1
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Betancourth-Cundar M, Canoine V, Fusani L, Cadena CD. Does testosterone underly the interplay between male traits and territorial behavior in neotropical poison frogs? Horm Behav 2024; 162:105547. [PMID: 38677262 DOI: 10.1016/j.yhbeh.2024.105547] [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: 08/21/2023] [Revised: 02/24/2024] [Accepted: 04/12/2024] [Indexed: 04/29/2024]
Abstract
The ability of individual animals to defend a territory as well as various phenotypic and behavioral traits may be targets of sexual selection used by males to evaluate their competitors or by females to choose males. A frequent question in animal behavior is whether male traits and characteristics of their territory are correlated and what are the mechanisms that may mediate such associations when they exist. Because hormones link phenotype to behavior, by studying the role of testosterone in territoriality one may come closer to understanding the mechanisms mediating correlations or lack thereof between characteristics of territories and of males. We evaluated whether variation in characteristics of territories (size and quality) are correlated with variation in morphology, coloration, testosterone, heterozygosity, and calls in two species of poison frogs. The Amazonian frog Allobates aff. trilineatus exhibits male care and defends territories only during the breeding season, while the endangered frog Oophaga lehmanni displays maternal care and defends territories throughout the year. We found that morphological traits (body length, weight, thigh size), call activity, and testosterone levels correlated with size and various indicators of quality of the territory. However, the direction of these correlations (whether positive or negative) and which specific morphological, acoustic traits or testosterone level variables covaried depended on the species. Our findings highlight an endocrine pathway as part of the physiological machinery that may underlie the interplay between male traits and territorial behavior. We were able to identify some male traits related to territory attributes, but whether females choose males based on these traits requires further research.
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Affiliation(s)
| | - Virginie Canoine
- Department of Behavioral and Cognitive Biology, University of Vienna, Vienna, Austria
| | - Leonida Fusani
- Konrad Lorenz Institute of Ethology, University of Veterinary Medicine, Vienna, Austria
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2
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Dantzer B. Frank Beach Award Winner: The centrality of the hypothalamic-pituitary-adrenal axis in dealing with environmental change across temporal scales. Horm Behav 2023; 150:105311. [PMID: 36707334 DOI: 10.1016/j.yhbeh.2023.105311] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/09/2022] [Revised: 01/02/2023] [Accepted: 01/06/2023] [Indexed: 01/26/2023]
Abstract
Understanding if and how individuals and populations cope with environmental change is an enduring question in evolutionary ecology that has renewed importance given the pace of change in the Anthropocene. Two evolutionary strategies of coping with environmental change may be particularly important in rapidly changing environments: adaptive phenotypic plasticity and/or bet hedging. Adaptive plasticity could enable individuals to match their phenotypes to the expected environment if there is an accurate cue predicting the selective environment. Diversifying bet hedging involves the production of seemingly random phenotypes in an unpredictable environment, some of which may be adaptive. Here, I review the central role of the hypothalamic-pituitary-adrenal (HPA) axis and glucocorticoids (GCs) in enabling vertebrates to cope with environmental change through adaptive plasticity and bet hedging. I first describe how the HPA axis mediates three types of adaptive plasticity to cope with environmental change (evasion, tolerance, recovery) over short timescales (e.g., 1-3 generations) before discussing how the implications of GCs on phenotype integration may depend upon the timescale under consideration. GCs can promote adaptive phenotypic integration, but their effects on phenotypic co-variation could also limit the dimensions of phenotypic space explored by animals over longer timescales. Finally, I discuss how organismal responses to environmental stressors can act as a bet hedging mechanism and therefore enhance evolvability by increasing genetic or phenotypic variability or reducing patterns of genetic and phenotypic co-variance. Together, this emphasizes the crucial role of the HPA axis in understanding fundamental questions in evolutionary ecology.
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Affiliation(s)
- Ben Dantzer
- Department of Psychology, University of Michigan, MI 48109 Ann Arbor, MI, USA; Department of Ecology and Evolutionary Biology, University of Michigan, MI 48109, Ann Arbor, MI, USA.
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3
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Rodríguez C, Fusani L, Raboisson G, Hödl W, Ringler E, Canoine V. Androgen responsiveness to simulated territorial intrusions in Allobates femoralis males: Evidence supporting the challenge hypothesis in a territorial frog. Gen Comp Endocrinol 2022; 326:114046. [PMID: 35472315 DOI: 10.1016/j.ygcen.2022.114046] [Citation(s) in RCA: 3] [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: 11/04/2021] [Revised: 04/20/2022] [Accepted: 04/21/2022] [Indexed: 11/18/2022]
Abstract
Territoriality has been widely described across many animal taxa, where the acquisition and defence of a territory are critical for the fitness of an individual. Extensive evidence suggests that androgens are involved in the modulation of territorial behaviours in male vertebrates. Short-term increase of androgen following a territorial encounter appears to favour the outcome of a challenge. The "Challenge Hypothesis" proposed by Wingfield and colleagues outlines the existence of a positive feedback relationship between androgen and social challenges (e.g., territorial intrusions) in male vertebrates. Here we tested the challenge hypothesis in the highly territorial poison frog, Allobates femoralis, in its natural habitat by exposing males to simulated territorial intrusions in the form of acoustic playbacks. We quantified repeatedly androgen concentrations of individual males via a non-invasive water-borne sampling approach. Our results show that A. femoralis males exhibited a positive behavioural and androgenic response after being confronted to simulated territorial intrusions, providing support for the Challenge Hypothesis in a territorial frog.
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Affiliation(s)
- Camilo Rodríguez
- Department of Behavioral and Cognitive Biology, University of Vienna, Djerassiplatz 1, 1030 Vienna, Austria.
| | - Leonida Fusani
- Department of Behavioral and Cognitive Biology, University of Vienna, Djerassiplatz 1, 1030 Vienna, Austria; Konrad Lorenz Institute of Ethology, University of Veterinary Medicine, Vienna, Austria
| | - Gaëlle Raboisson
- Department of Behavioral and Cognitive Biology, University of Vienna, Djerassiplatz 1, 1030 Vienna, Austria
| | - Walter Hödl
- Department of Behavioral and Cognitive Biology, University of Vienna, Djerassiplatz 1, 1030 Vienna, Austria
| | - Eva Ringler
- Department of Behavioral and Cognitive Biology, University of Vienna, Djerassiplatz 1, 1030 Vienna, Austria; Messerli Research Institute, University of Veterinary Medicine Vienna, Medical University Vienna, University of Vienna, Vienna, Austria; Division of Behavioural Ecology, Institute of Ecology and Evolution, University of Bern, Bern, Switzerland
| | - Virginie Canoine
- Department of Behavioral and Cognitive Biology, University of Vienna, Djerassiplatz 1, 1030 Vienna, Austria
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4
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BeVier GT, Ayton C, Brock KM. It ain’t easy being orange: lizard colour morphs occupying highly vegetated microhabitats suffer greater ectoparasitism. AMPHIBIA-REPTILIA 2022. [DOI: 10.1163/15685381-bja10097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Abstract
Intraspecific colour morphs usually differ in more traits than just colour. These traits can manifest as differences in morph physiology, behaviour, and ecology. Ecological differences among colour morphs, such as the degree of parasitism, can influence the evolution, maintenance, and loss of morphs from populations. High ectoparasite load can directly and deleteriously impact host fitness, and thus could influence colour morph persistence in populations if certain morphs are more frequently exposed to parasites or are more susceptible to parasitism. The Aegean wall lizard, Podarcis erhardii, is a colour polymorphic island lizard that is parasitized externally by ticks and mites. These ectoparasites can affect aspects of host lizard behaviour and physiology – including thermoregulation and body mass – and therefore are an important factor influencing the ecology and fitness of P. erhardii. We find that among sympatric colour morphs, ectoparasite loads differ; namely, monochromatic orange morphs have the highest numbers of ectoparasites, and in general, morphs with orange alleles (orange, orange-white, and orange-yellow) are more heavily parasitized by ticks and mites than the other morphs. Our results indicate that morphs with orange alleles tend to occupy microhabitats with significantly more vegetation cover and thus may increase their exposure to ticks and mites. Ecological differences between morphs could be an important factor contributing to demonstrated patterns of orange morph rarity and loss in P. erhardii populations.
