciences, Amherst, MA, USA
| | - Alexis Payette
- University of Wisconsin-Madison, Department of Psychology, Madison, WI, USA
| | - Lauren V Riters
- University of Wisconsin-Madison, Department of Integrative Biology, Madison, WI, USA
| | - Catherine A Marler
- University of Wisconsin-Madison, Department of Psychology, Madison, WI, USA.
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2
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DeLacey PM, Sen S, Schneider-Crease IA, Chiou KL, Lemma A, Ayele F, Haile AA, Lu A, Bergman TJ, Beehner JC, Snyder-Mackler N. Vascularization underlies differences in sexually selected skin coloration in a wild primate. Mol Ecol 2023; 32:4401-4411. [PMID: 37226287 DOI: 10.1111/mec.17026] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Revised: 04/21/2023] [Accepted: 05/12/2023] [Indexed: 05/26/2023]
Abstract
Male reproductive competition can select for condition-dependent, conspicuous traits that signal some aspect of fighting ability and facilitate assessment of potential rivals. However, the underlying mechanisms that link the signal to a male's current condition are difficult to investigate in wild populations, often requiring invasive experimental manipulation. Here, we use digital photographs and chest skin samples to investigate the mechanisms of a visual signal used in male competition in a wild primate, the red chest patch in geladas (Theropithecus gelada). We analysed photographs collected during natural (n = 144) and anaesthetized conditions (n = 38) to understand variability in male and female chest redness, and we used chest skin biopsies (n = 38) to explore sex differences in gene expression. Male and female geladas showed similar average redness, but males exhibited a wider within-individual range in redness under natural conditions. These sex differences were also reflected at the molecular level, with 10.5% of genes exhibiting significant sex differences in expression. Subadult males exhibited intermediate gene expression patterns between adult males and females, pointing to mechanisms underlying the development of the red chest patch. We found that genes more highly expressed in males were associated with blood vessel development and maintenance but not with androgen or oestrogen activity. Together, our results suggest male gelada redness variability is driven by increased blood vessel branching in the chest skin, providing a potential link between male chest redness and current condition as increased blood circulation to exposed skin could lead to heat loss in the cold, high-altitude environment of geladas.
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Affiliation(s)
- Patricia M DeLacey
- Department of Psychology, University of Michigan, Ann Arbor, Michigan, USA
| | - Sharmi Sen
- Department of Anthropology, University of Michigan, Ann Arbor, Michigan, USA
| | - India A Schneider-Crease
- Center for Evolution and Medicine, Arizona State University, Tempe, Arizona, USA
- School of Life Sciences, Arizona State University, Tempe, Arizona, USA
- School of Human Evolution and Social Change, Arizona State University, Tempe, Arizona, USA
| | - Kenneth L Chiou
- Center for Evolution and Medicine, Arizona State University, Tempe, Arizona, USA
- School of Life Sciences, Arizona State University, Tempe, Arizona, USA
| | - Alemayehu Lemma
- College of Veterinary Medicine and Agriculture, Addis Ababa University, Ethiopia
| | - Ferehiwot Ayele
- College of Veterinary Medicine and Agriculture, Addis Ababa University, Ethiopia
| | | | - Amy Lu
- Department of Anthropology, Stony Brook University, New York, USA
| | - Thore J Bergman
- Department of Psychology, University of Michigan, Ann Arbor, Michigan, USA
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, Michigan, USA
| | - Jacinta C Beehner
- Department of Psychology, University of Michigan, Ann Arbor, Michigan, USA
- Department of Anthropology, University of Michigan, Ann Arbor, Michigan, USA
| | - Noah Snyder-Mackler
- Center for Evolution and Medicine, Arizona State University, Tempe, Arizona, USA
- School of Life Sciences, Arizona State University, Tempe, Arizona, USA
- School of Human Evolution and Social Change, Arizona State University, Tempe, Arizona, USA
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3
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Bezerra LGP, Silva AM, Jurema AP, Dantas MRT, Pereira AG, Oliveira MF, Comizzoli P, Silva AR. Changes in Sperm Morphology, Morphometry, and Motility from the Epididymis to the Vas Deferens in Rheas ( Rhea americana, Linnaeus, 1758). Animals (Basel) 2023; 13:ani13091483. [PMID: 37174520 PMCID: PMC10177575 DOI: 10.3390/ani13091483] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Revised: 04/22/2023] [Accepted: 04/25/2023] [Indexed: 05/15/2023] Open
Abstract
The objective was to characterize morphological, morphometric, and ultrastructural changes in rhea spermatozoa between the epididymis and the vas deferens. Sperm samples were collected from the reproductive tracts of seven adult individuals and evaluated for sperm characteristics using brightfield microscopy as well as ultrastructural features using scanning electron microscopy (SM). Mean sperm count tended to increase in the vas deferens (378.0 ± 135.0 × 106) compared to the epididymis (201.0 ± 77.4 × 106). Percentages of motile sperm grew from 37.0 ± 4.9% in the epididymis to 58.5 ± 7.7% in the vas deferens. The proportion of normal spermatozoa was 75.6 ± 1.8% and most common defects were bent tails (9.7 ± 0.9%). However, these proportions were not different between epididymis and vas deferens. SM analysis revealed further features of rhea spermatozoa. Normal rhea spermatozoa were threadlike with an acrosome (0.95 ± 0.0 µm), head (7.53 ± 0.01 µm), midpiece (2.08 ± 0.01 µm), and tail (30.7 ± 0.06 µm). Lengths of sperm acrosome, head, midpiece, and tail were longer in the vas deferens compared to the epididymis. Our findings suggest that rhea spermatozoa undergo a maturation process during the passage from the epididymis to the vas deferens.
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Affiliation(s)
- Luana G P Bezerra
- Laboratory of Animal Germplasm Conservation, Department of Animal Sciences, Universidade Federal Rural do Semi-Árido (UFERSA), Mossoró 59625-900, Brazil
| | - Andréia M Silva
- Laboratory of Animal Germplasm Conservation, Department of Animal Sciences, Universidade Federal Rural do Semi-Árido (UFERSA), Mossoró 59625-900, Brazil
| | - Artur P Jurema
- Laboratory of Animal Germplasm Conservation, Department of Animal Sciences, Universidade Federal Rural do Semi-Árido (UFERSA), Mossoró 59625-900, Brazil
| | - Maiko R T Dantas
- Laboratory of Animal Germplasm Conservation, Department of Animal Sciences, Universidade Federal Rural do Semi-Árido (UFERSA), Mossoró 59625-900, Brazil
| | - Ana G Pereira
- Laboratory of Animal Germplasm Conservation, Department of Animal Sciences, Universidade Federal Rural do Semi-Árido (UFERSA), Mossoró 59625-900, Brazil
| | - Moacir F Oliveira
- Laboratory of Animal Germplasm Conservation, Department of Animal Sciences, Universidade Federal Rural do Semi-Árido (UFERSA), Mossoró 59625-900, Brazil
| | - Pierre Comizzoli
- Smithsonian National Zoo and Conservation Biology Institute, Washington, DC 20008, USA
| | - Alexandre R Silva
- Laboratory of Animal Germplasm Conservation, Department of Animal Sciences, Universidade Federal Rural do Semi-Árido (UFERSA), Mossoró 59625-900, Brazil
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4
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Individual features influence the choice to attack in the southern lapwing Vanellus chilensis, but the opponent type dictates how the interaction goes. Acta Ethol 2023. [DOI: 10.1007/s10211-023-00416-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/13/2023]
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5
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Lilie ND, Riyahi S, Kalinowski A, Salazar SM, Kaiser S, Schmoll T, Korsten P. Male social niche conformance? Effects of manipulated opportunity for extra-pair mating on behavior and hormones of male zebra finches. Horm Behav 2022; 146:105243. [PMID: 35998552 DOI: 10.1016/j.yhbeh.2022.105243] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Revised: 07/21/2022] [Accepted: 08/04/2022] [Indexed: 11/17/2022]
Abstract
Success in sperm competition is an important determinant of male fitness in mating systems with female multiple mating. Thus, sperm competition risk represents a key dimension of the male social environment to which individual males are expected to adaptively adjust their reproductive phenotype. Such adaptive phenotypic adjustment we here refer to as male social niche conformance. In this pre-registered study, we investigated how male zebra finches, Taeniopygia guttata, adjust their behavior to sperm competition risk. We experimentally manipulated the opportunity for extra-pair mating to create two levels of sperm competition risk: 1) Single-pair, no sperm competition risk; 2) Double-pair, sperm competition risk. We compared male courtship, mate guarding, copulation rates, and aggression between the treatment groups. To identify hormonal correlates of male behavioral adjustment, we measured plasma testosterone and corticosterone levels before and after the social treatment started. Contrary to our pre-registered predictions, males from the Double-pair treatment group decreased courtship rates compared to those from the Single-pair group, and Double-pair males responded less aggressively towards intruders than Single-pair males. Testosterone levels decreased over the breeding cycle, but social treatment had no effect on either testosterone or corticosterone levels. Our results indicate that male zebra finches do not intensify courtship or competitive reproductive behaviors, or upregulate key hormones when another breeding pair is present. Although we found no evidence for the predicted adaptive behavioral responses to sperm competition risk, we show that male zebra finches plastically adjust their behavior to their social environment.
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Affiliation(s)
- Navina D Lilie
- Department of Animal Behaviour, Bielefeld University, Konsequenz 45, 33615 Bielefeld, Germany; Evolutionary Biology, Bielefeld University, Konsequenz 45, 33615 Bielefeld, Germany.
| | - Sepand Riyahi
- Department of Animal Behaviour, Bielefeld University, Konsequenz 45, 33615 Bielefeld, Germany; Evolutionary Biology, Bielefeld University, Konsequenz 45, 33615 Bielefeld, Germany
| | - Arne Kalinowski
- Department of Animal Behaviour, Bielefeld University, Konsequenz 45, 33615 Bielefeld, Germany
| | - Stephen M Salazar
- Department of Animal Behaviour, Bielefeld University, Konsequenz 45, 33615 Bielefeld, Germany; Behavioural & Physiological Ecology, Groningen Institute for Evolutionary Life Sciences, University of Groningen, Nijenborgh 7, 9747 AG Groningen, the Netherlands
| | - Sylvia Kaiser
- Department of Behavioural Biology, University of Münster, Badestraße 13, 48149 Münster, Germany
| | - Tim Schmoll
- Evolutionary Biology, Bielefeld University, Konsequenz 45, 33615 Bielefeld, Germany
| | - Peter Korsten
- Department of Animal Behaviour, Bielefeld University, Konsequenz 45, 33615 Bielefeld, Germany.
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6
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Crino OL, Falk S, Katsis AC, Kraft FLOH, Buchanan KL. Mitochondria as the powerhouses of sexual selection: Testing mechanistic links between development, cellular respiration, and bird song. Horm Behav 2022; 142:105184. [PMID: 35596967 DOI: 10.1016/j.yhbeh.2022.105184] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Revised: 04/21/2022] [Accepted: 04/22/2022] [Indexed: 11/04/2022]
Abstract
The developmental environment can affect the expression of sexually selected traits in adulthood. The physiological mechanisms that modulate such effects remain a matter of intense debate. Here, we test the role of the developmental environment in shaping adult mitochondrial function and link mitochondrial function to expression of a sexually selected trait in males (bird song). We exposed male zebra finches (Taeniopygia guttata) to corticosterone (CORT) treatment during development. After males reached adulthood, we quantified mitochondrial function from whole red blood cells and measured baseline CORT and testosterone levels, body condition/composition, and song structure. CORT-treated males had mitochondria that were less efficient (FCRL/R) and used a lower proportion of maximum capacity (FCRR/ETS) than control males. Additionally, CORT-treated males had higher baseline levels of CORT as adults compared to control males. Using structural equation modelling, we found that the effects of CORT treatment during development on adult mitochondrial function were indirect and modulated by baseline CORT levels, which are programmed by CORT treatment during development. Developmental treatment also had an indirect effect on song peak frequency. Males treated with CORT during development sang songs with higher peak frequency than control males, but this effect was modulated through increased CORT levels and by a decrease in FCRR/ETS. CORT-treated males had smaller tarsi compared to control males; however, there were no associations between body size and measures of song frequency. Here, we provide the first evidence supporting links between the developmental environment, mitochondrial function, and the expression of a sexually selected trait (bird song).
