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Megía-Palma R, Paranjpe D, Cooper RD, Blaimont P, Sinervo B. Natural parasites in conjunction with behavioral and color traits explain male agonistic behaviors in a lizard. Curr Zool 2024; 70:59-69. [PMID: 38476133 PMCID: PMC10926264 DOI: 10.1093/cz/zoac095] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2022] [Accepted: 11/19/2022] [Indexed: 03/14/2024] Open
Abstract
Male competition conforms to a cost-benefit model, because while aggression may increase reproductive prospects, it can also increase the risk of injury. We hypothesize that an additional cost in aggressive males would be an increase in parasite load associated with a high energy investment into sexual competition. Some of these infections, in turn, may downmodulate the level of host aggression via energetic trade-offs. We staged dyadic male contests in the lab to investigate the relationships of multiple parasites with the agonistic behavior of lizard hosts, Sceloporus occidentalis. We also included both color and behavioral traits from opponents in the analyses because (1) color patches of lizards may serve as intraspecific signals used by conspecifics to assess the quality of opponents, and (2) contests between male lizards fit classical models of escalated aggression, where lizards increase aggression displays in response to an opponent's behavior. The results conform to our hypothesis because male lizards displayed more pushups when they had more ticks. Moreover, some parasites may modulate the levels of aggression because lizards infected by hematic coccidians performed fewer pushups. Interestingly, lizards also displayed fewer pushups when both the chroma and size of the opponent's blue patch were greater. The results thus also supported the role of the blue patch of S. occidentalis as a sexual armament, because it contributed to the deterrence of aggression from opponent lizards. We revealed that natural parasitic infections in lizard hosts can contribute to their agonistic behavior. We encourage future studies to account for parasites in behavioral tests with lizards.
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Affiliation(s)
- Rodrigo Megía-Palma
- Department of Biomedicine and Biotechnology, Parasitology Unit, Universidad de Alcalá (UAH), E-28805, Alcalá de Henares, Spain
- CIBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, InBIO Laboratório Associado, Campus de Vairão, Universidade do Porto, P-4485-661 Vairão, Portugal
- BIOPOLIS Program in Genomics, Biodiversity and Land Planning, CIBIO, Campus de Vairão, P-4485-661 Vairão, Portugal
| | - Dhanashree Paranjpe
- Rupa Rahul Bajaj Center for Environment and Art, Empress Botanical Gardens, Kavade Mala, Pune, India
| | - Robert D Cooper
- Department of Ecology and Evolutionary Biology, University of California, Los Angeles, CA 90095, USA
| | - Pauline Blaimont
- Department of Biology, University of Houston Downtown, 1 Main St., Houston, TX 77002, USA
| | - Barry Sinervo
- Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, CA 95064, USA
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2
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Assis BA, Avery JD, Earley RL, Langkilde T. Masculinized Sexual Ornaments in Female Lizards Correlate with Ornament-Enhancing Thermoregulatory Behavior. Integr Org Biol 2022; 4:obac029. [PMID: 36034057 PMCID: PMC9409079 DOI: 10.1093/iob/obac029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
The adaptive significance of colorful or exaggerated traits (i.e., ornaments) expressed in females is often unclear. Competing hypotheses suggest that expression of female ornaments arises from maladaptive (or neutral) genetic inheritance from males along with incomplete epigenetic regulation, or from positive selection for ornaments in females under social competition. Whether costly or advantageous, the visibility of such traits can sometimes be behaviorally modulated in order to maximize fitness. Female eastern fence lizards express blue badges that are variable in size and color saturation. These are rudimentary compared to those seen in males and carry important costs such as reduced mating opportunities. Body temperature is a well-established enhancer of badge color, and thus thermoregulation may be one way these animals modulate badge visibility. We quantified realized body temperatures of female lizards paired in laboratory trials and observed that females with larger badges attained higher body temperatures when freely allowed to thermoregulate, sometimes beyond physiological optima. In this association between phenotype and behavior, females with larger badges exhibited thermoregulatory patterns that increase their badges’ visibility. This signal-enhancing behavior is difficult to reconcile with the widely held view that female ornaments are maladaptive, suggesting they may carry context-dependent social benefits.