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Affiliation(s)
| | - Cole Ayton
- Department of Life and Environmental Science, School of Natural Sciences, University of California, Merced, CA 95343, USA
| | - Kinsey M. Brock
- Department of Environmental Science, Policy, and Management, College of Natural Resources, University of California, Berkeley, CA 94720, USA
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5
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Abstract
AbstractTrade-offs and constraints are inherent to life, and studies of these phenomena play a central role in both organismal and evolutionary biology. Trade-offs can be defined, categorized, and studied in at least six, not mutually exclusive, ways. (1) Allocation constraints are caused by a limited resource (e.g., energy, time, space, essential nutrients), such that increasing allocation to one component necessarily requires a decrease in another (if only two components are involved, this is referred to as the Y-model, e.g., energy devoted to size versus number of offspring). (2) Functional conflicts occur when features that enhance performance of one task decrease performance of another (e.g., relative lengths of in-levers and out-levers, force-velocity trade-offs related to muscle fiber type composition). (3) Shared biochemical pathways, often involving integrator molecules (e.g., hormones, neurotransmitters, transcription factors), can simultaneously affect multiple traits, with some effects being beneficial for one or more components of Darwinian fitness (e.g., survival, age at first reproduction, fecundity) and others detrimental. (4) Antagonistic pleiotropy describes genetic variants that increase one component of fitness (or a lower-level trait) while simultaneously decreasing another. (5) Ecological circumstances (or selective regime) may impose trade-offs, such as when foraging behavior increases energy availability yet also decreases survival. (6) Sexual selection may lead to the elaboration of (usually male) secondary sexual characters that improve mating success but handicap survival and/or impose energetic costs that reduce other fitness components. Empirical studies of trade-offs often search for negative correlations between two traits that are the expected outcomes of the trade-offs, but this will generally be inadequate if more than two traits are involved and especially for complex physiological networks of interacting traits. Moreover, trade-offs often occur only in populations that are experiencing harsh environmental conditions or energetic challenges at the extremes of phenotypic distributions, such as among individuals or species that have exceptional athletic abilities. Trade-offs may be (partially) circumvented through various compensatory mechanisms, depending on the timescale involved, ranging from acute to evolutionary. Going forward, a pluralistic view of trade-offs and constraints, combined with integrative analyses that cross levels of biological organization and traditional boundaries among disciplines, will enhance the study of evolutionary organismal biology.
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6
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Hinchcliffe DL, Lea JMD, Palme R, Shultz S. Fecal Glucocorticoid Metabolites as Biomarkers in Equids: Assay Choice Matters. J Wildl Manage 2021. [DOI: 10.1002/jwmg.22066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
| | - Jessica M. D. Lea
- School of Earth and Environmental Sciences University of Manchester United Kingdom
| | - Rupert Palme
- Department of Biomedical Sciences University of Veterinary Medicine Vienna Austria
| | - Susanne Shultz
- School of Earth and Environmental Sciences University of Manchester United Kingdom
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7
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Alaasam VJ, Keehn JE, Durso AM, French SS, Feldman CR. Ectoparasite Load Is Reduced in Side-Blotched Lizards ( Uta stansburiana) at Wind Farms: Implications for Oxidative Stress. Physiol Biochem Zool 2021; 94:35-49. [PMID: 33296296 DOI: 10.1086/712100] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
AbstractWind-generated power is one of the fastest growing alternative energy strategies worldwide and will likely account for 20% of US energy production by 2030. The installation and maintenance of wind farms are associated with increased human activity and can generate noise pollution, disturb and fragment habitat, and even alter community composition and structure. These environmental and ecological changes can increase physiological stress for vertebrates and affect important life-history attributes, such as immune function. However, little is known about how wind farms influence physiology and disease or parasite resistance in nonvolant wildlife. Here, we test the notion that renewable wind farms increase physiological stress and correlated aspects of disease resistance (parasite load) in a common desert vertebrate, the side-blotched lizard (Uta stansburiana). We captured lizards from three wind farms and three undisturbed reference sites in the San Gorgonio Pass wind resource area in the Mojave Desert, California. We quantified individual external parasite loads and measured plasma antioxidant capacity and concentrations of reactive oxygen metabolites as a combined metric of oxidative stress. Contrary to our expectations, individuals at wind farm sites had significantly fewer external parasites than at undeveloped sites. Additionally, we found a slight positive correlation between parasite load and oxidative stress for individuals at wind farm sites but not at reference sites. Our results demonstrate a complex, potentially context-dependent relationship between stress physiology and disease resistance for lizards in anthropogenically disturbed environments. Understanding how wind farms affect the physiology and ecoimmunology of terrestrial fauna is necessary to mitigate the ecological costs of alternative energy development.
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8
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Noble DWA, Kar F, Nakagawa S, Keogh JS, Whiting MJ. Sexual selection on performance traits in an Australian lizard with alternative reproductive tactics. J Evol Biol 2020; 34:451-464. [PMID: 33296538 DOI: 10.1111/jeb.13752] [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: 06/27/2020] [Revised: 11/29/2020] [Accepted: 12/01/2020] [Indexed: 11/30/2022]
Abstract
Sexual selection shapes the adaptive landscape in complex ways that lead to trait integration. Much of our understanding of selection comes from studies of morphological traits. However, few studies attempt to quantify the form and direction of selection on performance even though it is predicted to be a more direct target of selection in nature. We measured sexual selection on performance traits (bite force, sprint speed and endurance) in an Australian lizard, the Eastern water skink (Eulamprus quoyii). We first staged 123 contests between size-matched males to investigate whether performance traits were important in determining contest outcome. In a second experiment, we established six breeding populations in large replicate semi-natural enclosures to estimate whether performance traits predicted reproductive success. Our results show that none of the performance measures were important in predicting contest outcome and were not generally strong predictors of reproductive success. However, our analyses suggest a complex fitness landscape driven by males adopting different alternative reproductive tactics (ARTs). We provide a rare test of the role performance plays in sexual selection and highlight the need to test common assumptions regarding the link between maximal performance and fitness. Our results suggest that performance traits may not necessarily be direct targets of sexual selection, but rather indirect targets through their integration with morphological and/or behavioural traits, highlighting a need for more explicit tests of the predicted links between performance and fitness.
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Affiliation(s)
- Daniel W A Noble
- Department of Biological Sciences, Macquarie University, Sydney, NSW, Australia.,School of Biological, Earth and Environmental Sciences, Ecology and Evolution Research Centre, University of New South Wales, Sydney, NSW, Australia.,Division of Ecology and Evolution, Research School of Biology, The Australian National University, Canberra, ACT, Australia
| | - Fonti Kar
- School of Biological, Earth and Environmental Sciences, Ecology and Evolution Research Centre, University of New South Wales, Sydney, NSW, Australia
| | - Shinichi Nakagawa
- School of Biological, Earth and Environmental Sciences, Ecology and Evolution Research Centre, University of New South Wales, Sydney, NSW, Australia
| | - J Scott Keogh
- Division of Ecology and Evolution, Research School of Biology, The Australian National University, Canberra, ACT, Australia
| | - Martin J Whiting
- Department of Biological Sciences, Macquarie University, Sydney, NSW, Australia
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9
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Maney DL, Merritt JR, Prichard MR, Horton BM, Yi SV. Inside the supergene of the bird with four sexes. Horm Behav 2020; 126:104850. [PMID: 32937166 PMCID: PMC7725849 DOI: 10.1016/j.yhbeh.2020.104850] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Revised: 09/04/2020] [Accepted: 09/06/2020] [Indexed: 02/07/2023]
Abstract
The white-throated sparrow (Zonotrichia albicollis) offers unique opportunities to understand the adaptive value of supergenes, particularly their role in alternative phenotypes. In this species, alternative plumage morphs segregate with a nonrecombining segment of chromosome 2, which has been called a 'supergene'. The species mates disassortatively with respect to the supergene; that is, each breeding pair consists of one individual with it and one without it. This species has therefore been called the "bird with four sexes". The supergene segregates with a behavioral phenotype; birds with it are more aggressive and less parental than birds without it. Here, we review our efforts to identify the genes inside the supergene that are responsible for the behavioral polymorphism. The gene ESR1, which encodes estrogen receptor α, differs between the morphs and predicts both territorial and parental behavior. Variation in the regulatory regions of ESR1 causes an imbalance in expression of the two alleles, and the degree to which this imbalance favors the supergene allele predicts territorial singing. In heterozygotes, knockdown of ESR1 causes a phenotypic switch, from more aggressive to less aggressive. We recently showed that another gene important for social behavior, vasoactive intestinal peptide (VIP), is differentially expressed between the morphs and predicts territorial singing. We hypothesize that ESR1 and VIP contribute to behavior in a coordinated way and could represent co-adapted alleles. Because the supergene contains more than 1000 individual genes, this species provides rich possibilities for discovering alleles that work together to mediate life-history trade-offs and maximize the fitness of alternative complex phenotypes.