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Affiliation(s)
- Ondi L Crino
- Research School of Biology, Australian National University, Canberra, ACT, Australia; Centre for Integrative Ecology, School of Life and Environmental Sciences, Deakin University, Geelong, Victoria, Australia.
| | - Steph Falk
- School of Biological Science Monash University, Melbourne, VIC, Australia; Institute of Immunology and Epigenetics, Max Planck Institute, Baden-Württemberg, Germany
| | - Andrew C Katsis
- Centre for Integrative Ecology, School of Life and Environmental Sciences, Deakin University, Geelong, Victoria, Australia; College of Science and Engineering, Flinders University, Adelaide, SA, Australia
| | - Fanny-Linn O H Kraft
- Centre for Integrative Ecology, School of Life and Environmental Sciences, Deakin University, Geelong, Victoria, Australia; Department of Zoology, Stockholm University, Stockholm, Sweden
| | - Katherine L Buchanan
- Centre for Integrative Ecology, School of Life and Environmental Sciences, Deakin University, Geelong, Victoria, Australia
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7
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Schuppe ER, Tobiansky D, Goller F, Fuxjager MJ. Specialized androgen synthesis in skeletal muscles that actuate elaborate social displays. J Exp Biol 2022; 225:275472. [PMID: 35587151 DOI: 10.1242/jeb.243730] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Accepted: 05/12/2022] [Indexed: 11/20/2022]
Abstract
Androgens mediate the expression of many reproductive behaviors, including the elaborate displays used to navigate courtship and territorial interactions. In some vertebrates, males can produce androgen-dependent sexual behavior even when levels of testosterone (T) is low in the bloodstream. One idea is that select tissues make their own androgens from scratch to support behavioral performance. We first study this phenomenon in the skeletal muscles that actuate elaborate sociosexual displays in downy woodpeckers and two songbirds. We show that the woodpecker display muscle maintains elevated T when the testes are regressed in the non-breeding season. Both the display muscles of woodpeckers, as well as the display muscles in the avian vocal organ (syrinx or SYR) of songbirds, express all transporters and enzymes necessary to convert cholesterol into bioactive androgens locally. In a final analysis, we broaden our study by looking for these same transporters and enzymes in mammalian muscles that operate at different speeds. Using RNA-seq data, we find that the capacity for de novo synthesis is only present in "superfast" extraocular muscle. Together, our results suggest that skeletal muscle specialized to generate extraordinary twitch-times and/or extremely rapid contractile speeds may depend on androgenic hormones produced locally within the muscle itself. Our study therefore uncovers an important new dimension of androgenic regulation of behavior.
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Affiliation(s)
- Eric R Schuppe
- Department of Neurobiology and Behavior, Cornell University, 215 Tower Road, Ithaca, NY 14850, USA
| | - Daniel Tobiansky
- Department of Ecology, Evolution, and Organismal Biology, Brown University, 171 Meeting Street, Providence, RI 02912, USA
| | - Franz Goller
- Department of Biology, University of Utah, USA.,Institute for Zoophysiology, University of Münster, Germany
| | - Matthew J Fuxjager
- Department of Ecology, Evolution, and Organismal Biology, Brown University, 171 Meeting Street, Providence, RI 02912, USA
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8
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Lopes LE, Teixeira JPG, Meireles RC, Bastos DSS, de Oliveira LL, Solar R. High Seasonal Variation of Plasma Testosterone Levels for a Tropical Grassland Bird Resembles Patterns of Temperate Birds. Physiol Biochem Zool 2021; 94:143-151. [PMID: 33705275 DOI: 10.1086/713503] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
AbstractTestosterone (T) is a sexual hormone capable of modulating several traits in birds, including aggressiveness and reproductive behavior. Although variation in T-related traits is well-known for temperate zone birds, this variation has not been extensively studied in tropical species. The campo miner (Geositta poeciloptera) is a threatened bird endemic to the grasslands of the South American Cerrado. We investigated the seasonal variation in plasma T levels and associated behavior in the campo miner, addressing the following questions: (1) Does the species exhibit seasonal variation in T profile? (2) Do males have higher plasma T levels than females, irrespective of season? (3) Are males with higher plasma T levels more aggressive than males with lower T levels? (4) Do males' plasma T levels decrease after females lay eggs? We found that T levels are higher during the breeding season than during the nonbreeding season and that males present higher T levels than females throughout the year. Such high T levels are associated with a higher probability to engage in aggressive behavior; however, T levels decline toward the egg-laying date and keep decreasing afterward. Higher T levels before egg laying are apparently related to territorial defense against invaders and extrapair copulations. With the beginning of parental care, T levels decrease, which is in line with previous observations that the species becomes less aggressive after egg laying. This study contributes to the understanding of environmental endocrinology of tropical birds, filling some knowledge gaps about the diverse Neotropical avifauna.
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9
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Prado-Ortiz LE, Valdespino C, Romano M, González-Romero A. Quantification of immunoreactive testosterone and estradiol-17ß metabolites to identify the sex of Neotropical otters (Lontra longicaudis annectens) in the field. Anim Reprod Sci 2020; 222:106607. [PMID: 33017800 DOI: 10.1016/j.anireprosci.2020.106607] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Revised: 09/14/2020] [Accepted: 09/15/2020] [Indexed: 01/24/2023]
Abstract
Before there was use of ultrasonographic imaging, determination of the ratio of estrogens to androgens in the same individual was a technique used for differentiating the sex of monomorphic animals in captivity, with larger estrogen concentrations in the females. Due to species-specific differences in both concentration and changes throughout the year of these hormones, corroboration of the method is needed in each case. In this study, there was use of a chemo-immuno assay to quantify sex steroids in fecal samples collected from seven (five females and two males) Neotropical otters, Lontra longicaudis. The reproductive season for this species was determined to be between October and March, with increased estradiol in the females and relatively greater concentrations of testosterone in the males as compared with other seasons of the year. Results from utilization of a k-means analysis procedure indicated that the use of steroid ratios in fecal samples to differentiate otter sex is an effective technique when there are evaluations during the breeding season. The estrogen to androgen ratios during this period, however, are the inverse of what was expected, with there being larger testosterone concentrations in the female otters. The ratio of estrogens to androgens in feces of captive otters can be effectively used to determine the sex of otters in the field. We propose this method is reliable for sex determination in wild otter populations during the reproductive season.
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Affiliation(s)
- L E Prado-Ortiz
- Red de Biología y Conservación de Vertebrados, Instituto de Ecología A. C., Carretera Antigua a Coatepec # 351, El haya, 91070 Xalapa, Veracruz, Mexico
| | - C Valdespino
- Red de Biología y Conservación de Vertebrados, Instituto de Ecología A. C., Carretera Antigua a Coatepec # 351, El haya, 91070 Xalapa, Veracruz, Mexico.
| | - M Romano
- D. Fisiología, Biofísica y Neurociencias, CINVESTAV, Mexico
| | - A González-Romero
- Red de Biología y Conservación de Vertebrados, Instituto de Ecología A. C., Carretera Antigua a Coatepec # 351, El haya, 91070 Xalapa, Veracruz, Mexico
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10
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Kirschel AN, Zanti Z, Harlow ZT, Vallejo EE, Cody ML, Taylor CE. Females don't always sing in response to male song, but when they do, they sing to males with higher-pitched songs. Anim Behav 2020. [DOI: 10.1016/j.anbehav.2020.06.024] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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11
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Rendon NM, Petersen CL, Munley KM, Amez AC, Boyes DL, Kingsbury MA, Demas GE. Seasonal patterns of melatonin alter aggressive phenotypes of female Siberian hamsters. J Neuroendocrinol 2020; 32:e12894. [PMID: 32808694 DOI: 10.1111/jne.12894] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Revised: 06/19/2020] [Accepted: 07/15/2020] [Indexed: 12/16/2022]
Abstract
Many animal species exhibit year-round aggression, a behaviour that allows individuals to compete for limited resources in their environment (eg, food and mates). Interestingly, this high degree of territoriality persists during the non-breeding season, despite low levels of circulating gonadal steroids (ie, testosterone [T] and oestradiol [E2 ]). Our previous work suggests that the pineal hormone melatonin mediates a 'seasonal switch' from gonadal to adrenal regulation of aggression in Siberian hamsters (Phodopus sungorus); solitary, seasonally breeding mammals that display increased aggression during the short, 'winter-like' days (SDs) of the non-breeding season. To test the hypothesis that melatonin elevates non-breeding aggression by increasing circulating and neural steroid metabolism, we housed female hamsters in long days (LDs) or SDs, administered them timed or mis-timed melatonin injections (mimic or do not mimic a SD-like signal, respectively), and measured aggression, circulating hormone profiles and aromatase (ARO) immunoreactivity in brain regions associated with aggressive or reproductive behaviours (paraventricular hypothalamic nucleus [PVN], periaqueductal gray [PAG] and ventral tegmental area [VTA]). Females that were responsive to SD photoperiods (SD-R) and LD females given timed melatonin injections (Mel-T) exhibited gonadal regression and reduced circulating E2 , but increased aggression and circulating dehydroepiandrosterone (DHEA). Furthermore, aggressive challenges differentially altered circulating hormone profiles across seasonal phenotypes; reproductively inactive females (ie, SD-R and Mel-T females) reduced circulating DHEA and T, but increased E2 after an aggressive interaction, whereas reproductively active females (ie, LD females, SD non-responder females and LD females given mis-timed melatonin injections) solely increased circulating E2 . Although no differences in neural ARO abundance were observed, LD and SD-R females showed distinct associations between ARO cell density and aggressive behaviour in the PVN, PAG and VTA. Taken together, these results suggest that melatonin increases non-breeding aggression by elevating circulating steroid metabolism after an aggressive encounter and by regulating behaviourally relevant neural circuits in a region-specific manner.
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Affiliation(s)
- Nikki M Rendon
- Department of Biology and Center for the Integrative Study of Animal Behavior, Indiana University, Bloomington, IN, USA
| | | | - Kathleen M Munley
- Department of Biology and Center for the Integrative Study of Animal Behavior, Indiana University, Bloomington, IN, USA
| | - Andrea C Amez
- Department of Biology and Center for the Integrative Study of Animal Behavior, Indiana University, Bloomington, IN, USA
| | - Daniel L Boyes
- Department of Biology and Center for the Integrative Study of Animal Behavior, Indiana University, Bloomington, IN, USA
| | - Marcy A Kingsbury
- Department of Pediatrics, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Gregory E Demas
- Department of Biology and Center for the Integrative Study of Animal Behavior, Indiana University, Bloomington, IN, USA
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12
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Yan Z, Isobe N, Kawakami SI. Effects of Testicular and Non-Testicular Testosterone on Territorial and Isolation-induced Aggressive Behavior of Male Layer Chicks. J Poult Sci 2020; 57:236-240. [PMID: 32733158 PMCID: PMC7387941 DOI: 10.2141/jpsa.0190109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2019] [Accepted: 10/15/2019] [Indexed: 12/01/2022] Open
Abstract
Testosterone (T) is known to induce aggressive behavior, particularly in male animals. However, our recent results showed that a certain kind of aggressive behavior is T-independent; moreover, the role of T in chicken territorial and isolation-induced aggressive behavior has not yet been investigated. In addition, castration alone is insufficient to evaluate the role of T in aggressive behavior because we found that non-testicular T concentration, probably derived from the adrenal gland, in the blood of castrated chicks was low, but not zero. In the present study, therefore, the role of testicular T in chicken aggressive behavior was evaluated through castration, and the role of nontesticular T was assessed using the subcutaneous implantation of flutamide, a non-steroidal antiandrogen, in the castrated male layer chicks. Resident-intruder (R-I) and social interaction (SI) tests were used to quantitatively monitor territorial and isolation-induced aggressive behavior, respectively. Castration and drug implantation of the chicks were performed at 14 days of age. The R-I test was performed at 29 and 30 days of age, and the SI test was performed at 31 and 32 days of age. The total aggression frequencies (TAFs) and aggression establishment rate (AER) were used as indices of chick aggressive behavior. In the R-I test, castration significantly decreased the TAFs but the AER was not affected by castration or flutamide implantation. In the SI test, on the other hand, there were no significant differences in the TAFs, but the AER tended to increase in the intact chicks and decrease in the flutamide-implanted, castrated male chicks. These results suggest that the role of T in chicken aggression depends on the differences in social context of the behavior, and that both testicular and non-testicular T play an important role in the occurrence of isolation-induced aggression in male layer chicks.