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Affiliation(s)
- B A Assis
- Department of Biology, Intercollege Graduate Degree Program in Ecology, The Pennsylvania State University , University Park, PA 16802
| | - J D Avery
- Department of Ecosystem Science and Management, Intercollege Graduate Degree Program in Ecology, Pennsylvania State University , University Park, PA 16802
| | - R L Earley
- Department of Biological Sciences, University of Alabama , Tuscaloosa, AL 35487
| | - T Langkilde
- Department of Biology, Intercollege Graduate Degree Program in Ecology, The Pennsylvania State University , University Park, PA 16802
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3
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Assis BA, Avery JD, Earley RL, Langkilde T. Fitness Costs of Maternal Ornaments and Prenatal Corticosterone Manifest as Reduced Offspring Survival and Sexual Ornament Expression. Front Endocrinol (Lausanne) 2022; 13:801834. [PMID: 35311233 PMCID: PMC8928773 DOI: 10.3389/fendo.2022.801834] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Accepted: 02/01/2022] [Indexed: 12/01/2022] Open
Abstract
Colorful traits (i.e., ornaments) that signal quality have well-established relationships with individual condition and physiology. Furthermore, ornaments expressed in females may have indirect fitness effects in offspring via the prenatal physiology associated with, and social consequences of, these signaling traits. Here we examine the influence of prenatal maternal physiology and phenotype on condition-dependent signals of their offspring in adulthood. Specifically, we explore how prenatal maternal testosterone, corticosterone, and ornament color and size correlate with female and male offspring survival to adulthood and ornament quality in the lizard Sceloporus undulatus. Offspring of females with more saturated badges and high prenatal corticosterone were less likely to survive to maturity. Badge saturation and area were negatively correlated between mothers and their male offspring, and uncorrelated to those in female offspring. Maternal prenatal corticosterone was correlated negatively with badge saturation of male offspring in adulthood. Our results indicate that maternal ornamentation and prenatal concentrations of a stress-relevant hormone can lead to compounding fitness costs by reducing offspring survival to maturity and impairing expression of a signal of quality in surviving males. This mechanism may occur in concert with social costs of ornamentation in mothers. Intergenerational effects of female ornamentation and prenatal stress may be interdependent drivers of balancing selection and intralocus sexual conflict over signaling traits.
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Affiliation(s)
- Braulio A. Assis
- Department of Biology, The Pennsylvania State University, University Park, PA, United States
- Intercollege Graduate Degree Program in Ecology, The Pennsylvania State University, University Park, PA, United States
- *Correspondence: Braulio A. Assis,
| | - Julian D. Avery
- Intercollege Graduate Degree Program in Ecology, The Pennsylvania State University, University Park, PA, United States
- The Department of Ecosystem Science and Management, The Pennsylvania State University, University Park, PA, United States
| | - Ryan L. Earley
- Department of Biological Sciences, University of Alabama, Tuscaloosa, AL, United States
| | - Tracy Langkilde
- Department of Biology, The Pennsylvania State University, University Park, PA, United States
- Intercollege Graduate Degree Program in Ecology, The Pennsylvania State University, University Park, PA, United States
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4
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Assis BA, Avery JD, Tylan C, Engler HI, Earley RL, Langkilde T. Honest signals and sexual conflict: Female lizards carry undesirable indicators of quality. Ecol Evol 2021; 11:7647-7659. [PMID: 34188841 PMCID: PMC8216924 DOI: 10.1002/ece3.7598] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Revised: 03/31/2021] [Accepted: 04/06/2021] [Indexed: 12/22/2022] Open
Abstract
Sex differences in animal coloration often result from sex-dependent regulatory mechanisms. Still, some species exhibit incomplete sexual dimorphism as females carry a rudimentary version of a costly male trait, leading to intralocus sexual conflict. The underlying physiology and condition dependence of these traits can inform why such conflicts remain unresolved. In eastern fence lizards (Sceloporus undulatus), blue iridophore badges are found in males and females, but melanin pigmentation underneath and surrounding badges is male-exclusive. We track color saturation and area of badges across sexual maturity, and their relationship to individual quality (body condition and immunocompetence) and relevant hormones (testosterone and corticosterone). Saturation and testosterone were positively correlated in both sexes, but hormone and trait had little overlap between males and females. Saturation was correlated with body condition and immunocompetence in males but not in females. Co-regulation by androgens may have released females from resource allocation costs of color saturation, even when in high condition. Badge area was independent of testosterone, but associated with low corticosterone in females, indicating that a nonsex hormone underlies incomplete sexual dimorphism. Given the evidence in this species for female reproductive costs associated with ornamentation, this sex-nonspecific regulation of an honest signal may underlie intralocus sexual conflict.