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Affiliation(s)
- Donna L Maney
- Department of Psychology, Emory University, Atlanta, GA, USA.
| | | | | | - Brent M Horton
- Department of Biology, Millersville University, Millersville, PA, USA
| | - Soojin V Yi
- School of Biological Sciences, Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA, USA
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10
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Fresnillo B, Belliure J, Gil D, Cuervo JJ. Hormonal control of seasonal color change in female spiny-footed lizards: an observational and experimental approach. Curr Zool 2019; 65:633-642. [PMID: 31857810 PMCID: PMC6911850 DOI: 10.1093/cz/zoz012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2018] [Accepted: 03/25/2019] [Indexed: 11/12/2022] Open
Abstract
Breeding coloration of females often signals aspects of their reproductive status, suggesting a link between color and sex steroid hormones. In this study, we examined the relationships between 2 sex steroid hormones (progesterone and β-estradiol) and reproductive coloration in female spiny-footed lizards Acanthodactylus erythrurus. We first explored natural variation in female plasma hormone levels and coloration during their reproductive cycle. β-estradiol was negatively related to brightness and positively related to red saturation, whereas progesterone was not significantly related to coloration. After identifying key relationships, plasma hormone concentrations were manipulated by creating 3 experimental female groups (β-estradiol-treated, progesterone-treated, and control), and the effects on coloration were monitored. β-estradiol-treated females, in which there was a rise in both β-estradiol and progesterone levels, lost their red coloration earlier than females in the other 2 experimental groups, whereas progesterone treatment had no significant effect on female coloration. Our results suggest that high levels of either β-estradiol alone or β-estradiol together with progesterone trigger the loss of red coloration in female spiny-footed lizards, and that progesterone alone does not affect coloration. We hypothesize that changes in female breeding color might be regulated by β-estradiol in species in which conspicuous coloration is displayed before ovulation, and by progesterone in species in which this color is displayed during gravidity.
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Affiliation(s)
- Belén Fresnillo
- Department of Life Sciences, Ecology Section, University of Alcalá, Madrid, Spain
- Department of Functional and Evolutionary Ecology, Estación Experimental de Zonas Áridas (CSIC), Carretera de Sacramento s/n, Almería, Spain
| | - Josabel Belliure
- Department of Life Sciences, Ecology Section, University of Alcalá, Madrid, Spain
| | - Diego Gil
- Department of Evolutionary Ecology, Museo Nacional de Ciencias Naturales (CSIC), Madrid, Spain
| | - José J Cuervo
- Department of Evolutionary Ecology, Museo Nacional de Ciencias Naturales (CSIC), Madrid, Spain
- Address correspondence to José J. Cuervo. E-mail:
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11
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Han CS, Jablonski PG. Alternative reproductive tactics shape within-species variation in behavioral syndromes. Behav Ecol 2019. [DOI: 10.1093/beheco/arz068] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
AbstractMultiple behaviors can correlate with each other at the individual level (behavioral syndrome), and behavioral syndromes can vary in their direction between populations within a species. Within-species variation in behavioral syndromes is predicted to be associated with alternative reproductive tactics (ARTs), which evolve under different selection regimes. Here, we tested this using a water strider species, Gerris gracilicornis, in which males employ 2 ARTs that are fixed for life: signaling males (producing courtship ripples) versus nonsignaling males (producing no courtship ripples). We measured multiple behaviors in males with both of these ARTs and compared behavioral syndromes between them. Our results showed that signaling males were more active and attempted to mate more frequently than nonsignaling males. This shaped an overall behavioral syndrome between activities in mating and nonmating contexts when we pooled both ARTs. In addition, the behavioral syndromes between cautiousness and mating activity differed significantly between ARTs. In signaling males, the syndrome was significantly negative: signaling males more eager to mate tended to leave their refuges more rapidly. However, mating activity and cautiousness were not correlated in nonsignaling males. This might be because active males, in the context of predation risk and mating, were favored during the evolution and maintenance of the unique intimidating courtship tactic of G. gracilicornis males. Thus, our findings suggest that ARTs facilitate behavioral divergence and also contribute to the evolution of tactic-specific behavioral syndromes. We also show that research on ARTs and behavioral syndromes can be harmonized to study behavioral variation.
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Affiliation(s)
- Chang S Han
- Department of Biology, Kyung Hee University, Dongdaemun-Gu, Seoul, Korea
| | - Piotr G Jablonski
- Laboratory of Behavioral Ecology and Evolution, School of Biological Sciences, Seoul National University, Gwanak-gu, Seoul, Korea
- Museum and Institute of Zoology, Polish Academy of Sciences, Wilcza, Warsaw, Poland
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12
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Hazard LC, Nagy KA, Miles DB, Svensson EI, Costa D, Sinervo B. Integration of Genotype, Physiological Performance, and Survival in a Lizard (Uta stansburiana) with Alternative Mating Strategies. Physiol Biochem Zool 2019; 92:303-315. [DOI: 10.1086/703136] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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13
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Bruinjé AC, Moura MO, Maggi BS, São-Pedro VA, Pessoa DM, Costa GC. Conspecifics of the Striped Lava Lizard are able to distinguish sex and male colour morphs in apparently homogeneous dull dorsal colouration. AMPHIBIA-REPTILIA 2019. [DOI: 10.1163/15685381-20181048] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Abstract
Animal colouration plays a key role in inter and intraspecific interactions, pre-eminently in mate signalling. When multiple types of colouration occur within sexes it is possible that they show alternative reproductive strategies. In lizards, most colouration studies do not incorporate how colour is perceived by conspecifics. Here, we used unbiased colour analysis methods (spectrophotometry and visual modelling) to test for sexual dimorphism and within male dichromatism in the Striped Lava Lizard. We found that males express two distinct colourations that are different from females in several dorsal and ventral body regions. Our results showed UV reflection at the throat, an important body region for signalling. Ventral patches, the coloured badge seen in adult males of Tropidurus spp., have two distinct colour classes within males (Y and B males). Morphs are best discriminated by blue and yellow chroma, and brightness. Body size had little influence on colouration, suggesting that colour may be linked to inheritance rather than growth. Our study clearly shows sexual dichromatism and the existence of colour morphs in this species. Moreover, morph differences in colouration are perceptible by conspecifics. These differences are not only between ventral patches, but also in other body parts such as the dorsum, previously considered as cryptic by human observers. We suggest that colouration at the ventral patches and throat might play a role in intraspecific interactions. Patches increase colour intensity during breeding season and are likely to be costly by pigment-based expression, whereas throat’s UV reflection might have a cost infringed by conspicuousness.
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Affiliation(s)
- Andre C. Bruinjé
- 1Graduate Program in Ecology and Conservation Biology, Department of Zoology, Universidade Federal do Paraná, Curitiba, Paraná, Brazil
- 2Laboratory of Biogeography, Macroecology and Evolutionary Biology, Universidade Federal do Rio Grande do Norte, Natal, Rio Grande do Norte, Brazil
| | - Mauricio O. Moura
- 1Graduate Program in Ecology and Conservation Biology, Department of Zoology, Universidade Federal do Paraná, Curitiba, Paraná, Brazil
| | - Bruno S. Maggi
- 2Laboratory of Biogeography, Macroecology and Evolutionary Biology, Universidade Federal do Rio Grande do Norte, Natal, Rio Grande do Norte, Brazil
| | - Vinicius A. São-Pedro
- 3Laboratory of Sensory Ecology, Department of Physiology, Universidade Federal do Rio Grande do Norte, Natal, Rio Grande do Norte, Brazil
- 4Centro de Ciências da Natureza, Universidade Federal de São Carlos, Campus Lagoa do Sino, Buri, São Paulo, Brazil
| | - Daniel M.A. Pessoa
- 3Laboratory of Sensory Ecology, Department of Physiology, Universidade Federal do Rio Grande do Norte, Natal, Rio Grande do Norte, Brazil
| | - Gabriel C. Costa
- 5Department of Biology, Auburn University at Montgomery, Montgomery, AL 36124, USA
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14
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Schell CJ, Young JK, Lonsdorf EV, Santymire RM, Mateo JM. Parental habituation to human disturbance over time reduces fear of humans in coyote offspring. Ecol Evol 2018; 8:12965-12980. [PMID: 30619597 PMCID: PMC6308887 DOI: 10.1002/ece3.4741] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2018] [Revised: 10/10/2018] [Accepted: 10/24/2018] [Indexed: 12/18/2022] Open
Abstract
A fundamental tenet of maternal effects assumes that maternal variance over time should have discordant consequences for offspring traits across litters. Yet, seldom are parents observed across multiple reproductive bouts, with few studies considering anthropogenic disturbances as an ecological driver of maternal effects. We observed captive coyote (Canis latrans) pairs over two successive litters to determine whether among‐litter differences in behavior (i.e., risk‐taking) and hormones (i.e., cortisol and testosterone) corresponded with parental plasticity in habituation. Thus, we explicitly test the hypothesis that accumulating experiences of anthropogenic disturbance reduces parental fear across reproductive bouts, which should have disparate phenotypic consequences for first‐ and second‐litter offspring. To quantify risk‐taking behavior, we used foraging assays from 5–15 weeks of age with a human observer present as a proxy for human disturbance. At 5, 10, and 15 weeks of age, we collected shaved hair to quantify pup hormone levels. We then used a quantitative genetic approach to estimate heritability, repeatability, and between‐trait correlations. We found that parents were riskier (i.e., foraged more frequently) with their second versus first litters, supporting our prediction that parents become increasingly habituated over time. Second‐litter pups were also less risk‐averse than their first‐litter siblings. Heritability for all traits did not differ from zero (0.001–0.018); however, we found moderate support for repeatability in all observed traits (r = 0.085–0.421). Lastly, we found evidence of positive phenotypic and cohort correlations among pup traits, implying that cohort identity (i.e., common environment) contributes to the development of phenotypic syndromes in coyote pups. Our results suggest that parental habituation may be an ecological cue for offspring to reduce their fear response, thus emphasizing the role of parental plasticity in shaping their pups’ behavioral and hormonal responses toward humans.