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Affiliation(s)
- Zhiqun Yan
- Graduate School of Integrated Sciences for Life, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8528, Japan
| | - Naoki Isobe
- Graduate School of Integrated Sciences for Life, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8528, Japan
- The Research Center for Animal Science, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8528, Japan
| | - Shin-Ichi Kawakami
- Graduate School of Integrated Sciences for Life, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8528, Japan
- Japanese Avian Bioresource Project Research Center, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8528, Japan
- The Research Center for Animal Science, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8528, Japan
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13
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Schuppe ER, Fuxjager MJ. Phenotypic variation reveals sites of evolutionary constraint in the androgenic signaling pathway. Horm Behav 2019; 115:104538. [PMID: 31211944 DOI: 10.1016/j.yhbeh.2019.06.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Revised: 05/19/2019] [Accepted: 06/10/2019] [Indexed: 01/05/2023]
Abstract
Steroid hormone systems play an important role in shaping the evolution of vertebrate sexual traits, but several aspects of this relationship remain unclear. For example, we currently know little about how steroid signaling complexes are adapted to accommodate the emergence of behavior in response to sexual selection. We use downy woodpeckers (Dryobates pubescens) to evaluate how the machinery underlying androgen action can evolve to accommodate this bird's main territorial signal, the drum. We focus specifically on modifications to androgenic mechanisms in the primary neck muscle that actuates the hammering movements underlying this signal. Of the signaling components we examine, we find that levels of circulating testosterone (T) and androgen receptor (AR) expression are consistently increased in a way that likely enhances androgenic regulation of drumming. By contrast, the expression of nuclear receptor co-factors-the 'molecular rheostats' of steroid action-show no such relationship in our analyses. If anything, co-factors are expressed in directions that would presumably hinder androgenic regulation of the drum. These findings therefore collectively point to T levels and AR as the more evolutionarily labile components of the androgenic system, in that they are likely more apt to change over time to support sexual selection for territorial signaling in woodpeckers. Yet the signaling elements that fine-tune AR's functional effects on the genome-namely the receptor's transcriptional co-factors-do not change in such a manner, and thus may be under tighter evolutionary constraint.
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Affiliation(s)
- Eric R Schuppe
- Department of Biology, Wake Forest University, 455 Vine Street, Winston-Salem, NC 27101, United States of America
| | - Matthew J Fuxjager
- Department of Ecology and Evolutionary Biology, Brown University, Providence, RI 02912, United States of America.
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14
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Weissman YA, Demartsev V, Ilany A, Barocas A, Bar-Ziv E, Geffen E, Koren L. Social context mediates testosterone's effect on snort acoustics in male hyrax songs. Horm Behav 2019; 114:104535. [PMID: 31129283 DOI: 10.1016/j.yhbeh.2019.05.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/14/2018] [Revised: 03/25/2019] [Accepted: 05/18/2019] [Indexed: 11/20/2022]
Abstract
Testosterone affects physical and motivational states, both of which may strongly influence vocalization structure and acoustics. The loud complex calls (i.e., songs) of male rock hyraxes (Procavia capensis) are used as honest signals for advertising physical and social states. The snort, a low frequency, noisy element of the song, encodes information on the singer's age and social rank via harshness, as measured by jitter (i.e., acoustic frequency stability) and duration; suggesting that the snort concomitantly advertises both vocal stability and aggression. Our past findings revealed that testosterone levels are related to both vocal elements and social status of male hyraxes, suggesting that hormonal mechanisms mediate the motivation for aggressive and courtship behaviors. Here we examined whether long-term androgen levels are related to snort acoustics and song structure by comparing levels of testosterone in hair with acoustic and structural parameters. We found that songs performed by individuals with higher testosterone levels include more singing bouts and longer, smoother snorts, but only in those songs induced by external triggers. It is possible that hyraxes with higher levels of testosterone possess the ability to perform higher-quality singing, but only invest in situations of high social arousal and potential benefit. Surprisingly, in spontaneous songs, hyraxes with high testosterone were found to snort more harshly than low-testosterone males. The context dependent effects of high testosterone on snort acoustics suggest that the aggressive emotional arousal associated with testosterone is naturally reflected in the jittery hyrax snort, but that it can be masked by high-quality performance.
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Affiliation(s)
- Yishai A Weissman
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan 52900, Israel
| | - Vlad Demartsev
- School of Zoology, Tel Aviv University, Tel Aviv 69978, Israel
| | - Amiyaal Ilany
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan 52900, Israel
| | - Adi Barocas
- San Diego Zoo's Institute for Conservation Research, Escondido, CA 92027, USA; Wildlife Conservation Research Unit, Department of Zoology, University of Oxford, Oxford, UK
| | - Einat Bar-Ziv
- School of Zoology, Tel Aviv University, Tel Aviv 69978, Israel; Mitrani Dept. of Desert Ecology, Ben-Gurion University of the Negev, 8499000, Israel
| | - Eli Geffen
- School of Zoology, Tel Aviv University, Tel Aviv 69978, Israel
| | - Lee Koren
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan 52900, Israel.
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15
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Heller EL, Gaff HD, Brinkerhoff RJ, Walters EL. Urbanization and tick parasitism in birds of coastal southeastern Virginia. J Wildl Manage 2019. [DOI: 10.1002/jwmg.21646] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Erin L. Heller
- Department of Biological SciencesOld Dominion UniversityNorfolkVA23529USA
| | - Holly D. Gaff
- Department of Biological SciencesOld Dominion UniversityNorfolkVA23529USA
| | | | - Eric L. Walters
- Department of Biological SciencesOld Dominion UniversityNorfolkVA23529USA
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16
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Lorena J, Olson CR, Fontana CS, Mello CV, Schneider MPC, Schneider PN. Seasonal changes in the song control nuclei of the Rufous-bellied Thrush, Turdus rufiventris (Oscine, Passeriformes, and Turdidae). JOURNAL OF EXPERIMENTAL ZOOLOGY PART B-MOLECULAR AND DEVELOPMENTAL EVOLUTION 2019; 332:92-98. [PMID: 31004403 DOI: 10.1002/jez.b.22853] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Revised: 02/25/2019] [Accepted: 03/20/2019] [Indexed: 11/11/2022]
Abstract
In vocal learning birds, memorization and song production rely on a set of telencephalic nuclei referred to as the song control system. Seasonal changes in song production are correlated with changes in the volume of the song control nuclei and are influenced by photoperiodic conditions and hormonal cues. The seasonal volume changes in the avian brain that controls singing are thought to involve regulation of neuronal replacement, which is a striking example of neuronal plasticity. The Rufous-bellied Thrush (Turdus rufiventris) is a seasonally breeding bird that actively sings during the spring and summer (breeding season) and is relatively silent in the fall, yet possible mechanisms behind the periodic changes in song production remain unknown. Here, we have examined two song control nuclei: High vocal center (HVC) and robust nucleus of arcopallium (RA) in fall males, spring males, and fall females of Rufous-bellied Thrush. The cytoarchitectonic organization was analyzed and quantified from Nissl-stained sections, and gene expression of song nuclei markers was examined by in situ hybridization during breeding and nonbreeding seasons. We observed a reduction in HVC volume and reductions in parvalbumin, and RGS4 expression in HVC and RA in males during the nonbreeding season. These findings provide evidence of seasonal changes in the song system of a representative tropical-breeding Turdidae species that does not maintain territories or mate bonding, setting the histological and molecular groundwork for future studies aimed at better understanding of song nuclei changes in seasonally breeding songbirds.
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Affiliation(s)
- Jamily Lorena
- Instituto de Ciências Biológicas, Centro de Genômica e Biologia de Sistemas, Universidade Federal do Pará, Belém, Brazil
| | | | - Carla S Fontana
- Museu de Ciência e Tecnologia, Laboratório de Ornitologia, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, Brazil
| | - Claudio V Mello
- Department of Behavioral Neuroscience, Oregon Health & Science University, Portland, Oregon
| | - Maria Paula C Schneider
- Instituto de Ciências Biológicas, Centro de Genômica e Biologia de Sistemas, Universidade Federal do Pará, Belém, Brazil
| | - Patricia N Schneider
- Instituto de Ciências Biológicas, Centro de Genômica e Biologia de Sistemas, Universidade Federal do Pará, Belém, Brazil
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17
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Hunt KE, Hahn TP, Buck CL, Wingfield JC. Effect of testosterone blockers on male aggression, song and parental care in an arctic passerine, the Lapland longspur (Calcarius lapponicus). Horm Behav 2019; 110:10-18. [PMID: 30735664 DOI: 10.1016/j.yhbeh.2019.02.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/18/2018] [Revised: 01/16/2019] [Accepted: 02/04/2019] [Indexed: 01/19/2023]
Abstract
In many passerine birds, testosterone stimulates song and aggression but inhibits paternal care, but few studies have explored whether such effects can be reversed with testosterone blockers. We explored the effect of testosterone blockers on song, aggression and paternal care of Lapland longspurs (Calcarius lapponicus), an arctic passerine with a short breeding season. Twenty-one "blocker males" received implants containing an androgen receptor blocker and an aromatase inhibitor, compared to 27 control males with empty or no implants. Song, aggression and other behaviors were evaluated with simulated territorial intrusions (STI) during mate-guarding, and with focal observations (without STI) during mate-guarding and incubation. Nests were monitored and nestlings weighed as an indirect measure of paternal care. During STI, blocker males exhibited similar song rates, significantly lower aggression, and were significantly less likely to be found on territory than control males. Focal observations revealed no differences in spontaneous song, aggression, foraging, preening, or flight activity. Blocker males' nestlings had greater body mass on day 5 after hatching, but this difference disappeared by fledging, and both groups fledged similar numbers of young. Two blocker males exhibited unusual paternal care: incubation and brooding of young, or feeding of nestlings at another male's nest. In sum, testosterone blockers affected aggression but not song, contrasting with results from previously published testosterone implant studies. Effects on paternal care were concordant with testosterone implant studies. These patterns may be related to rapid behavioral changes characteristic of the short breeding season of the Arctic.
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Affiliation(s)
- Kathleen E Hunt
- Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ 86011, USA.
| | - Thomas P Hahn
- Department of Neurobiology, Physiology & Behavior, University of California, One Shields Ave., Davis, CA 95616, USA.
| | - C Loren Buck
- Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ 86011, USA.
| | - John C Wingfield
- Department of Neurobiology, Physiology & Behavior, University of California, One Shields Ave., Davis, CA 95616, USA.