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Affiliation(s)
- Braulio A. Assis
- Department of BiologyThe Pennsylvania State UniversityUniversity ParkPAUSA
- Intercollege Graduate Degree Program in EcologyThe Pennsylvania State UniversityUniversity ParkPAUSA
| | - Julian D. Avery
- Intercollege Graduate Degree Program in EcologyThe Pennsylvania State UniversityUniversity ParkPAUSA
- The Department of Ecosystem Science and ManagementThe Pennsylvania State UniversityUniversity ParkPAUSA
| | - Catherine Tylan
- Department of BiologyThe Pennsylvania State UniversityUniversity ParkPAUSA
| | - Heather I. Engler
- Department of BiologyThe Pennsylvania State UniversityUniversity ParkPAUSA
| | - Ryan L. Earley
- Department of Biological SciencesUniversity of AlabamaTuscaloosaALUSA
| | - Tracy Langkilde
- Department of BiologyThe Pennsylvania State UniversityUniversity ParkPAUSA
- Intercollege Graduate Degree Program in EcologyThe Pennsylvania State UniversityUniversity ParkPAUSA
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5
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Robinson CD, Lance SL, Gifford ME. Reproductive success, apparent survival, and ventral blue coloration in male prairie lizards (
Sceloporus consobrinus
). J Zool (1987) 2021. [DOI: 10.1111/jzo.12890] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Affiliation(s)
- C. D. Robinson
- University of Virginia Charlottesville VA USA
- University of Central Arkansas Conway AR USA
| | - S. L. Lance
- Savannah River Ecology Laboratory University of Georgia Aiken SC USA
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Argaez V, Pruett JA, Seddon RJ, Solano-Zavaleta I, Hews DK, Zúñiga-Vega JJ. Steroid hormones, ectoparasites, and color: Sex, species, and seasonal differences in Sceloporus lizards. Gen Comp Endocrinol 2021; 304:113717. [PMID: 33476662 DOI: 10.1016/j.ygcen.2021.113717] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Revised: 11/06/2020] [Accepted: 01/14/2021] [Indexed: 12/20/2022]
Abstract
Testosterone, in addition to promoting the expression of sexual ornaments can negatively affect immune function, leaving individuals more susceptible to parasites (immunocompetence handicap hypothesis). Immunosuppressive effects of testosterone also can occur indirectly, through increased glucocorticoid hormones (corticosterone, cortisol). Therefore, the expression of sexual ornaments and the ability to respond to parasites and diseases may be influenced by the interaction between testosterone and corticosterone. In this study we examined correlations of both testosterone and corticosterone with ectoparasite load and with expression of colorful sexual ornaments (patches on belly and throat) in three species of Sceloporus lizards (S. grammicus, S. megalepidurus, S. torquatus). In addition, we evaluated contributions of sex, body condition, and reproductive season. We expected that individuals with higher testosterone and lower corticosterone levels would have more colorful ornaments than individuals with higher corticosterone levels. In addition, if testosterone has negative effects on immune function but only at higher corticosterone levels, individuals with higher levels of testosterone and corticosterone should have higher ectoparasite loads. Contrary to these expectations, we did not detect an interaction between testosterone and corticosterone statistically affecting either ectoparasite load or the expression of colorful ornaments. Further, we did not find a positive association of either testosterone or corticosterone on ectoparasite loads in any of the three study species. Only in S. grammicus males was a hormone statistically associated with ectoparasite load, but it was a negative association with testosterone. The relationships between both hormones and different aspects of the colorful patches (brightness and chroma) varied drastically among the three species as well as between sexes. Hence, even among congeneric species, we did not observe consistent patterns among color, steroid hormones and ectoparasites. Different associations between these variables may reflect different physiological strategies for the production of colorful signals and immune defense.
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Affiliation(s)
- Víctor Argaez
- Posgrado en Ciencias Biológicas, Universidad Nacional Autónoma de México, Ciudad Universitaria, 04510 Ciudad de México, Mexico.
| | - Jake A Pruett
- Department of Biology, Indiana State University, Terre Haute, IN 47809, USA; Department of Biological Sciences, Southeastern Oklahoma State University, Durant, OK 74701, USA.
| | - Ryan J Seddon
- Department of Biology, Indiana State University, Terre Haute, IN 47809, USA.
| | - Israel Solano-Zavaleta
- Departamento de Ecología y Recursos Naturales, Facultad de Ciencias, Universidad Nacional Autónoma de México, Ciudad Universitaria, 04510 Ciudad de México, Mexico.
| | - Diana K Hews
- Department of Biology, Indiana State University, Terre Haute, IN 47809, USA.
| | - J Jaime Zúñiga-Vega
- Departamento de Ecología y Recursos Naturales, Facultad de Ciencias, Universidad Nacional Autónoma de México, Ciudad Universitaria, 04510 Ciudad de México, Mexico.