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Affiliation(s)
- Christopher J Schell
- Committee on Evolutionary Biology University of Chicago Chicago Illinois.,School of Interdisciplinary Arts and Sciences University of Washington Tacoma Tacoma Washington
| | - Julie K Young
- USDA-WS-NWRC Predator Research Facility, Department of Wildland Resources Utah State University Logan Utah
| | | | - Rachel M Santymire
- Committee on Evolutionary Biology University of Chicago Chicago Illinois.,Conservation and Science Department Lincoln Park Zoo Chicago Illinois
| | - Jill M Mateo
- Committee on Evolutionary Biology University of Chicago Chicago Illinois
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15
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Wolf TE, Schaebs FS, Bennett NC, Burroughs R, Ganswindt A. Age and socially related changes in fecal androgen metabolite concentrations in free-ranging male giraffes. Gen Comp Endocrinol 2018; 255:19-25. [PMID: 28978410 DOI: 10.1016/j.ygcen.2017.09.028] [Citation(s) in RCA: 13] [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: 05/24/2017] [Revised: 09/19/2017] [Accepted: 09/30/2017] [Indexed: 11/26/2022]
Abstract
In many mammal species, androgen levels in males are elevated during periods of mating activity, often to facilitate aggressive behavior between males over access to fertile females. However, this pattern might be less obvious in species with a rather low male-male aggression rate, or in those that are not strictly seasonal breeders. A complex social structure, as well as additional social and environmental factors, might add more to the complexity. Here, we applied a non-invasive method to monitor fecal androgen metabolite (fAM) levels in free-ranging giraffe bulls over a period of months to examine longitudinal patterns of androgen metabolite concentrations in relation to observed male sexual behavior in different age classes. Giraffes are non-seasonal breeders, living in a fission-fusion social system and males show a roaming strategy to search for fertile females. Our results show that season has an impact on fAM levels in free-ranging giraffes, with respective steroid concentrations being higher in summer. In the presence of females, fAM levels of bulls are significantly higher compared to when found in all-male groups, with old adult bulls showing the highest fAM levels. In contrast, young adult bulls have overall slightly higher fAM levels compared to old adult bulls when residing in all male groups. Sexual behavior increases fAM levels only in old adult bulls.
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Affiliation(s)
- T E Wolf
- Endocrine Research Laboratory, Department of Anatomy and Physiology, Faculty of Veterinary Science, University of Pretoria, Onderstepoort 0110, South Africa; Department of Animal, Wildlife and Grassland Sciences, Faculty of Natural and Agricultural Sciences, University of the Free State, Bloemfontein 9300, South Africa.
| | - F S Schaebs
- Max Planck Institute for Evolutionary Anthropology, Deutscher Platz 6, Leipzig, Germany
| | - N C Bennett
- Mammal Research Institute, Department of Zoology and Entomology, Faculty of Natural and Agricultural Sciences, University of Pretoria, Pretoria 0028, South Africa
| | - R Burroughs
- Centre of Veterinary Wildlife Studies, Faculty of Veterinary Science, University of Pretoria, Onderstepoort 0110, South Africa
| | - A Ganswindt
- Endocrine Research Laboratory, Department of Anatomy and Physiology, Faculty of Veterinary Science, University of Pretoria, Onderstepoort 0110, South Africa; Mammal Research Institute, Department of Zoology and Entomology, Faculty of Natural and Agricultural Sciences, University of Pretoria, Pretoria 0028, South Africa
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16
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Behavioral and physiological polymorphism in males of the austral lizard Liolaemus sarmientoi. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2017; 204:219-230. [DOI: 10.1007/s00359-017-1233-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2017] [Revised: 11/15/2017] [Accepted: 11/23/2017] [Indexed: 12/18/2022]
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17
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Jaworski KE, Lattanzio MS. Physiological Consequences of Food Limitation for a Color Polymorphic Lizard: Are Coping Responses Morph-Specific? COPEIA 2017. [DOI: 10.1643/cp-17-597] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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18
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Lea JMD, Walker SL, Kerley GIH, Jackson J, Matevich SC, Shultz S. Non‐invasive physiological markers demonstrate link between habitat quality, adult sex ratio and poor population growth rate in a vulnerable species, the Cape mountain zebra. Funct Ecol 2017. [DOI: 10.1111/1365-2435.13000] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Jessica M. D. Lea
- School of Earth and Environmental SciencesUniversity of Manchester Manchester UK
- North of England Zoological SocietyChester Zoo Upton‐by‐Chester UK
| | - Susan L. Walker
- North of England Zoological SocietyChester Zoo Upton‐by‐Chester UK
| | - Graham I. H. Kerley
- Centre for African Conservation EcologyNelson Mandela University Port Elizabeth South Africa
| | - John Jackson
- Department of Animal and Plant SciencesUniversity of Sheffield Sheffield UK
| | | | - Susanne Shultz
- School of Earth and Environmental SciencesUniversity of Manchester Manchester UK
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19
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Ezenwa VO, Snider MH. Reciprocal relationships between behaviour and parasites suggest that negative feedback may drive flexibility in male reproductive behaviour. Proc Biol Sci 2017; 283:rspb.2016.0423. [PMID: 27194703 DOI: 10.1098/rspb.2016.0423] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2016] [Accepted: 04/22/2016] [Indexed: 12/21/2022] Open
Abstract
Parasites are ubiquitous components of the environment that contribute to behavioural and life-history variation among hosts. Although it is well known that host behaviour can affect parasite infection risk and that parasites can alter host behaviour, the potential for dynamic feedback between these processes is poorly characterized. Using Grant's gazelle (Nanger granti) as a model, we tested for reciprocal effects of behaviour on parasites and parasites on behaviour to understand whether behaviour-parasite feedback could play a role in maintaining variation in male reproductive behaviour. Adult male gazelles either defend territories to attract mates or reside in bachelor groups. Territoriality is highly variable both within- and between-individuals, suggesting that territory maintenance is costly. Using a combination of longitudinal and experimental studies, we found that individual males transition frequently between territorial and bachelor reproductive status, and that elevated parasite burdens are a cost of territoriality. Moreover, among territorial males, parasites suppress aspects of behaviour related to territory maintenance and defence. These results suggest that territorial behaviour promotes the accumulation of parasites in males, and these parasites dampen the very behaviours required for territory maintenance. Our findings suggest that reciprocal feedback between host behaviour and parasitism could be a mechanism maintaining variation in male reproductive behaviour in the system.