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18
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Moore IT, Vernasco BJ, Escallón C, Small TW, Ryder TB, Horton BM. Tales of testosterone: Advancing our understanding of environmental endocrinology through studies of neotropical birds. Gen Comp Endocrinol 2019; 273:184-191. [PMID: 29990493 DOI: 10.1016/j.ygcen.2018.07.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Revised: 06/21/2018] [Accepted: 07/06/2018] [Indexed: 01/29/2023]
Abstract
Studies of birds have greatly advanced our understanding of how testosterone modulates complex phenotypes, specifically its role in mediating male reproductive and associated behaviors. Yet most of the foundational studies have been limited to northern latitude breeding species despite the fact that they represent only a small fraction of worldwide avian diversity. In contrast, phylogenetic, life-history, and mating system diversity all reach their apex in neotropical avifauna and yet these birds, along with more southern latitude species, remain very poorly understood from an endocrine perspective. Despite the relatively limited previous work on taxa breeding in Central and South America, empirical findings have had a disproportionately large impact on our understanding of testosterone's role in everything from geographic variation to behavioral roles and neuroplasticity. Here, we synthesize how studies of neotropical breeding avifauna have advanced our understanding of how testosterone's actions can and are associated with the broad patterns of phenotypic diversity that we see in birds. In addition, we outline how these studies can be used individually or in a comparative context to address fundamental questions about the environmental endocrinology of testosterone and to understand the diversity of roles that testosterone plays in mediating behavioral variation, reproductive strategies, and associated life-history trade-offs.
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Affiliation(s)
- I T Moore
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA 24061, USA.
| | - B J Vernasco
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA 24061, USA
| | - C Escallón
- Departamento de Ciencias Básicas, Universidad de la Salle, Cra 2 No. 10-70, Bogotá, Colombia
| | - T W Small
- Department of Biology, University of Memphis, Memphis, TN 38152, USA
| | - T B Ryder
- Migratory Bird Center, Smithsonian Conservation Biology Institute, National Zoological Park, PO Box 37012, MRC 5503, Washington DC 20013, USA
| | - B M Horton
- Department of Biology, Millersville University of Pennsylvania, Millersville, PA 17551, USA
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19
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Non-breeding territoriality and the effect of territory size on aggression in the weakly electric fish, Gymnotus omarorum. Acta Ethol 2019. [DOI: 10.1007/s10211-019-00309-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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20
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Tecot SR, Baden AL. Profiling caregivers: Hormonal variation underlying allomaternal care in wild red-bellied lemurs, Eulemur rubriventer. Physiol Behav 2018; 193:135-148. [DOI: 10.1016/j.physbeh.2017.12.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2017] [Revised: 12/05/2017] [Accepted: 12/05/2017] [Indexed: 01/31/2023]
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21
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Shevchouk OT, Ghorbanpoor S, Smith E, Liere P, Schumacher M, Ball GF, Cornil CA, Balthazart J. Behavioral evidence for sex steroids hypersensitivity in castrated male canaries. Horm Behav 2018; 103:80-96. [PMID: 29909262 DOI: 10.1016/j.yhbeh.2018.06.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Revised: 06/05/2018] [Accepted: 06/10/2018] [Indexed: 12/30/2022]
Abstract
In seasonally breeding songbirds such as canaries, singing behavior is predominantly under the control of testosterone and its metabolites. Short daylengths in the fall that break photorefractoriness are followed by increasing daylengths in spring that activate singing via both photoperiodic and hormonal mechanisms. However, we observed in a group of castrated male Fife fancy canaries maintained for a long duration under a short day photoperiod a large proportion of subjects that sang at high rates. This singing rate was not correlated with variation in the low circulating concentrations of testosterone. Treatment of these actively singing castrated male canaries with a combination of an aromatase inhibitor (ATD) and an androgen receptor blocker (flutamide) only marginally decreased this singing activity as compared to control untreated birds and did not affect various measures of song quality. The volumes of HVC and of the medial preoptic nucleus (POM) were also unaffected by these treatments but were relatively large and similar to volumes in testosterone-treated males. In contrast, peripheral androgen-sensitive structures such as the cloacal protuberance and syrinx mass were small, similar to what is observed in castrates. Together these data suggest that after a long-term steroid deprivation singing behavior can be activated by very low concentrations of testosterone. Singing normally depends on the activation by testosterone and its metabolites of multiple downstream neurochemical systems such as catecholamines, nonapeptides or opioids. These transmitter systems might become hypersensitive to steroid action after long term castration as they probably are at the end of winter during the annual cycle in seasonally breeding temperate zone species.
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Affiliation(s)
| | | | - Ed Smith
- Department of Psychology, University of Maryland, College Park, MD 20742, United States of America
| | - Philippe Liere
- INSERM UMR 1195 and Université Paris Sud and University Paris-Saclay, Le Kremlin-Bicêtre Cedex, France
| | - Michael Schumacher
- INSERM UMR 1195 and Université Paris Sud and University Paris-Saclay, Le Kremlin-Bicêtre Cedex, France
| | - Gregory F Ball
- Department of Psychology, University of Maryland, College Park, MD 20742, United States of America
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22
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Berzins LL, Shrimpton JM, Dawson RD. Experimentally altering pre-breeding sex steroids reduces extra-pair paternity in female tree swallows. Ethology 2018. [DOI: 10.1111/eth.12745] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Lisha L. Berzins
- Ecosystem Science and Management Program; University of Northern British Columbia; Prince George BC Canada
| | - J. Mark Shrimpton
- Ecosystem Science and Management Program; University of Northern British Columbia; Prince George BC Canada
| | - Russell D. Dawson
- Ecosystem Science and Management Program; University of Northern British Columbia; Prince George BC Canada
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23
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Funghi C, Trigo S, Gomes ACR, Soares MC, Cardoso GC. Release from ecological constraint erases sex difference in social ornamentation. Behav Ecol Sociobiol 2018. [DOI: 10.1007/s00265-018-2486-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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24
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Davies S, Beck ML, Sewall KB. Territorial aggression in urban and rural Song Sparrows is correlated with corticosterone, but not testosterone. Horm Behav 2018; 98:8-15. [PMID: 29166572 DOI: 10.1016/j.yhbeh.2017.11.010] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/01/2017] [Revised: 11/06/2017] [Accepted: 11/17/2017] [Indexed: 02/09/2023]
Abstract
Urban songbirds of several species more vigorously defend their territories in response to conspecific song playback than do their rural counterparts, but the hormonal basis of this behavioral difference is unclear. It is well established in vertebrates that both testosterone and corticosterone affect the intensity of territoriality. Previous studies have found no evidence that initial (i.e., immediately following territorial challenge, but prior to restraint) plasma testosterone accounts for the elevated territorial aggression of urban birds. Determining if testosterone still contributes to urban-rural differences in territoriality requires also assessing males' abilities to transiently increase plasma testosterone (in response to an injection of gonadotropin-releasing hormone). We tested whether these hormones are correlated with the territorial response to conspecific song playback in urban and rural male Song Sparrows (Melospiza melodia) in Montgomery County, Virginia. We found that the elevated territorial aggression of urban sparrows was not related to variation in either initial plasma testosterone or the ability to transiently increase testosterone. In contrast, despite no overall habitat difference in initial corticosterone, levels of this hormone were positively correlated with territoriality in urban and rural sparrows. Furthermore, for a given level of corticosterone, urban sparrows were more territorially aggressive. Our findings suggest that initial corticosterone may either play a role in the regulation of persistent differences in territorial behavior between free-ranging urban and rural male Song Sparrows or be affected by the intensity of behavioral response to territorial challenge.
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Affiliation(s)
- Scott Davies
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA 24061, USA.
| | - Michelle L Beck
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA 24061, USA
| | - Kendra B Sewall
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA 24061, USA
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25
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Pikus AE, Guindre-Parker S, Rubenstein DR. Testosterone, social status and parental care in a cooperatively breeding bird. Horm Behav 2018; 97:85-93. [PMID: 29054796 DOI: 10.1016/j.yhbeh.2017.10.008] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/09/2017] [Revised: 10/14/2017] [Accepted: 10/16/2017] [Indexed: 01/14/2023]
Abstract
The steroid hormone testosterone not only plays an important role in gamete production, but also influences social and aggressive behavior. Testosterone varies seasonally, peaking when competition for mates is high and declining during parental care. Surprisingly, little is known about how testosterone mediates social conflict and parental care behavior in highly social species like cooperative breeders, where group members compete for breeding opportunities and provide parental or alloparental care. We examined how testosterone differs across breeding roles in the tropical cooperatively breeding superb starling, Lamprotornis superbus. We determined whether testosterone was elevated in larger groups, and whether testosterone was negatively related to total levels of parental and alloparental care. We found that male breeders had higher testosterone than male helpers and female breeders and helpers during incubation. However, breeding males exhibited a significant decline in testosterone from incubation to chick rearing, and all individuals had similar levels during the chick rearing stage. Additionally, helpers-but not breeders-in large social groups had higher testosterone than those in small groups. Finally, testosterone was not correlated with nestling provisioning rates during chick rearing, suggesting that natural variation in the low levels of testosterone observed during periods of high parental care does not affect nestling provisioning. Together, these results offer insight into how testosterone is related to breeding roles, intra-group conflict, and parental care in a highly social species.
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Affiliation(s)
- Alyxandra E Pikus
- Department of Ecology, Evolution and Environmental Biology, Columbia University, New York, NY 10027, USA
| | - Sarah Guindre-Parker
- Department of Ecology, Evolution and Environmental Biology, Columbia University, New York, NY 10027, USA; Department of Integrative Biology, University of Guelph, Guelph, ON N1G 2W1, Canada
| | - Dustin R Rubenstein
- Department of Ecology, Evolution and Environmental Biology, Columbia University, New York, NY 10027, USA; Center for Integrative Animal Behavior, Columbia University, New York, NY 10027, USA.
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26
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The function of ultrasonic vocalizations during territorial defence by pair-bonded male and female California mice. Anim Behav 2018. [DOI: 10.1016/j.anbehav.2017.11.008] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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27
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Fuxjager MJ, Miles MC, Goller F, Petersen J, Yancey J. Androgens Support Male Acrobatic Courtship Behavior by Enhancing Muscle Speed and Easing the Severity of Its Tradeoff With Force. Endocrinology 2017; 158:4038-4046. [PMID: 28938418 DOI: 10.1210/en.2017-00599] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Accepted: 08/23/2017] [Indexed: 01/08/2023]
Abstract
Steroid hormone action in the brain regulates many animals' elaborate social displays used for courtship and competition, but it is increasingly recognized that the periphery may also be a site for potent steroidal modulation of complex behavior. However, the mechanisms of such "bottom-up" regulation of behavioral outflow are largely unclear. To study this problem, we examined how androgenic sex hormones act through the skeletal muscular system to mediate elaborate courtship acrobatics in a tropical bird called the golden-collared manakin. As part of their display, males snap their wings together above their backs at rates that are at least 2× faster than the normal wing-beat frequency used for flight. This behavior, called the roll-snap, is actuated by repeatedly activating a humeral retractor muscle-the scapulohumeralis caudalis (SH)-which produces contraction-relaxation cycling speeds similar to the "superfast" muscles of other taxa. We report that endogenous androgenic activation of androgen receptor (AR) sustains this muscle's exceptionally rapid contractile kinetics, allowing the tissue to generate distinct wing movements at oscillation frequencies >100 Hz. We also show that these effects are rooted in an AR-dependent increase to contractile velocity, which incurs no detectable cost to force generation. Thus, AR enhances SH speed necessary for courtship display performance while avoiding the expected tradeoff with strength that could otherwise negatively influence aspects of flight. Peripheral AR therefore not only sets up the muscular system to perform a complex wing display, but does so in a way that balances the functional requirements of this muscle for other life-sustaining behavior.