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7
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Glover JA, Lattanzio MS. Female preferences for discrete and continuous male colour expression may help reinforce colour polymorphism in a desert lizard. BEHAVIOUR 2021. [DOI: 10.1163/1568539x-bja10068] [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
Despite recognition that colour can vary continuously, colour expression in colour polymorphic species is usually treated as discrete. We conducted three experiments to evaluate the extent that discrete and continuous male coloration influenced female mating preferences in long-tailed brush lizards (Urosaurus graciosus). Each experiment provided females with a different social context: a dimorphic choice between a yellow and an orange male (coloration treated as discrete), and a choice between either two orange males or two yellow males (coloration treated as continuous variation). Females preferred orange males over yellow males in the first experiment, and the findings of our second experiment suggested that males with moderate orange coloration were most preferred. In contrast, females behaved randomly with respect to two yellow males. Our findings show that females in colour polymorphic species can evaluate both discrete and continuous aspects of morph coloration during mate assessment, which may help maintain their polymorphism.
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Affiliation(s)
- Jenell A. Glover
- Department of Organismal and Environmental Biology, Christopher Newport University, Newport News, VA 23606, USA
| | - Matthew S. Lattanzio
- Department of Organismal and Environmental Biology, Christopher Newport University, Newport News, VA 23606, USA
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8
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Assis BA, Jarrett BJM, Koscky G, Langkilde T, Avery JD. Plastic sexual ornaments: Assessing temperature effects on color metrics in a color-changing reptile. PLoS One 2020; 15:e0233221. [PMID: 32433700 PMCID: PMC7239470 DOI: 10.1371/journal.pone.0233221] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Accepted: 04/30/2020] [Indexed: 11/19/2022] Open
Abstract
Conspicuous coloration is an important subject in social communication and animal behavior, and it can provide valuable insight into the role of visual signals in social selection. However, animal coloration can be plastic and affected by abiotic factors such as temperature, making its quantification problematic. In such cases, careful consideration is required so that metric choices are consistent across environments and least sensitive to abiotic factors. A detailed assessment of plastic trait in response to environmental conditions could help identify more robust methods for quantifying color. Temperature affects sexual ornamentation of eastern fence lizards, Sceloporus undulatus, with ventral coloration shifting from green to blue hues as temperatures rise, making the calculation of saturation (color purity) difficult under conditions where temperatures vary. We aimed to characterize how abiotic factors influence phenotypic expression and to identify a metric for quantifying animal color that is either independent from temperature (ideally) or best conserves individual's ranks. We compared the rates of change in saturation across two temperature treatments using seven metrics: three that are based on fixed spectral ranges (with two of them designed by us specifically for this system) and three that track the expressed hue (with one of them designed by us to circumvent spurious results in unornamented individuals). We also applied a lizard visual sensitivity model to understand how temperature-induced color changes may be perceived by conspecifics. We show that the rate of change in saturation between two temperatures is inconsistent across individuals, increasing at a higher rate in individuals with higher baseline saturation at lower temperatures. In addition, the relative color rank of individuals in a population varies with the temperature standardized by the investigator, but more so for some metrics than others. While we were unable to completely eliminate the effect of temperature, current tools for quantifying color allowed us to use spectral data to estimate saturation in a variety of ways and to largely preserve saturation ranks of individuals across temperatures while avoiding erroneous color scores. We describe our approaches and suggest best-practices for quantifying and interpreting color, particularly in cases where color changes in response to environmental factors.
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Affiliation(s)
- Braulio A. Assis
- Department of Biology, Intercollege Graduate Degree Program in Ecology, The Pennsylvania State University, University Park, PA, United States of America
| | - Benjamin J. M. Jarrett
- Department of Entomology, Michigan State University, East Lansing, MI, United States of America
| | - Gabe Koscky
- Independent scholar, New York, NY, United States of America
| | - Tracy Langkilde
- Department of Biology, Intercollege Graduate Degree Program in Ecology, The Pennsylvania State University, University Park, PA, United States of America
| | - Julian D. Avery
- The Department of Ecosystem Science and Management, The Pennsylvania State University, University Park, PA, United States of America
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