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Affiliation(s)
- Vanessa O Ezenwa
- Odum School of Ecology and Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, GA, USA
| | - Matthew H Snider
- Odum School of Ecology and Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, GA, USA
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20
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Golubović A, Anđelković M, Arsovski D, Bonnet X, Tomović L. Locomotor performances reflect habitat constraints in an armoured species. Behav Ecol Sociobiol 2017. [DOI: 10.1007/s00265-017-2318-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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21
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The peacock train does not handicap cursorial locomotor performance. Sci Rep 2016; 6:36512. [PMID: 27805067 PMCID: PMC5090354 DOI: 10.1038/srep36512] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Accepted: 10/13/2016] [Indexed: 11/17/2022] Open
Abstract
Exaggerated traits, like the peacock train, are recognized as classic examples of sexual selection. The evolution of sexual traits is often considered paradoxical as, although they enhance reproductive success, they are widely presumed to hinder movement and survival. Many exaggerated traits represent an additional mechanical load that must be carried by the animal and therefore may influence the metabolic cost of locomotion and constrain locomotor performance. Here we conducted respirometry experiments on peacocks and demonstrate that the exaggerated sexually selected train does not compromise locomotor performance in terms of the metabolic cost of locomotion and its kinematics. Indeed, peacocks with trains had a lower absolute and mass specific metabolic cost of locomotion. Our findings suggest that adaptations that mitigate any costs associated with exaggerated morphology are central in the evolution of sexually selected traits.
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22
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Herrel A, Lopez-Darias M, Vanhooydonck B, Cornette R, Kohlsdorf T, Brandt R. Do Adult Phenotypes Reflect Selection on Juvenile Performance? A Comparative Study on Performance and Morphology in Lizards. Integr Comp Biol 2016; 56:469-78. [DOI: 10.1093/icb/icw010] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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23
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Schell CJ, Young JK, Lonsdorf EV, Mateo JM, Santymire RM. Olfactory attractants and parity affect prenatal androgens and territoriality of coyote breeding pairs. Physiol Behav 2016; 165:43-54. [PMID: 27378509 DOI: 10.1016/j.physbeh.2016.06.038] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2016] [Revised: 06/23/2016] [Accepted: 06/30/2016] [Indexed: 01/28/2023]
Abstract
Hormones are fundamental mediators of personality traits intimately linked with reproductive success. Hence, alterations to endocrine factors may dramatically affect individual behavior that has subsequent fitness consequences. Yet it is unclear how hormonal or behavioral traits change with environmental stressors or over multiple reproductive opportunities, particularly for biparental fauna. To simulate an environmental stressor, we exposed captive coyote (Canis latrans) pairs to novel coyote odor attractants (i.e. commercial scent lures) mid-gestation to influence territorial behaviors, fecal glucocorticoid (FGMs) and fecal androgen metabolites (FAMs). In addition, we observed coyote pairs as first-time and experienced breeders to assess the influence of parity on our measures. Treatment pairs received the odors four times over a 20-day period, while control pairs received water. Odor-treated pairs scent-marked (e.g. urinated, ground scratched) and investigated odors more frequently than control pairs, and had higher FAMs when odors were provided. Pairs had higher FAMs as first-time versus experienced breeders, indicating that parity also affected androgen production during gestation. Moreover, repeatability in scent-marking behaviors corresponded with FGMs and FAMs, implying that coyote territoriality during gestation is underpinned by individually-specific hormone profiles. Our results suggest coyote androgens during gestation are sensitive to conspecific olfactory stimuli and prior breeding experience. Consequently, fluctuations in social or other environmental stimuli as well as increasing parity may acutely affect coyote traits essential to reproductive success.
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Affiliation(s)
- Christopher J Schell
- Committee on Evolutionary Biology, University of Chicago, 1025 E. 57th Street, Culver Hall 402, Chicago, IL 60637, United States.
| | - Julie K Young
- USDA-WS-NWRC, Predator Research Facility, Department of Wildland Resources, Utah State University, USU - BNR 163, Logan, UT 84322, United States
| | - Elizabeth V Lonsdorf
- Department of Psychology, Franklin and Marshall College, P.O. Box 3003, Lancaster, PA 17603, United States
| | - Jill M Mateo
- Committee on Evolutionary Biology, University of Chicago, 1025 E. 57th Street, Culver Hall 402, Chicago, IL 60637, United States
| | - Rachel M Santymire
- Committee on Evolutionary Biology, University of Chicago, 1025 E. 57th Street, Culver Hall 402, Chicago, IL 60637, United States; Department of Conservation and Science, Lincoln Park Zoo, 2001 N. Clark St., Chicago, IL 60614, United States
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24
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Lattanzio MS, Miles DB. Trophic niche divergence among colour morphs that exhibit alternative mating tactics. ROYAL SOCIETY OPEN SCIENCE 2016; 3:150531. [PMID: 27152203 PMCID: PMC4852626 DOI: 10.1098/rsos.150531] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2015] [Accepted: 03/15/2016] [Indexed: 05/03/2023]
Abstract
Discrete colour morphs associated with alternative mating tactics are assumed to be ecologically equivalent. Yet suites of behaviours linked with reproduction can also favour habitat segregation and exploitation of different prey among morphs. By contrast, trophic polymorphisms are usually attributed to morphs exhibiting habitat or prey selectivity. An alternative hypothesis is that habitat variation generates a trophic polymorphism driven by differences in morph reproductive behaviour, the spatial dispersion of morphs in a landscape and their exposure to different prey types. In this scenario, morphs are allowed to vary in habitat or diet selectivity (e.g. specialist or generalist) as they do in behaviour, rather than being assumed to exhibit equivalent levels of ecological specialization. We test this hypothesis using male Urosaurus ornatus lizards that exhibit a discrete dewlap colour polymorphism that reflects alternative mating tactics. We found blue morphs specialize on prey at higher trophic levels, yellow males display plasticity in trophic and morphological attributes and orange males are trophic generalists. Our results also demonstrate that morph diet differences are enhanced in resource-limited habitats. We conclude that discrete behavioural morphs may also diverge in morphology and trophic niche. Jointly, these processes may enhance speciation rates in colour polymorphic taxa.
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25
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Hau M, Casagrande S, Ouyang J, Baugh A. Glucocorticoid-Mediated Phenotypes in Vertebrates. ADVANCES IN THE STUDY OF BEHAVIOR 2016. [DOI: 10.1016/bs.asb.2016.01.002] [Citation(s) in RCA: 107] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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26
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Yewers MSC, Pryke S, Stuart-Fox D. Behavioural differences across contexts may indicate morph-specific strategies in the lizard Ctenophorus decresii. Anim Behav 2016. [DOI: 10.1016/j.anbehav.2015.10.029] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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27
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Husak JF. Measuring Selection on Physiology in the Wild and Manipulating Phenotypes (in Terrestrial Nonhuman Vertebrates). Compr Physiol 2015; 6:63-85. [PMID: 26756627 DOI: 10.1002/cphy.c140061] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
To understand why organisms function the way that they do, we must understand how evolution shapes physiology. This requires knowledge of how selection acts on physiological traits in nature. Selection studies in the wild allow us to determine how variation in physiology causes variation in fitness, revealing how evolution molds physiology over evolutionary time. Manipulating phenotypes experimentally in a selection study shifts the distribution of trait variation in a population to better explore potential constraints and the adaptive value of physiological traits. There is a large database of selection studies in the wild on a variety of traits, but very few of those are physiological traits. Nevertheless, data available so far suggest that physiological traits, including metabolic rate, thermal physiology, whole-organism performance, and hormone levels, are commonly subjected to directional selection in nature, with stabilizing and disruptive selection less common than predicted if physiological traits are optimized to an environment. Selection studies on manipulated phenotypes, including circulating testosterone and glucocorticoid levels, reinforce this notion, but reveal that trade-offs between survival and reproduction or correlational selection can constrain the evolution of physiology. More studies of selection on physiological traits in nature that quantify multiple traits are necessary to better determine the manner in which physiological traits evolve and whether different types of traits (dynamic performance vs. regulatory) evolve differently.
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Affiliation(s)
- Jerry F Husak
- Department of Biology, University of St. Thomas, St. Paul, Minnesota, USA
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28
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Ahmadivand S, Farahmand H, Mirvaghefi A, Eagderi S, Zargar A. Effects of (Anti) Androgenic Endocrine Disruptors (DEHP and Butachlor) on Immunoglobulin M (IgM) and Leukocytes Counts of Male Rainbow Trout (Oncorhynchus mykiss). BULLETIN OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 2015; 94:695-700. [PMID: 25708297 DOI: 10.1007/s00128-015-1503-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2014] [Accepted: 02/14/2015] [Indexed: 06/04/2023]
Abstract
The effect of two anti-androgenic endocrine disrupting compounds, i.e. the plasticizer di (2-ethylhexyl) phthalate (DEHP) and herbicide butachlor, were evaluated for their effects on immunoglobulin M (IgM) and leukocytes in male rainbow trout. Also, plasma testosterone (T) concentration was measured to confirm their anti-androgenic effects. In the first experiment, trout were treated with 50 mg/kg (body weight) DEHP intraperitoneally, and in the second one, fish were exposed to 0.39 mg/L butachlor for 10 days. The results showed that T concentrations and white blood cells were significantly lower in fish exposed to either DEHP or butachlor compared to control fish (p < 0.05). Fish showed significantly elevated neutrophil levels and decreased lymphocyte levels in the butachlor (p < 0.05); however, no significant difference was observed in lymphocyte and neutrophils values in the DEHP treatment (p > 0.05). In addition, no significant differences were found in IgM, eosinophil and monocyte parameters in either DEHP or butachlor treatments (p > 0.05). These results confirmed that leukocytes counts can be considered as a novel marker of immunotoxicity triggered by (anti) androgenic endocrine disruptors.