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Affiliation(s)
- Matthew J Fuxjager
- Department of Biology, Wake Forest University, Winston-Salem, North Carolina 27109
| | - Meredith C Miles
- Department of Biology, Wake Forest University, Winston-Salem, North Carolina 27109
| | - Franz Goller
- Department of Biology, University of Utah, Salt Lake City, Utah 84112
| | - John Petersen
- Department of Biology, Wake Forest University, Winston-Salem, North Carolina 27109
| | - Julia Yancey
- Department of Biology, Wake Forest University, Winston-Salem, North Carolina 27109
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28
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Developmental changes in the histological structure of the testes, and testosterone profiles in male guinea fowls ( Numida meleagris ). Theriogenology 2017; 101:114-122. [DOI: 10.1016/j.theriogenology.2017.06.024] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2017] [Revised: 06/12/2017] [Accepted: 06/22/2017] [Indexed: 11/22/2022]
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29
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Moser-Purdy C, MacDougall-Shackleton SA, Bonier F, Graham BA, Boyer AC, Mennill DJ. Male song sparrows have elevated testosterone in response to neighbors versus strangers. Horm Behav 2017; 93:47-52. [PMID: 28434901 DOI: 10.1016/j.yhbeh.2017.04.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/01/2016] [Revised: 04/17/2017] [Accepted: 04/19/2017] [Indexed: 11/16/2022]
Abstract
Upon hearing a conspecific signal, animals must assess their relationship with the signaller and respond appropriately. Territorial animals usually respond more aggressively to strangers than neighbors in a phenomenon known as the "dear enemy effect". This phenomenon likely evolved because strangers represent a threat to an animal's territory tenure and parentage, whereas neighbors only represent a threat to an animal's parentage because they already possess a territory (providing territory boundaries are established and stable). Although the dear enemy effect has been widely documented using behavioral response variables, little research has been conducted on the physiological responses of animals to neighbors versus strangers. We sought to investigate whether the dear enemy effect is observed physiologically by exposing territorial male song sparrows (Melospiza melodia) to playback simulating a neighbor or a stranger, and then collecting blood samples to measure plasma testosterone levels. We predicted that song sparrows would exhibit increased testosterone levels after exposure to stranger playback compared to neighbor playback, due to the role testosterone plays in regulating aggression. Contrary to our prediction, we found that song sparrows had higher testosterone levels after exposure to neighbor playback compared to stranger playback. We discuss several explanations for our result, notably that corticosterone may regulate the dear enemy effect in male song sparrows and this may inhibit plasma testosterone. Future studies will benefit from examining corticosterone in addition to testosterone, to better understand the hormonal underpinnings of the dear enemy effect.
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Affiliation(s)
| | | | - Frances Bonier
- Biology Department, Queen's University, Kingston, ON K7L 3N6, Canada
| | - Brendan A Graham
- Department of Biological Sciences, University of Windsor, Windsor, ON N9B 3P4, Canada
| | - Andrea C Boyer
- Department of Biology, Western University, London, ON N6G 1G9, Canada
| | - Daniel J Mennill
- Department of Biological Sciences, University of Windsor, Windsor, ON N9B 3P4, Canada.
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Mayer M, Zedrosser A, Rosell F. Couch potatoes do better: Delayed dispersal and territory size affect the duration of territory occupancy in a monogamous mammal. Ecol Evol 2017. [PMID: 28649346 PMCID: PMC5478066 DOI: 10.1002/ece3.2988] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022] Open
Abstract
In territorial, socially monogamous species, the establishment and defense of a territory are an important strategy to maximize individual fitness, but the factors responsible for the duration of territory occupancy are rarely studied, especially in long‐lived mammals. A long‐term monitoring program in southeast Norway spanning over 18 years allowed us to follow the individual life histories of Eurasian beavers (Castor fiber) from adolescence in their natal family group to dispersal and territory establishment until the end of territory occupancy. We investigated whether territory size, resource availability, population density, and dispersal age could explain the duration of territory occupancy, which ranged from 1 to 11 years. The duration of territory occupancy was positively related to dispersal age, suggesting that individuals that delayed dispersal had a competitive advantage due to a larger body mass. This is in support with the maturation hypothesis, which states that an animal should await its physical and behavioral maturation before the acquisition of a territory. Further, we found that individuals that established in medium‐sized territories occupied them longer as compared to individuals in small or large territories. This suggests that large territories are more costly to defend due to an increased patrolling effort, and small territories might not have sufficient resources. The lifetime reproductive success ranged from zero to six kits and generally increased with an increasing duration of territory occupancy. Our findings show the importance of holding a territory and demonstrate that dispersal decisions and territory selection have important consequences for the fitness of an individual.
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Affiliation(s)
- Martin Mayer
- Faculty of Technology, Natural Sciences and Maritime Sciences Department of Natural Sciences and Environmental Health University College of Southeast Norway Bø i Telemark Norway
| | - Andreas Zedrosser
- Faculty of Technology, Natural Sciences and Maritime Sciences Department of Natural Sciences and Environmental Health University College of Southeast Norway Bø i Telemark Norway.,Department of Integrative Biology Institute of Wildlife Biology and Game Management University of Natural Resources and Life Sciences Vienna Austria
| | - Frank Rosell
- Faculty of Technology, Natural Sciences and Maritime Sciences Department of Natural Sciences and Environmental Health University College of Southeast Norway Bø i Telemark Norway
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Mishra I, Singh D, Kumar V. Seasonal alterations in the daily rhythms in hypothalamic expression of genes involved in the photoperiodic transduction and neurosteroid-dependent processes in migratory blackheaded buntings. J Neuroendocrinol 2017; 29. [PMID: 28295708 DOI: 10.1111/jne.12469] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Revised: 03/09/2017] [Accepted: 03/09/2017] [Indexed: 01/23/2023]
Abstract
The present study investigated seasonal alterations in the daily rhythms of hypothalamic expression of genes involved in the photoperiodic regulation of annual cycles in birds. We measured the 4-hourly mRNA expression of genes involved in the photoperiodic transduction (OPN5, EYA3, CGA, TSHβ, DIO2, DIO3) and neurosteroid-dependent processes (AR, CYP19, ERα, ERβ) in the hypothalamus of migratory blackheaded buntings photoinduced with photosensitive, photostimulated (early and late stimulated) and photorefractory seasonal states. There were significant differences in daily mRNA profiles between the photoperiodic states. Particularly, increased CGA, TSHβ and DIO2 and decreased DIO3 mRNA levels in the early photostimulated state, compared to the photosensitive state, suggest that thyroid hormones have a role in photostimulation in buntings. Similar differences in the expression of genes coding for the aromatase enzyme (CYP19) and receptors for oestrogen (ERα, ERβ) (but not androgen; AR) indicate that there is seasonal alteration in the neuro-oestrogen-mediated functions. Furthermore, peak expression times of CGA, TSHβ and DIO2 genes at hours 14-15 of the day in the early stimulated state indicated molecular regulation of the daily rhythm of photoinducibility in buntings. Most significantly, however, we found an attenuated daily rhythm in thyroid hormone modulatory genes and a switch of peak expression time from day to night in CYP19 mRNA rhythm in the subsequent late photostimulated state, although testicular maturation still persisted. These alterations in daily rhythms may have signalled the initiation of processes underlying other seasonal phenologies in parallel with the gonadal response, such as a manifestation of the night-time flight in buntings. These results show alterations in daily rhythms underlying the transcriptional regulation of the photoperiod-induced seasonal states in migratory blackheaded buntings.
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Affiliation(s)
- I Mishra
- Department of Zoology, IndoUS Center for Biological Timing, University of Delhi, Delhi, India
| | - D Singh
- Department of Zoology, IndoUS Center for Biological Timing, University of Delhi, Delhi, India
| | - V Kumar
- Department of Zoology, IndoUS Center for Biological Timing, University of Delhi, Delhi, India
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Apfelbeck B, Mortega KG, Flinks H, Illera JC, Helm B. Testosterone, territorial response, and song in seasonally breeding tropical and temperate stonechats. BMC Evol Biol 2017; 17:101. [PMID: 28412929 PMCID: PMC5392926 DOI: 10.1186/s12862-017-0944-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2016] [Accepted: 03/23/2017] [Indexed: 11/23/2022] Open
Abstract
Background Testosterone facilitates physiological, morphological, and behavioral changes required for breeding in male vertebrates. However, testosterone concentrations and the link between its seasonal changes and those in reproductive behaviors vary greatly among species. To better understand the impact of tropical and temperate environments and life history factors on this variation, we have compared testosterone, territorial behavior and song performance across sequential stages of the breeding season in males of 16 closely related taxa of East African tropical and West European temperate stonechats (Saxicola spp), which all breed during a short breeding season, but differ in migratory behavior, seasonal territory-acquisition and pace of life. Results We found that generally, the profiles of testosterone and territorial behavior were similar across latitudes. African stonechats with a slow pace of life had equally high peak testosterone concentrations and responded as aggressively to an intruder as European stonechats with a fast pace of life. However, song performance at the beginning of the breeding season was lower in African than in European stonechats. The differences in song performance were not associated with variation in testosterone levels between tropical and temperate stonechats. Conclusions The results suggest a very similar role for testosterone as a mediator of high intensity territorial aggression during the fertile period of females in tropical and temperate stonechats, which all are highly seasonal, locally synchronous breeders. A potential explanation may be high risk of extra-pair copulations which has been associated with synchronous breeding. Interestingly, an association was not consistent for song performance. Our data suggest that song performance can be disassociated from peak testosterone levels depending on its role in breeding behavior. Despite similar testosterone levels, European males, which early in the breeding season acquire territories and mates, showed greater song performance than African stonechats, which maintain year-round territories and pair-bonds. Taken together, our study comparing related taxa of old world songbirds suggests that short breeding seasons may be a major selective force for high peak testosterone levels during breeding regardless of latitude and pace of life, but that particular behaviors, in our case song, can be uncoupled from peak testosterone levels. Electronic supplementary material The online version of this article (doi:10.1186/s12862-017-0944-9) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Beate Apfelbeck
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, Scotland, G12 8QQ, UK. .,Terrestrial Ecology Research Group, Department of Ecology and Ecosystemmanagement, Technische Universität München, School of Life Sciences Weihenstephan, D-85354, Freising, Germany.
| | - Kim G Mortega
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, Scotland, G12 8QQ, UK.,Department of Migration and Immunoecology, Max-Planck-Institut für Ornithologie, D-78315 Radolfzell, Germany
| | | | - Juan Carlos Illera
- Research Unit of Biodiversity (UO-CSIC-PA), Oviedo University, Campus of Mieres, 33600, Mieres, Spain
| | - Barbara Helm
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, Scotland, G12 8QQ, UK
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Mishra I, Bhardwaj SK, Malik S, Kumar V. Concurrent hypothalamic gene expression under acute and chronic long days: Implications for initiation and maintenance of photoperiodic response in migratory songbirds. Mol Cell Endocrinol 2017; 439:81-94. [PMID: 27789391 DOI: 10.1016/j.mce.2016.10.023] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/12/2016] [Revised: 10/19/2016] [Accepted: 10/22/2016] [Indexed: 01/22/2023]
Abstract
Hypothalamic expression of the thyroid hormone (TH) responsive gonadostimulatory (eya3, cga, tshβ, dio2, dio3, gnrh, gnih) and neurosteroid pathway genes (androgen receptor [ar], aromatase [cyp19], estrogen receptor [er] α and β) was examined in photosensitive redheaded buntings exposed to 2 (acute, experiment 1) or 12 (chronic, experiment 2) long days (16L:8D). Experiment 2 also included a photorefractory group. Acute long days caused a significant increase in eya3, cga, tshβ, dio2 and gnrh and decrease in dio3 mRNA levels. eya3, cga and tshβ expressions were unchanged after the chronic long days. We also found increased cyp19, erα and erβ mRNA levels after acute, and increased cyp19 and decreased erβ levels after the chronic long-day exposure. Photorefractory buntings showed expression patterns similar to that in the photosensitive state, except for high gnrh and gnih and low dio3 mRNA levels. Consistent with gene expression patterns, there were changes in fat deposition, body mass, testis size, and plasma levels of testosterone, tri-iodothyronine and thyroxine. These results show concurrent photostimulation of the TH-signalling and neurosteroid pathways, and extend the idea, based on differences in gene expression, that transitions in seasonal photoperiodic states are accomplished at the transcriptional levels in absolute photorefractory species.
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Affiliation(s)
- Ila Mishra
- IndoUS Center for Biological Timing, Department of Zoology, University of Delhi, Delhi 110 007, India
| | | | - Shalie Malik
- Department of Zoology, University of Lucknow, Lucknow 226 007, India
| | - Vinod Kumar
- IndoUS Center for Biological Timing, Department of Zoology, University of Delhi, Delhi 110 007, India.
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Apfelbeck B, Flinks H, Goymann W. Territorial aggression does not feed back on testosterone in a multiple-brooded songbird species with breeding and non-breeding season territoriality, the European stonechat. Horm Behav 2017; 87:89-95. [PMID: 27838361 DOI: 10.1016/j.yhbeh.2016.11.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/03/2016] [Revised: 11/04/2016] [Accepted: 11/04/2016] [Indexed: 11/20/2022]
Abstract
Testosterone mediates reproductive behaviours in male vertebrates. For example, breeding season territoriality depends on testosterone in many species of birds and in some, territorial interactions feed back on testosterone concentrations. However, the degree to which territorial behaviour and testosterone are associated differs even between species with seemingly similar life histories, especially between species that also defend territories outside the breeding season. Here, we investigate the link between territorial behaviour and testosterone in European stonechats. Previous studies found that territorial aggression in stonechats depends on testosterone in a breeding, but not in a non-breeding context. We investigated whether stonechats show a rise in testosterone during simulated territorial intrusions (STI) during the breeding season. Post-capture testosterone concentrations of males caught after an STI were not higher than those of males caught in a control situation regardless of breeding stage. However, most of the males would have been able to mount a testosterone response because the same individuals that did not increase testosterone during the STI showed a substantial increase in testosterone after injections of gonadotropin-releasing hormone (GnRH). GnRH-induced and post-capture testosterone concentrations were positively correlated and both decreased with successive breeding stages. Further, territory owners with a short latency to attack the decoy expressed higher post-capture testosterone concentrations than males with a longer latency to attack the decoy. Thus, there is no evidence for behavioural feedback on testosterone concentrations during male-male interactions in stonechats. In combination with previous studies our data suggest that testosterone functions as an on/off switch of high intensity territorial aggression during the breeding season in stonechats. The among-species variation in the androgen control of territorial behaviour may be only partly a result of environmental differences. Instead, potential differences in how territoriality evolved in different species may have influenced whether and how a reproductive hormone such as testosterone was co-opted into the mechanistic control of territorial behaviour.
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Affiliation(s)
- Beate Apfelbeck
- Abteilung für Verhaltensneurobiologie, Max-Planck-Institut für Ornithologie, Eberhard-Gwinner-Straße 6a, D-82319 Seewiesen, Germany; Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, G12 8QQ, Scotland, UK; Department of Ecology and Ecosystem management, Technische Universität München, D-85354 Freising, Germany.
| | | | - Wolfgang Goymann
- Abteilung für Verhaltensneurobiologie, Max-Planck-Institut für Ornithologie, Eberhard-Gwinner-Straße 6a, D-82319 Seewiesen, Germany
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35
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Quintana L, Zubizarreta L, Jalabert C, Batista G, Perrone R, Silva A. Building the case for a novel teleost model of non-breeding aggression and its neuroendocrine control. ACTA ACUST UNITED AC 2016; 110:224-232. [PMID: 27915075 DOI: 10.1016/j.jphysparis.2016.11.009] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Revised: 09/16/2016] [Accepted: 11/23/2016] [Indexed: 10/20/2022]
Abstract
In vertebrates, aggression has been traditionally associated with high levels of circulating androgens in breeding males. Nevertheless, the centrality of androgens as primary modulators of aggression is being reconsidered in at least in two particular cases: (1) territorial aggression outside the breeding season, and (2) aggression by females. We are developing the weakly electric fish, Gymnotus omarorum, as a novel, advantageous model system to address these two alternative forms of aggression. This species displays a short, escalated contest, after which a clear hierarchical status emerges. Subordination of individuals involves three sequential decisions: interruptions of their electric discharges, retreats, and chirps. These decisions are influenced by both size asymmetry between contenders and aggression levels of dominants. Both females and males are aggressive, and do not differ in fighting ability nor in the value placed on the resource. Aggression is completely independent of gonadal hormones: dominance status is unrelated to circulating androgen and estrogen levels, and gonadectomy in males does not affect aggression. Nevertheless, estrogenic pathways participate in the modulation of this non-breeding aggression. Our results parallel those put forth in other taxa, heightening the value of G. omarorum as a model to identify commonalities in neuroendrocrine strategies of vertebrate aggression control.
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Affiliation(s)
- Laura Quintana
- Unidad Bases Neurales de la Conducta, Departamento de Neurofisiología Celular y Molecular, Instituto de Investigaciones Biológicas Clemente Estable, Avda. Italia 3318, 11600 Montevideo, Uruguay.
| | - Lucía Zubizarreta
- Unidad Bases Neurales de la Conducta, Departamento de Neurofisiología Celular y Molecular, Instituto de Investigaciones Biológicas Clemente Estable, Avda. Italia 3318, 11600 Montevideo, Uruguay; Laboratorio de Neurofisiología Celular y Sináptica, Departamento de Fisiología, Facultad de Medicina, Universidad de la República, General Flores 2125, Montevideo, Uruguay.
| | - Cecilia Jalabert
- Unidad Bases Neurales de la Conducta, Departamento de Neurofisiología Celular y Molecular, Instituto de Investigaciones Biológicas Clemente Estable, Avda. Italia 3318, 11600 Montevideo, Uruguay.
| | - Gervasio Batista
- Unidad Bases Neurales de la Conducta, Departamento de Neurofisiología Celular y Molecular, Instituto de Investigaciones Biológicas Clemente Estable, Avda. Italia 3318, 11600 Montevideo, Uruguay.
| | - Rossana Perrone
- Unidad Bases Neurales de la Conducta, Departamento de Neurofisiología Celular y Molecular, Instituto de Investigaciones Biológicas Clemente Estable, Avda. Italia 3318, 11600 Montevideo, Uruguay.
| | - Ana Silva
- Unidad Bases Neurales de la Conducta, Departamento de Neurofisiología Celular y Molecular, Instituto de Investigaciones Biológicas Clemente Estable, Avda. Italia 3318, 11600 Montevideo, Uruguay; Laboratorio de Neurociencias, Departamento de Biología Celular y Molecular, Facultad de Ciencias, Universidad de la República, Iguá 4225, Montevideo, Uruguay.
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36
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York JE, Radford AN, de Vries B, Groothuis TG, Young AJ. Dominance-related seasonal song production is unrelated to circulating testosterone in a subtropical songbird. Gen Comp Endocrinol 2016; 233:43-52. [PMID: 27179883 PMCID: PMC4920672 DOI: 10.1016/j.ygcen.2016.05.011] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/10/2015] [Revised: 04/30/2016] [Accepted: 05/10/2016] [Indexed: 02/07/2023]
Abstract
Circulating testosterone (T) is widely considered to play a key role in the production of sexual displays by male vertebrates. While numerous studies support a role for circulating T in promoting the production of song in male birds, this understanding is based primarily on evidence from seasonally breeding northern temperate species, leaving it unclear whether this mechanism generalizes to other regions of the world. Here we investigate whether variation in circulating levels of T can explain the marked within- and among-individual variation in male song performance observed in a subtropical population of the year-round territorial white-browed sparrow weaver (Plocepasser mahali mahali). Our findings reveal that both circulating T and male song production peaked at a similar time point, halfway through the population-level breeding season. However, while dominant males were more likely to sing and sang for longer than subordinate males, within-group paired comparisons revealed no dominance-related differences in circulating T. Moreover, comparisons both among and within individual dominant males revealed that song duration, syllable rate and proportion of time spent singing were all unrelated to circulating T. Together, our findings suggest that natural variation in male song production, at least in this population of white-browed sparrow weavers, is achieved principally through mechanisms other than variation in circulating T concentration. More widely, our results are in line with the view that male song production is not exclusively regulated by gonadally synthesized steroids.
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Affiliation(s)
- Jenny E York
- Centre for Life and Environmental Sciences, University of Exeter, Penryn Campus, Cornwall TR10 9EZ, UK; School of Biological Sciences, Life Sciences Building, 24 Tyndall Avenue, Bristol BS8 1TQ, UK.
| | - Andrew N Radford
- School of Biological Sciences, Life Sciences Building, 24 Tyndall Avenue, Bristol BS8 1TQ, UK
| | - Bonnie de Vries
- Behavioural Biology, The Groningen Institute for Evolutionary Life Sciences, University of Groningen, The Netherlands
| | - Ton G Groothuis
- Behavioural Biology, The Groningen Institute for Evolutionary Life Sciences, University of Groningen, The Netherlands
| | - Andrew J Young
- Centre for Life and Environmental Sciences, University of Exeter, Penryn Campus, Cornwall TR10 9EZ, UK
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Russ A, Reitemeier S, Weissmann A, Gottschalk J, Einspanier A, Klenke R. Seasonal and urban effects on the endocrinology of a wild passerine. Ecol Evol 2015; 5:5698-710. [PMID: 27069618 PMCID: PMC4813110 DOI: 10.1002/ece3.1820] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2015] [Revised: 10/14/2015] [Accepted: 10/15/2015] [Indexed: 11/27/2022] Open
Abstract
In order to maximize their fitness, organisms in seasonal environments rely on external cues to optimally time their life-history stages. One of the most important zeitgeber to time reproduction is the photoperiod, but further environmental cues are assessed to fine-tune reproduction due to year-to-year variation in environmental conditions. However, in urbanized environments, the pervasive artificial light at night has altered the natural signal of light and darkness. Accordingly, artificial light at night was repeatedly shown to affect avian reproductive physiology and to advance seasonal reproduction in birds. However, these experiments were mainly conducted in the absence of further environmental cues to facilitate the investigation of the mechanisms which are still poorly understood. Here, we investigate whether the endocrine system of free-ranging European blackbirds (Turdus merula) correlates with the amount of artificial light at night along a rural to urban gradient while the birds still encounter complementary environmental cues including seasonal variation in day length and temperature. Testosterone and estrone were assessed as metabolites in fecal samples and corticosterone in blood from mist-netted blackbirds. We demonstrate that seasonal fluctuations in abiotic factors, individual conditions, but also light at night affect the reproductive and stress physiology of wild European blackbirds. Elevated artificial night light intensities were significantly positively correlated with corticosterone and negatively with female estrone levels. No effects of artificial light were found for testosterone levels. Our results suggest that female blackbirds in particular perceive even low levels of artificial light at night as a weak but chronic stressor that interacts with the hypothalamic-pituitary-gonadal axis and leads to a reduced secretion of reproductive hormones. These findings point out that the impacts of light pollution are diverse and we only slowly disentangle its multiple effects on physiology, ecology, and biodiversity.