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Affiliation(s)
- Sohrab Ahmadivand
- Department of Aquatic Animal Health, Faculty of Veterinary Medicine, University of Tehran, P.O. Box: 14155-6453, Tehran, Iran,
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29
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Maney DL, Horton BM, Zinzow-Kramer WM. Estrogen Receptor Alpha as a Mediator of Life-History Trade-offs. Integr Comp Biol 2015; 55:323-31. [PMID: 25855477 DOI: 10.1093/icb/icv005] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Trade-offs between competitive and parental strategies often are mediated by sex steroids. The mechanisms underlying steroid signaling and metabolism may therefore serve as targets of disruptive selection that leads to alternative behavioral phenotypes. White-throated sparrows exhibit two color morphs that differ in both competitive and parental behavior; white-striped (WS) birds engage in more territorial singing, whereas tan-striped (TS) birds provision nestlings more often. Although WS birds have higher levels of plasma testosterone (T) and estradiol than do TS birds, experimental equalization of these hormones does not abolish morph differences in singing. Neural sensitivity to sex steroids may differ between the morphs because the gene for estrogen receptor alpha (ERα) has been captured by a chromosomal rearrangement found only in the WS birds. We recently showed that expression of this gene differs between the morphs and may drive the behavioral polymorphism. First, the ERα promoter region contains fixed polymorphisms that affect transcription efficiency in vitro. Second, in a free-living population, local expression of ERα depends strongly on morph and predicts both territorial singing and parental provisioning. Differential ERα expression is particularly striking in the medial amygdala; WS birds have three times more ERα mRNA than do TS birds. This difference persists during the non-breeding season and is unaffected by exogenous T treatment. Finally, preliminary data generated by RNA-seq confirm that ERα expression in MeA is both differentially expressed and correlated with territorial singing. Together, these results suggest that ERα may be a target of disruptive selection that leads to alternative behavioral strategies. Our future directions include a more detailed analysis of the ERα promoter regions to determine the molecular basis of differential expression as well as gene network analyses to identify genes connected to ERα.
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Affiliation(s)
- Donna L Maney
- Department of Psychology, Emory University, Atlanta, GA 30322, USA
| | - Brent M Horton
- Department of Psychology, Emory University, Atlanta, GA 30322, USA
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30
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Hebets EA, Hansen M, Jones TC, Wilgers DJ. Octopamine levels relate to male mating tactic expression in the wolf spider Rabidosa punctulata. Anim Behav 2015. [DOI: 10.1016/j.anbehav.2014.11.023] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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31
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Lailvaux SP, Husak JF. The life history of whole-organism performance. QUARTERLY REVIEW OF BIOLOGY 2015; 89:285-318. [PMID: 25510077 DOI: 10.1086/678567] [Citation(s) in RCA: 95] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
For almost 40 years, studies of whole-organism performance have formed a cornerstone of evolutionary physiology. Although its utility as a heuristic guide is beyond question, and we have learned much about morphological evolution from its application, the ecomorphological paradigm has frequently been applied to performance evolution in ways that range from unsatisfactory to inappropriate. More importantly, the standard ecomorphological paradigm does not account for tradeoffs among performance and other traits, nor between performance traits that are mediated by resource allocation. A revised paradigm that includes such tradeoffs, and the possible ways that performance and fitness-enhancing traits might affect each other, could potentially revivify the study of phenotypic evolution and make important inroads into understanding the relationships between morphology and performance and between performance and Darwinian fitness. We describe such a paradigm, and discuss the various ways that performance and key life-history traits might interact with and affect each other. We emphasize both the proximate mechanisms potentially linking such traits, and the likely ultimate factors driving those linkages, as well as the evolutionary implications for the overall, multivariate phenotype. Finally, we highlight several research directions that will shed light on the evolution and ecology of whole-organism performance and related life-history traits.
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32
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Kolluru GR, Walz J, Hanninen AF, Downey K, Kalbach B, Gupta S, Earley RL. Exploring behavioral and hormonal flexibility across light environments in guppies from low-predation populations. BEHAVIOUR 2015. [DOI: 10.1163/1568539x-00003264] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Phenotypic flexibility is essential for organisms to respond to changing environments. Guppies experience light environments that alter their visibility to conspecifics and predators. We used guppies from populations with low rates of predation by fish, but which may be subject to avian predators, to test the hypotheses that conspicuous behaviors and the androgens that mediate them are reduced under high light, and that cortisol levels are increased under high light because the perceived risk is stressful. We found reduced courtship, potentially driven by the reduced female response to courtship, under high light. Aggression and testosterone levels were higher in the absence of females. We found elevated androgen and decreased cortisol levels following social interactions, but no relationship between hormones and behavior, and no influence of light level on hormones. We forward explanations for these results and advocate understanding the flexible response to light environments in a range of guppy populations.
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Affiliation(s)
- Gita R. Kolluru
- aBiological Sciences Department, California Polytechnic State University, San Luis Obispo, CA 93407, USA
| | - Julia Walz
- aBiological Sciences Department, California Polytechnic State University, San Luis Obispo, CA 93407, USA
| | - Amanda F. Hanninen
- bDepartment of Biological Sciences, University of Alabama, Tuscaloosa, AL, USA
- cDepartment of Biology, University of Virginia, Charlottesville, VA, USA
| | - Kate Downey
- aBiological Sciences Department, California Polytechnic State University, San Luis Obispo, CA 93407, USA
| | - Brandy Kalbach
- aBiological Sciences Department, California Polytechnic State University, San Luis Obispo, CA 93407, USA
| | - Shelly Gupta
- aBiological Sciences Department, California Polytechnic State University, San Luis Obispo, CA 93407, USA
| | - Ryan L. Earley
- bDepartment of Biological Sciences, University of Alabama, Tuscaloosa, AL, USA
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33
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Blank DA, Ruckstuhl K, Yang W. Seasonal dynamics of agonistic displays in territorial and non-territorial males of goitered gazelle. ZOOLOGY 2014; 118:63-8. [PMID: 25435489 DOI: 10.1016/j.zool.2014.08.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2014] [Revised: 08/28/2014] [Accepted: 08/30/2014] [Indexed: 11/25/2022]
Abstract
Aggression serves a great variety of social functions, one of which is protection of individual territories from intruders. Territorial males of many antelope species show aggressive noncontact displays, and only rarely fight. It has been suggested that ungulate males tend to have more frequent and longer aggressive interactions with rivals of similar age or social status than with males of dissimilar status. In the present paper, we test whether territorial and non-territorial males behave in a similar manner and avoid fights, and whether or not they preferentially direct aggressive and longer agonistic interactions towards males of similar age or social status, rather than towards other classes of males. We found that territorial males usually avoided straight fights with peers, and instead mainly used noncontact displays in aggressive interactions. In contrast, non-territorial males used fights considerably more often, especially during the onset of territoriality in April to May, when these males had their most frequent aggressive interactions. Territorial bucks aggressively interacted most frequently with non-territorial males and significantly less often with other territorial males, but agonistic noncontact displays between territorial males lasted the longest. In contrast, non-territorial males addressed their aggressive noncontact displays and fights most often to peers and less frequently to sub-adults. Asymmetry in the social status of territorial vs. non-territorial males was likely responsible for the distinctively different agonistic behaviors shown by the two types of males, which in turn are likely due to the different costs and benefits each male can accrue from these aggressive interactions.
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Affiliation(s)
- D A Blank
- Key Laboratory of Biogeography and Bioresource in Arid Land, Xinjiang Institute of Ecology and Geography, The Chinese Academy of Sciences, 818 South Beijing Road, Urumqi 830011, China; Institute of Zoology, Kazakh Academy of Sciences, Alma-Ata 050060, Kazakhstan
| | - K Ruckstuhl
- Department of Biological Sciences, University Calgary, 2500 University Drive N.W., Calgary, AB T2N 1N4, Canada
| | - W Yang
- Key Laboratory of Biogeography and Bioresource in Arid Land, Xinjiang Institute of Ecology and Geography, The Chinese Academy of Sciences, 818 South Beijing Road, Urumqi 830011, China.