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Affiliation(s)
- Anja Russ
- Department of Conservation BiologyHelmholtz‐Centre for Environmental Research ‐ UFZPermoserstraße 1504318LeipzigGermany
| | - Susanne Reitemeier
- Institute of Physiological ChemistryUniversity of LeipzigAn den Tierkliniken 104103LeipzigGermany
| | - Anne Weissmann
- Institute of Physiological ChemistryUniversity of LeipzigAn den Tierkliniken 104103LeipzigGermany
| | - Jutta Gottschalk
- Institute of Physiological ChemistryUniversity of LeipzigAn den Tierkliniken 104103LeipzigGermany
| | - Almuth Einspanier
- Institute of Physiological ChemistryUniversity of LeipzigAn den Tierkliniken 104103LeipzigGermany
| | - Reinhard Klenke
- Department of Conservation BiologyHelmholtz‐Centre for Environmental Research ‐ UFZPermoserstraße 1504318LeipzigGermany
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DeVries MS, Winters CP, Jawor JM. Testosterone might not be necessary to support female aggression in incubating northern cardinals. Anim Behav 2015. [DOI: 10.1016/j.anbehav.2015.06.016] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
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Jalabert C, Quintana L, Pessina P, Silva A. Extra-gonadal steroids modulate non-breeding territorial aggression in weakly electric fish. Horm Behav 2015; 72:60-7. [PMID: 25989595 DOI: 10.1016/j.yhbeh.2015.05.003] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/14/2015] [Revised: 05/04/2015] [Accepted: 05/11/2015] [Indexed: 01/03/2023]
Abstract
The neuroendocrine control of intraspecific aggression is a matter of current debate. Although aggression in a reproductive context has been associated with high levels of circulating androgens in a broad range of species, it has also been shown to occur during the non-breeding season when gonads are regressed and plasma steroid hormone levels are low. In mammals and birds the aromatization of androgens into estrogens plays a key role in the regulation of aggression in both the breeding and non-breeding seasons. This is the first study in a teleost fish to explore the role of steroids in the modulation of non-breeding aggression. Gymnotus omarorum is a highly aggressive teleost fish that exhibits aggression all year-round. We analyzed male-male non-breeding agonistic behavior, compared circulating 11-Ketotestosterone (11-KT) levels between dominants and isolated males, assessed the regulatory role of aromatization of androgens into estrogens, and evaluated the gonads as a source of these sex steroids. We found that high levels of aggression occurred in the non-breeding season despite low plasma 11-KT levels, and that there was no difference in 11-KT levels between dominant and isolated males. We demonstrated that acute aromatase inhibition decreased aggression, distorted contest dynamics, and affected expected outcome. We also found that castrated individuals displayed aggressive behavior indistinguishable from non-castrated males. Our results show, for the first time in teleost fish, that territorial aggression of G. omarorum during the non-breeding season depends on a non-gonadal estrogenic pathway.
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Affiliation(s)
- Cecilia Jalabert
- Unidad Bases Neurales de la Conducta, Instituto de Investigaciones Biológicas Clemente Estable, Montevideo 11600, Uruguay
| | - Laura Quintana
- Unidad Bases Neurales de la Conducta, Instituto de Investigaciones Biológicas Clemente Estable, Montevideo 11600, Uruguay
| | - Paula Pessina
- Laboratorio de Técnicas Nucleares, Facultad de Veterinaria, Universidad de la Republica, Montevideo 11600, Uruguay
| | - Ana Silva
- Unidad Bases Neurales de la Conducta, Instituto de Investigaciones Biológicas Clemente Estable, Montevideo 11600, Uruguay; Laboratorio de Neurociencias, Facultad de Ciencias, Universidad de la Republica, Montevideo 11400, Uruguay.
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McEvoy J, While GM, Jones SM, Wapstra E. Examining the role of testosterone in mediating short-term aggressive responses to social stimuli in a lizard. PLoS One 2015; 10:e0125015. [PMID: 25906149 PMCID: PMC4407986 DOI: 10.1371/journal.pone.0125015] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2014] [Accepted: 03/19/2015] [Indexed: 11/18/2022] Open
Abstract
Hormones have been suggested as a key proximate mechanism that organize and maintain consistent individual differences in behavioural traits such as aggression. The steroid hormone testosterone in particular has an important activational role in mediating short-term aggressive responses to social and environmental stimuli within many vertebrate systems. We conducted two complementary experiments designed to investigate the activational relationship between testosterone and aggression in male Egernia whitii, a social lizard species. First, we investigated whether a conspecific aggressive challenge induced a testosterone response and second, we artificially manipulated testosterone concentrations to examine whether this changed aggression levels. We found that at the mean level, plasma T concentration did not appear to be influenced by an aggression challenge. However, there was a slight indication that receiving a challenge may influence intra-individual consistency of plasma T concentrations, with individuals not receiving an aggression challenge maintaining consistency in their circulating testosterone concentrations, while those individuals that received a challenge did not. Manipulating circulating testosterone concentrations had no influence on either mean-level or individual-level aggression. Combined with our previous work, our study adds increasing evidence that the relationship between testosterone and aggression is not straightforward, and promotes the investigation of alternative hormonal pathways and differences in neuro-synthesis and neuroendocrine pathways to account for species variable testosterone - aggression links.
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Affiliation(s)
- Jo McEvoy
- School of Biological Sciences, University of Tasmania, Hobart, Tasmania, Australia
- * E-mail:
| | - Geoffrey M. While
- School of Biological Sciences, University of Tasmania, Hobart, Tasmania, Australia
- Edward Grey Institute, Department of Zoology, University of Oxford, Oxford, United Kingdom
| | - Susan M. Jones
- School of Biological Sciences, University of Tasmania, Hobart, Tasmania, Australia
| | - Erik Wapstra
- School of Biological Sciences, University of Tasmania, Hobart, Tasmania, Australia
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van der Westhuizen D, Solms M. Basic emotional foundations of social dominance in relation to Panksepp's affective taxonomy. ACTA ACUST UNITED AC 2015. [DOI: 10.1080/15294145.2015.1021371] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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Soma KK, Rendon NM, Boonstra R, Albers HE, Demas GE. DHEA effects on brain and behavior: insights from comparative studies of aggression. J Steroid Biochem Mol Biol 2015; 145:261-72. [PMID: 24928552 DOI: 10.1016/j.jsbmb.2014.05.011] [Citation(s) in RCA: 86] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/27/2014] [Revised: 05/09/2014] [Accepted: 05/15/2014] [Indexed: 12/24/2022]
Abstract
Historically, research on the neuroendocrinology of aggression has been dominated by the paradigm that the brain receives sex steroid hormones, such as testosterone (T), from the gonads, and then these gonadal hormones modulate behaviorally relevant neural circuits. While this paradigm has been extremely useful for advancing the field, recent studies reveal important alternatives. For example, most vertebrate species are seasonal breeders, and many species show aggression outside of the breeding season, when the gonads are regressed and circulating levels of gonadal steroids are relatively low. Studies in diverse avian and mammalian species suggest that adrenal dehydroepiandrosterone (DHEA), an androgen precursor and prohormone, is important for the expression of aggression when gonadal T synthesis is low. Circulating DHEA can be converted into active sex steroids within the brain. In addition, the brain can synthesize sex steroids de novo from cholesterol, thereby uncoupling brain steroid levels from circulating steroid levels. These alternative mechanisms to provide sex steroids to specific neural circuits may have evolved to avoid the costs of high circulating T levels during the non-breeding season. Physiological indicators of season (e.g., melatonin) may allow animals to switch from one neuroendocrine mechanism to another across the year. DHEA and neurosteroids are likely to be important for the control of multiple behaviors in many species, including humans. These studies yield fundamental insights into the regulation of DHEA secretion, the mechanisms by which DHEA affects behavior, and the brain regions and neural processes that are modulated by DHEA. It is clear that the brain is an important site of DHEA synthesis and action. This article is part of a Special Issue entitled 'Essential role of DHEA'.
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Affiliation(s)
- Kiran K Soma
- Departments of Psychology and Zoology, Graduate Program in Neuroscience, and the Brain Research Centre, University of British Columbia, Vancouver, BC, Canada V6T 1Z4.
| | - Nikki M Rendon
- Department of Biology, Program in Neuroscience, and Center for the Integrative Study of Animal Behavior, Indiana University, Bloomington, IN 47405, USA
| | - Rudy Boonstra
- Centre for Neurobiology of Stress, Department of Biological Sciences, University of Toronto Scarborough, Toronto, ON, Canada M1C 1A4
| | - H Elliott Albers
- Neuroscience Institute, and Center for Behavioral Neuroscience, Georgia State University, Atlanta, GA 30303, USA
| | - Gregory E Demas
- Department of Biology, Program in Neuroscience, and Center for the Integrative Study of Animal Behavior, Indiana University, Bloomington, IN 47405, USA
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Gonçalves-de-Freitas E, Carvalho TB, Oliveira RF. Photoperiod modulation of aggressive behavior is independent of androgens in a tropical cichlid fish. Gen Comp Endocrinol 2014; 207:41-9. [PMID: 25101841 DOI: 10.1016/j.ygcen.2014.07.024] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/25/2013] [Revised: 07/16/2014] [Accepted: 07/17/2014] [Indexed: 10/24/2022]
Abstract
Photoperiod is a major environmental cue that signals breeding conditions in animals living in temperate climates. Therefore, the activity of the reproductive (i.e. hypothalamic-pituitary-gonadal, HPG) axis and of the expression of reproductive behaviors, including territoriality, is responsive to changes in day length. However, at low latitudes the seasonal variation in day length decreases dramatically and photoperiod becomes less reliable as a breeding entraining cue in tropical species. In spite of this, some tropical mammals and birds have been found to still respond to small amplitude changes in photoperiod (e.g. 17min). Here we tested the effect of 2 photoperiod regimes, referred to as long-day (LD: 16L:08D) and short-day (SD: 08L:16D), on the activity of the HPG axis, on aggressive behavior and in the androgen response to social challenges in males of the tropical cichlid fish Tilapia rendalli. For each treatment, fish were transferred from a pre-treatment photoperiod of 12L:12D to their treatment photoperiod (either LD or SD) in which they were kept for 20days on stock tanks. Afterwards, males were isolated for 4days in glass aquaria in order to establish territories and initial androgen levels (testosterone, T; 11-ketotestosterone, KT) were assessed. On the 4th day, territorial intrusions were promoted such that 1/3 of the isolated males acted as residents and another 1/3 as intruders. Territorial intrusions lasted for 1h to test the effects of a social challenge under different photoperiod regimes. Photoperiod treatment (either SD or LD) failed to induce significant changes in the HPG activity, as measured by androgen levels and gonadosomatic index. However, SD increased the intensity of aggressive behaviors and shortened the time to settle a dominance hierarchy in an androgen-independent manner. The androgen responsiveness to the simulated territorial intrusion was only present in KT but not for T. The percent change in KT levels in response to the social challenge was different between treatments (SD>LD) and between male types (resident>intruder). The higher androgen response to a social challenge in residents under SD may be explained by the time course of the androgen response that due to the long time it takes to fight resolution under LD, might have been delayed. This result illustrates the importance of incorporating time response data in social endocrinology studies.
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Affiliation(s)
- Eliane Gonçalves-de-Freitas
- Universidade Estadual Paulista e Centro de Aquicultura da UNESP, R. Cristóvão Colombo 2265, 15054-000 São José do Rio Preto, SP, Brazil.
| | - Thaís Billalba Carvalho
- Universidade Federal do Amazonas, Av. Gal. Rodrigo Octávio Jordão Ramos 3000, Manaus, AM, Brazil.
| | - Rui F Oliveira
- ISPA - Instituto Universitário, R. Jardim do Tabaco 34, 1149-041 Lisboa, Portugal; Champalimaud Neuroscience Programme, Instituto Gulbenkian de Ciência, Rua da Quinta Grande 6, 2780-156 Oeiras, Portugal.
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Golinski A, Kubička L, John-Alder H, Kratochvíl L. Elevated testosterone is required for male copulatory behavior and aggression in Madagascar ground gecko (Paroedura picta). Gen Comp Endocrinol 2014; 205:133-41. [PMID: 24852349 DOI: 10.1016/j.ygcen.2014.05.012] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/15/2013] [Revised: 05/01/2014] [Accepted: 05/06/2014] [Indexed: 11/22/2022]
Abstract
Elevated levels of gonadal androgens are often required for the expression of male-specific behavioral and morphological traits in all classes of vertebrates, including reptiles. Here, we tested the role of male gonadal androgens in the control of male sexual behavior, aggressive behavior, and size of the hemipenes in the gecko Paroedura picta. We performed hormonal manipulations involving castration with and without testosterone (T) replacement in males and application of exogenous T and ovariectomy in females. Castration suppressed sexual behavior and hemipenes size in males, and these effects were fully rescued by exogenous T. Sexual behavior and growth of the hemipenes were masculinized by male-typical levels of T in females, while ovariectomized females retained female-typical expression of these traits. These results indicate that the development of male sexual behavior in adult females does not require early or pubertal organization. Elevated T increased the likelihood of aggressive behavior directed toward a male intruder, but aggression occurred only rarely. Elevated T is necessary and sufficient for enlargement of the hemipenes and the expression of male sexual behavior in both males and females of Paroedura picta. In contrast to sexual behavior, the expression of aggressive behavior is apparently more dependent on other factors in addition to T itself.
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Affiliation(s)
- Alison Golinski
- Graduate Program in Endocrinology and Animal Biosciences, Rutgers University, 84 Lipman Drive, New Brunswick, NJ 08901, USA
| | - Lukáš Kubička
- Department of Ecology, Faculty of Science, Charles University in Prague, Viničná 7, 128 43 Praha 2, Czech Republic.
| | - Henry John-Alder
- Department of Ecology, Evolution, and Natural Resources, Rutgers University, 14 College Farm Road, New Brunswick, NJ 08901, USA
| | - Lukáš Kratochvíl
- Department of Ecology, Faculty of Science, Charles University in Prague, Viničná 7, 128 43 Praha 2, Czech Republic
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Touchton JM, Seddon N, Tobias JA. Captive rearing experiments confirm song development without learning in a tracheophone suboscine bird. PLoS One 2014; 9:e95746. [PMID: 24788343 PMCID: PMC4005748 DOI: 10.1371/journal.pone.0095746] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2014] [Accepted: 03/29/2014] [Indexed: 12/01/2022] Open
Abstract
The origin of vocal learning in animals has long been the subject of debate, but progress has been limited by uncertainty regarding the distribution of learning mechanisms across the tree of life, even for model systems such as birdsong. In particular, the importance of learning is well known in oscine songbirds, but disputed in suboscines. Members of this diverse group (∼1150 species) are generally assumed not to learn their songs, but empirical evidence is scarce, with previous studies restricted to the bronchophone (non-tracheophone) clade. Here, we conduct the first experimental study of song development in a tracheophone suboscine bird by rearing spotted antbird (Hylophylax naevioides) chicks in soundproofed aviaries. Individuals were raised either in silence with no tutor or exposed to standardized playback of a heterospecific tutor. All individuals surviving to maturity took a minimum of 79 days to produce a crystallized version of adult song, which in all cases was indistinguishable from wild song types of their own species. These first insights into song development in tracheophone suboscines suggest that adult songs are innate rather than learnt. Given that empirical evidence for song learning in suboscines is restricted to polygamous and lek-mating species, whereas tracheophone suboscines are mainly monogamous with long-term social bonds, our results are consistent with the view that sexual selection promotes song learning in birds.
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Affiliation(s)
- Janeene M. Touchton
- Smithsonian Tropical Research Institute, Balboa, Panama
- Max Planck Institute for Ornithology, Radolfzell, Germany
- * E-mail:
| | - Nathalie Seddon
- Edward Grey Institute, Department of Zoology, University of Oxford, Oxford, United Kingdom
| | - Joseph A. Tobias
- Edward Grey Institute, Department of Zoology, University of Oxford, Oxford, United Kingdom
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Vergauwen J, Groothuis TGG, Eens M, Müller W. Testosterone influences song behaviour and social dominance - but independent of prenatal yolk testosterone exposure. Gen Comp Endocrinol 2014; 195:80-7. [PMID: 24211320 DOI: 10.1016/j.ygcen.2013.10.014] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/24/2013] [Revised: 09/03/2013] [Accepted: 10/17/2013] [Indexed: 01/23/2023]
Abstract
In the last two decades, maternally derived yolk androgens have been shown to significantly alter offspring development, and a number of these effects persist into adulthood. However, little is known about their underlying mechanisms. Mechanisms that have been suggested are changes in the endogenous androgen production post-hatching or changes in the sensitivity towards circulating androgens. We tested the effects of yolk testosterone on the plasma testosterone levels and the sensitivity to testosterone in 5months old male canaries that hatched from eggs that were either injected with testosterone (yT-males) or with a control solution (yC-males). Changes in sensitivity were investigated via the behavioural response to an experimental elevation of the plasma testosterone levels. We performed the experiment in fall (low endogenous testosterone production), focusing on testosterone dependent response traits (aggression and song). Before implantation, there was a non-significant trend that the plasma testosterone levels were lower in yT-males than in yC-males. Elevating the plasma testosterone concentrations increased aggressiveness, song bout length and similarity of repeated song elements (=consistency), with the latter likely being a consequence of testosterone-driven song crystallization. However, these effects were not different among yT- or yC-males in any of the parameters. Thus, our findings render it unlikely that changes in the sensitivity to testosterone post-hatching would form the main underlying mechanism of hormone-mediated maternal effects in birds. Further experiments are urgently needed in order to understand the nature of the phenotypic effects resulting from embryonic exposure to maternal yolk testosterone.
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Affiliation(s)
- Jonas Vergauwen
- Department of Biology - Ethology, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, Belgium
| | - Ton G G Groothuis
- Department of Behavioural Biology, University of Groningen, Nijenborgh 7, 9747AG Groningen, The Netherlands
| | - Marcel Eens
- Department of Biology - Ethology, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, Belgium
| | - Wendt Müller
- Department of Biology - Ethology, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, Belgium.
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Tumkiratiwong P, Poothong S, Taksintum W, Suekkhachat H, Kanchanabanca P, Suwapat P. Annual Changes in Fecal Sex Hormones with Corresponding Changes in Reproductive Behaviors in Thai Sarus Crane, Black-headed Ibis, and Lesser Adjutant Stork. Zoolog Sci 2013; 30:1070-80. [DOI: 10.2108/zsj.30.1070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Apfelbeck B, Mortega K, Kiefer S, Kipper S, Vellema M, Villavicencio CP, Gahr M, Goymann W. Associated and disassociated patterns in hormones, song, behavior and brain receptor expression between life-cycle stages in male black redstarts, Phoenicurus ochruros. Gen Comp Endocrinol 2013; 184:93-102. [PMID: 23337030 DOI: 10.1016/j.ygcen.2012.11.027] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/06/2012] [Revised: 10/24/2012] [Accepted: 11/22/2012] [Indexed: 12/22/2022]
Abstract
Testosterone has been suggested to be involved in the regulation of male territorial behavior. For example, seasonal peaks in testosterone typically coincide with periods of intense competition between males for territories and mating partners. However, some species also express territorial behavior outside a breeding context when testosterone levels are low and, thus, the degree to which testosterone facilitates territorial behavior in these species is not well understood. We studied territorial behavior and its neuroendocrine correlates in male black redstarts. Black redstarts defend territories in spring during the breeding period, but also in the fall outside a reproductive context when testosterone levels are low. In the present study we assessed if song output and structure remain stable across life-cycle stages. Furthermore, we assessed if brain anatomy may give insight into the role of testosterone in the regulation of territorial behavior in black redstarts. We found that males sang spontaneously at a high rate during the nonbreeding period when testosterone levels were low; however the trill-like components of spontaneously produced song contained less repetitive elements during nonbreeding than during breeding. This higher number of repetitive elements in trills did not, however, correlate with a larger song control nucleus HVC during breeding. However, males expressed more aromatase mRNA in the preoptic area - a brain nucleus important for sexual and aggressive behavior - during breeding than during nonbreeding. In combination with our previous studies on black redstarts our results suggest that territorial behavior in this species only partly depends on sex steroids: spontaneous song output, seasonal variation in trills and non-vocal territorial behavior in response to a simulated territorial intruder seem to be independent of sex steroids. However, context-dependent song during breeding may be facilitated by testosterone - potentially by conversion of testosterone to estradiol in the preoptic area.
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Affiliation(s)
- Beate Apfelbeck
- Abteilung für Verhaltensneurobiologie, Max-Planck-Institut für Ornithologie, Seewiesen, Germany.
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Rodgers CMC, Neff BD, Knapp R. Androgen-mediated nurturing and aggressive behaviors during paternal care in bluegill sunfish (Lepomis macrochirus). Horm Behav 2013; 63:454-61. [PMID: 23268781 DOI: 10.1016/j.yhbeh.2012.12.008] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/04/2012] [Revised: 12/14/2012] [Accepted: 12/16/2012] [Indexed: 11/17/2022]
Abstract
Male parental care in vertebrates often involves both defensive and nurturing behaviors. Whether androgens differentially mediate these two types of behaviors, or a trade-off exists between them, has been studied by behavioral endocrinologists for years but predominantly in species with biparental care. In such systems, potential detrimental effects of elevated androgens on parental care behaviors are often compensated for by changes in behavior of the unmanipulated parent. In contrast, for species where only one parent provides care, manipulation of androgen levels may more clearly determine if there are differential effects of androgens on these two types of behaviors and whether the proposed trade-off between defensive and nurturing behavior exists. Here, we manipulated androgen levels in two ways in bluegill sunfish (Lepomis macrochirus), a species where males provide sole parental care for the young. At the onset of the care period, males were implanted with 11-ketotestosterone, a major teleost androgen, the androgen receptor antagonist flutamide, or a blank implant. A separate control group experienced no manipulation. Males were then observed over several days and tested for their aggressiveness towards an experimentally-presented brood predator and for nurturing behavior (fanning of the eggs, removal of dead or fungal-infected eggs). Males implanted with 11-ketotestosterone displayed 64% more aggressive behaviors and 71% fewer nurturing behaviors than control groups. In contrast, males implanted with flutamide displayed 7% fewer aggressive behaviors and 126% more nurturing behaviors than control males. Taken together, these results show that aggression and nurturing behaviors are mediated by androgens and suggest that there is a trade-off between the two behaviors during parental care in this species.
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Affiliation(s)
- Chandra M C Rodgers
- Department of Biology, Western University, 1151 Richmond Street N, London, Ontario, Canada N6A 5B7.
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Apfelbeck B, Mortega KG, Kiefer S, Kipper S, Goymann W. Life-history and hormonal control of aggression in black redstarts: Blocking testosterone does not decrease territorial aggression, but changes the emphasis of vocal behaviours during simulated territorial intrusions. Front Zool 2013; 10:8. [PMID: 23433033 PMCID: PMC3636094 DOI: 10.1186/1742-9994-10-8] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2012] [Accepted: 01/31/2013] [Indexed: 01/09/2023] Open
Abstract
INTRODUCTION Many studies in behavioural endocrinology attempt to link territorial aggression with testosterone, but the exact relationship between testosterone and territorial behaviour is still unclear and may depend on the ecology of a species. The degree to which testosterone facilitates territorial behaviour is particularly little understood in species that defend territories during breeding and outside the breeding season, when plasma levels of testosterone are low. Here we suggest that species that defend territories in contexts other than reproduction may have lost the direct regulation of territorial behaviour by androgens even during the breeding season. In such species, only those components of breeding territoriality that function simultaneously as sexually selected signals may be under control of sex steroids. RESULTS We investigated black redstarts (Phoenicurus ochruros), a species that shows periods of territoriality within and outside of the breeding season. We treated territorial males with an anti-androgen and an aromatase inhibitor during the breeding season to block both the direct and indirect effects of testosterone. Three and ten days after the treatment, implanted males were challenged with a simulated territorial intrusion. The treatment did not reduce the overall territorial response, but it changed the emphasis of territoriality: experimental males invested more in behaviours addressed directly towards the intruder, whereas placebo-treated males put most effort into their vocal response, a component of territoriality that may be primarily directed towards their mating partner rather than the male opponent. CONCLUSIONS In combination with previous findings, these data suggest that overall territoriality may be decoupled from testosterone in male black redstarts. However, high levels of testosterone during breeding may facilitate-context dependent changes in song.
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Affiliation(s)
- Beate Apfelbeck
- Abteilung für Verhaltensneurobiologie, Max-Planck-Institut für Ornithologie, Eberhard-Gwinner-Str, 6a, Seewiesen, D-82319, Germany.
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