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34
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Lattanzio MS, Miles DB. Ecological divergence among colour morphs mediated by changes in spatial network structure associated with disturbance. J Anim Ecol 2014; 83:1490-500. [DOI: 10.1111/1365-2656.12252] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2013] [Accepted: 05/20/2014] [Indexed: 11/27/2022]
Affiliation(s)
- Matthew S. Lattanzio
- Department of Biological Sciences; Ohio University; 107 Irvine Hall Athens OH 45701 USA
| | - Donald B. Miles
- Department of Biological Sciences; Ohio University; 107 Irvine Hall Athens OH 45701 USA
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35
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Bastiaans E, Bastiaans MJ, Morinaga G, Castañeda Gaytán JG, Marshall JC, Bane B, de la Cruz FM, Sinervo B. Female preference for sympatric vs. allopatric male throat color morphs in the mesquite lizard (Sceloporus grammicus) species complex. PLoS One 2014; 9:e93197. [PMID: 24718297 PMCID: PMC3981705 DOI: 10.1371/journal.pone.0093197] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2013] [Accepted: 03/03/2014] [Indexed: 12/29/2022] Open
Abstract
Color polymorphic sexual signals are often associated with alternative reproductive behaviors within populations, and the number, frequency, or type of morphs present often vary among populations. When these differences lead to assortative mating by population, the study of such polymorphic taxa may shed light on speciation mechanisms. We studied two populations of a lizard with polymorphic throat color, an important sexual signal. Males in one population exhibit orange, yellow, or blue throats; whereas males in the other exhibit orange, yellow, or white throats. We assessed female behavior when choosing between allopatric and sympatric males. We asked whether females discriminated more when the allopatric male was of an unfamiliar morph than when the allopatric male was similar in coloration to the sympatric male. We found that female rejection of allopatric males relative to sympatric males was more pronounced when males in a pair were more different in throat color. Our findings may help illuminate how behavioral responses to color morph differences between populations with polymorphic sexual signals contribute to reproductive isolation.
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Affiliation(s)
- Elizabeth Bastiaans
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, California, United States of America
| | - Mary Jane Bastiaans
- Nanooptical Materials, Incorporated, Carson, California, United States of America
| | - Gen Morinaga
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, California, United States of America
| | | | - Jonathon C. Marshall
- Department of Zoology, Weber State University, Ogden, Utah, United States of America
| | - Brendan Bane
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, California, United States of America
| | - Fausto Méndez de la Cruz
- Laboratorio de Herpetología, Departamento de Zoología, Instituto de Biología, Universidad Nacional Autónoma de México, Distrito Federal, México
| | - Barry Sinervo
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, California, United States of America
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Noble DWA, Fanson KV, Whiting MJ. Sex, androgens, and whole-organism performance in an Australian lizard. Biol J Linn Soc Lond 2014. [DOI: 10.1111/bij.12252] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Daniel W. A. Noble
- Department of Biological Sciences; Macquarie University; Sydney NSW 2109 Australia
| | - Kerry V. Fanson
- Department of Biological Sciences; Macquarie University; Sydney NSW 2109 Australia
- School of Life and Environmental Sciences; Deakin University; Geelong VIC 3216 Australia
| | - Martin J. Whiting
- Department of Biological Sciences; Macquarie University; Sydney NSW 2109 Australia
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Noble DWA, Wechmann K, Keogh JS, Whiting MJ. Behavioral and Morphological Traits Interact to Promote the Evolution of Alternative Reproductive Tactics in a Lizard. Am Nat 2013; 182:726-42. [DOI: 10.1086/673535] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Schultner J, Kitaysky AS, Gabrielsen GW, Hatch SA, Bech C. Differential reproductive responses to stress reveal the role of life-history strategies within a species. Proc Biol Sci 2013; 280:20132090. [PMID: 24089339 DOI: 10.1098/rspb.2013.2090] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Life-history strategies describe that 'slow'- in contrast to 'fast'-living species allocate resources cautiously towards reproduction to enhance survival. Recent evidence suggests that variation in strategies exists not only among species but also among populations of the same species. Here, we examined the effect of experimentally induced stress on resource allocation of breeding seabirds in two populations with contrasting life-history strategies: slow-living Pacific and fast-living Atlantic black-legged kittiwakes. We tested the hypothesis that reproductive responses in kittiwakes under stress reflect their life-history strategies. We predicted that in response to stress, Pacific kittiwakes reduce investment in reproduction compared with Atlantic kittiwakes. We exposed chick-rearing kittiwakes to a short-term (3-day) period of increased exogenous corticosterone (CORT), a hormone that is released during food shortages. We examined changes in baseline CORT levels, parental care and effects on offspring. We found that kittiwakes from the two populations invested differently in offspring when facing stress. In response to elevated CORT, Pacific kittiwakes reduced nest attendance and deserted offspring more readily than Atlantic kittiwakes. We observed lower chick growth, a higher stress response in offspring and lower reproductive success in response to CORT implantation in Pacific kittiwakes, whereas the opposite occurred in the Atlantic. Our findings support the hypothesis that life-history strategies predict short-term responses of individuals to stress within a species. We conclude that behaviour and physiology under stress are consistent with trade-off priorities as predicted by life-history theory. We encourage future studies to consider the pivotal role of life-history strategies when interpreting inter-population differences of animal responses to stressful environmental events.
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Affiliation(s)
- J Schultner
- Department of Biology, Norwegian University of Science and Technology, , Trondheim, Norway, Institute of Arctic Biology, University of Alaska Fairbanks, , Fairbanks, AK, USA, Norwegian Polar Institute, , Tromsø, Norway, US Geological Survey, Anchorage Science Center, , Anchorage, AK, USA, Institute for Seabird Research and Conservation, , Anchorage, AK, USA
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39
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Lozano GA, Lank DB, Addison B. Immune and oxidative stress trade-offs in four classes of Ruffs (Philomachus pugnax) with different reproductive strategies. CAN J ZOOL 2013. [DOI: 10.1139/cjz-2012-0324] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Immunity and resistance to oxidative stress are two mechanistically related aspects of self-maintenance that are usually not studied together in connection to ecological or evolutionary relevant variables. Whereas many studies compare two sexes, here we use Ruffs (Philomachus pugnax (L., 1758)), a species in which males have three alternative reproductive morphs: independents, satellites, and faeders. Previous work suggested that immune function in Ruffs depends on energetic constraints or potential of injuries. Based on their behaviour and life history, the three male morphs and females can be placed on an ordinal scale with independents at one end and females at the other, and these two explanations predict opposite patterns along this continuum. Innate and cell-mediated immunity decreased along this axis from independents to females, supporting a risk-of-injury explanation over the energetic constrains hypothesis. No such pattern was evident for oxidative stress or resistance, and no relationship was detected between immunity and oxidative resistance or stress. Hence, during the breeding season immunity reflected the risk of injury, with faeders located in the immunological continuum between females and other male morphs. Species with alternative reproductive strategies provide particularly useful systems in which to address the evolution and ecology behind physiological mechanisms.
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Affiliation(s)
- George A. Lozano
- Department of Biological Sciences, Simon Fraser University, Burnaby, BC V5A 1S6, Canada
| | - David B. Lank
- Department of Biological Sciences, Simon Fraser University, Burnaby, BC V5A 1S6, Canada
| | - Brianne Addison
- Department of Biological Sciences, Simon Fraser University, Burnaby, BC V5A 1S6, Canada
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40
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van Breukelen NA. Androgen receptor antagonist impairs courtship but not aggressive behavior in the monogamous cichlid, Amatitlania nigrofasciata. Horm Behav 2013; 63:527-32. [PMID: 23380161 DOI: 10.1016/j.yhbeh.2013.01.008] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/03/2012] [Revised: 01/15/2013] [Accepted: 01/21/2013] [Indexed: 11/16/2022]
Abstract
Androgens, specifically 11-ketotestosterone, are hypothesized to be important in the expression of pre-spawning behaviors such as courtship and aggression in many teleost species. This experiment attempted to elucidate the roles of androgens in the expression of pre-spawning courtship and aggression in male convict cichlids (Amatitlania nigrofasciata). In a laboratory experiment, males were treated with either the androgen receptor antagonist flutamide or blank control and subsequently exposed to social conditions to stimulate inter-sexual courtship or intra-sexual aggression. Males treated with flutamide expressed significantly fewer courtship behaviors than control males but did not differ from control males in pre-spawning intra-sexual aggression. In a field experiment, males treated with flutamide expressed significantly less courtship behavior than males given blank capsules or unmanipulated control males, but did not differ from either set of control males in aggression towards conspecifics or overall aggression to con- and heterospecifics. These data suggest that androgens mediate pre-spawning courtship behavior but not pre-spawning aggression in this species.
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Affiliation(s)
- Natalie April van Breukelen
- Mount Aloysius College, Dept. of Science and Mathematics, 7373 Admiral Peary Highway, Cresson, PA 16630, USA.
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41
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Meylan S, Richard M, Bauer S, Haussy C, Miles D. Costs of Mounting an Immune Response during Pregnancy in a Lizard. Physiol Biochem Zool 2013; 86:127-36. [DOI: 10.1086/668637] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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42
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Crespi EJ, Williams TD, Jessop TS, Delehanty B. Life history and the ecology of stress: how do glucocorticoid hormones influence life-history variation in animals? Funct Ecol 2012. [DOI: 10.1111/1365-2435.12009] [Citation(s) in RCA: 269] [Impact Index Per Article: 22.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Erica J. Crespi
- School of Biological Sciences; Washington State University; Box 644236; Pullman; Washington; USA
| | - Tony D. Williams
- Department of Biological Sciences; Simon Fraser University; Burnaby; British Columbia; V5A 1S6; Canada
| | - Tim S. Jessop
- Department of Zoology; University of Melbourne; Melbourne; Victoria; 3010; Australia
| | - Brendan Delehanty
- Department of Biological Sciences; Centre for the Neurobiology of Stress; University of Toronto Scarborough; Toronto; Ontario; M1C 1A4; Canada
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Meylan S, Miles DB, Clobert J. Hormonally mediated maternal effects, individual strategy and global change. Philos Trans R Soc Lond B Biol Sci 2012; 367:1647-64. [PMID: 22566673 DOI: 10.1098/rstb.2012.0020] [Citation(s) in RCA: 85] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
A challenge to ecologists and evolutionary biologists is predicting organismal responses to the anticipated changes to global ecosystems through climate change. Most evidence suggests that short-term global change may involve increasing occurrences of extreme events, therefore the immediate response of individuals will be determined by physiological capacities and life-history adaptations to cope with extreme environmental conditions. Here, we consider the role of hormones and maternal effects in determining the persistence of species in altered environments. Hormones, specifically steroids, are critical for patterning the behaviour and morphology of parents and their offspring. Hence, steroids have a pervasive influence on multiple aspects of the offspring phenotype over its lifespan. Stress hormones, e.g. glucocorticoids, modulate and perturb phenotypes both early in development and later into adulthood. Females exposed to abiotic stressors during reproduction may alter the phenotypes by manipulation of hormones to the embryos. Thus, hormone-mediated maternal effects, which generate phenotypic plasticity, may be one avenue for coping with global change. Variation in exposure to hormones during development influences both the propensity to disperse, which alters metapopulation dynamics, and population dynamics, by affecting either recruitment to the population or subsequent life-history characteristics of the offspring. We suggest that hormones may be an informative index to the potential for populations to adapt to changing environments.
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Affiliation(s)
- Sandrine Meylan
- Laboratoire Ecologie-Evolution, CNRS UMR 7625, Université Pierre et Marie Curie-Paris 6, 7 quai Saint Bernard, 75252 Paris cedex 05, France
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Martínez-Méndez N, Mejía O, Rocha-Gómez A, Méndez-De La Cruz FR. Morphological convergence and molecular divergence: the taxonomic status ofSceloporus serrifer(squamata, phrynosomatidae) subspecies. ZOOL SCR 2012. [DOI: 10.1111/j.1463-6409.2011.00509.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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45
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Ezenwa VO, Stefan Ekernas L, Creel S. Unravelling complex associations between testosterone and parasite infection in the wild. Funct Ecol 2011. [DOI: 10.1111/j.1365-2435.2011.01919.x] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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46
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Alabarse PV, Salomon TB, Medeiros TM, Hackenhaar FS, Schüller AK, Ehrenbrink G, Benfato MS. Oxidative stress in the kidney of reproductive male rats during aging. Exp Gerontol 2011; 46:773-80. [DOI: 10.1016/j.exger.2011.05.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2010] [Revised: 04/06/2011] [Accepted: 05/12/2011] [Indexed: 01/05/2023]
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47
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Mouttham L, Buhr M, Freeman E, Widowski T, Graham L, Brown J. Interrelationship of serum testosterone, dominance and ovarian cyclicity status in female African elephants. Anim Reprod Sci 2011; 126:115-21. [DOI: 10.1016/j.anireprosci.2011.04.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2011] [Revised: 04/04/2011] [Accepted: 04/14/2011] [Indexed: 10/18/2022]
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48
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Ventura T, Manor R, Aflalo ED, Weil S, Khalaila I, Rosen O, Sagi A. Expression of an Androgenic Gland-Specific Insulin-Like Peptide during the Course of Prawn Sexual and Morphotypic Differentiation. ISRN ENDOCRINOLOGY 2011; 2011:476283. [PMID: 22363879 PMCID: PMC3262648 DOI: 10.5402/2011/476283] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/04/2011] [Accepted: 02/16/2011] [Indexed: 11/26/2022]
Abstract
The crustacean male-specific androgenic gland (AG) regulates sexual differentiation. In the prawn Macrobrachium rosenbergii, silencing an AG-specific insulin-like encoding transcript (Mr-IAG) inhibited the development of male sexual characters, suggesting that Mr-IAG is a key androgenic hormone. We used recombinant pro-Mr-IAG peptide to generate antibodies that recognized the peptide in AG cells and extracts, as verified by mass spectrometry. We revealed the temporal expression pattern of Mr-IAG and studied its relevance to the timetable of sex differentiation processes in juveniles and after puberty. Mr-IAG was expressed from as early as 20 days after metamorphosis, prior to the appearance of external male sexual characters. Mr-IAG expression was lower in the less reproductively active orange-clawed males than in both the dominant blue-clawed males and the actively sneak mating small males. These results suggest a role for Mr-IAG both in the timing of male sexual differentiation and in regulating reproductive strategies.
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Affiliation(s)
- Tomer Ventura
- Department of Life Sciences, Ben-Gurion University of the Negev, P.O. Box 653, Beer Sheva 84105, Israel
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49
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Alabarse PVG, Hackenhaar FS, Medeiros TM, Mendes MFA, Viacava PR, Schüller ÁK, Salomon TB, Ehrenbrink G, Benfato MS. Oxidative stress in the brain of reproductive male rats during aging. Exp Gerontol 2011; 46:241-8. [DOI: 10.1016/j.exger.2010.10.009] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2010] [Revised: 08/26/2010] [Accepted: 10/13/2010] [Indexed: 12/31/2022]
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50
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Maney DL, Goodson JL. Neurogenomic mechanisms of aggression in songbirds. ADVANCES IN GENETICS 2011; 75:83-119. [PMID: 22078478 DOI: 10.1016/b978-0-12-380858-5.00002-2] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Our understanding of the biological basis of aggression in all vertebrates, including humans, has been built largely upon discoveries first made in birds. A voluminous literature now indicates that hormonal mechanisms are shared between humans and a number of avian species. Research on genetics mechanisms in birds has lagged behind the more typical laboratory species because the necessary tools have been lacking until recently. Over the past 30 years, three major technical advances have propelled forward our understanding of the hormonal, neural, and genetic bases of aggression in birds: (1) the development of assays to measure plasma levels of hormones in free-living individuals, or "field endocrinology"; (2) the immunohistochemical labeling of immediate early gene products to map neural responses to social stimuli; and (3) the sequencing of the zebra finch genome, which makes available a tremendous set of genomic tools for studying gene sequences, expression, and chromosomal structure in species for which we already have large datasets on aggressive behavior. This combination of hormonal, neuroendocrine, and genetic tools has established songbirds as powerful models for understanding the neural basis and evolution of aggression in vertebrates. In this chapter, we discuss the contributions of field endocrinology toward a theoretical framework linking aggression with sex steroids, explore evidence that the neural substrates of aggression are conserved across vertebrate species, and describe a promising new songbird model for studying the molecular genetic mechanisms underlying aggression.
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Affiliation(s)
- Donna L Maney
- Department of Psychology, Emory University, Atlanta, Georgia, USA
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