1
|
Batabyal A, Zambre A, Mclaren T, Rankin KJ, Somaweera R, Stuart‐Fox D, Thaker M. The extent of rapid colour change in male agamid lizards is unrelated to overall sexual dichromatism. Ecol Evol 2023; 13:e10293. [PMID: 37435020 PMCID: PMC10329938 DOI: 10.1002/ece3.10293] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2023] [Revised: 06/12/2023] [Accepted: 06/21/2023] [Indexed: 07/13/2023] Open
Abstract
Dynamic colour change is widespread in ectothermic animals, but has primarily been studied in the context of background matching. For most species, we lack quantitative data on the extent of colour change across different contexts. It is also unclear whether and how colour change varies across body regions, and how overall sexual dichromatism relates to the extent of individual colour change. In this study, we obtained reflectance measures in response to different stimuli for males and females of six species of agamid lizards (Agamidae, sister family to Chameleonidae) comprising three closely related species pairs. We computed the colour volume in a lizard-vision colour space occupied by males and females of each species and estimated overall sexual dichromatism based on the area of non-overlapping male and female colour volumes. As expected, males had larger colour volumes than females, but the extent of colour change in males differed between species and between body regions. Notably, species that were most sexually dichromatic were not necessarily those in which males showed the greatest individual colour change. Our results indicate that the extent of colour change is independent of the degree of sexual dichromatism and demonstrate that colour change on different body regions can vary substantially even between pairs of closely related species.
Collapse
Affiliation(s)
- Anuradha Batabyal
- Department of Physical and Natural SciencesFLAME UniversityPuneIndia
- Centre for Ecological SciencesIndian Institute of ScienceBengaluruIndia
| | - Amod Zambre
- Centre for Ecological SciencesIndian Institute of ScienceBengaluruIndia
- Department of Ecology, Evolution and BehaviorUniversity of MinnesotaMinneapolisMinnesotaUSA
| | - Tess Mclaren
- School of BioSciencesThe University of MelbourneParkvilleVictoriaAustralia
| | - Katrina J. Rankin
- School of BioSciencesThe University of MelbourneParkvilleVictoriaAustralia
| | - Ruchira Somaweera
- Stantec AustraliaPerthWestern AustraliaAustralia
- School of Biological SciencesUniversity of Western AustraliaPerthWestern AustraliaAustralia
| | - Devi Stuart‐Fox
- School of BioSciencesThe University of MelbourneParkvilleVictoriaAustralia
| | - Maria Thaker
- Centre for Ecological SciencesIndian Institute of ScienceBengaluruIndia
| |
Collapse
|
2
|
Amdekar MS, Thaker M. Colours of stress in male Indian rock agamas predict testosterone levels but not performance. Horm Behav 2022; 144:105214. [PMID: 35696781 DOI: 10.1016/j.yhbeh.2022.105214] [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: 10/31/2021] [Revised: 05/26/2022] [Accepted: 05/31/2022] [Indexed: 11/28/2022]
Abstract
Rapid physiological colour change offers dynamic signalling opportunities that can reveal distinct information to receivers in different contexts. Information content in dynamic colours, however, is largely unexplored. In males of the Indian rock agama (Psammophilus dorsalis), stressful events, including male-male agonistic interactions, induce a colour change, wherein the dorsal band turns yellow and the lateral bands turn orange. We aimed to determine whether these pigment-based dynamic colours convey information about individual quality. Using an agamid-specific visual model, we first quantified the chromatic and achromatic contrasts of each colour component displayed by males during handling stress, which induces the maximal response of aggression-typical colours. We then measured baseline testosterone levels, morphology (body mass and size), and performance measures (bite force and sprint speed) of these lizards. Chromatic contrasts of the dorsal yellow and lateral orange bands, individually and relative to each other (internal pair), were negatively correlated with testosterone levels, while the chromatic contrast of the internal pair was positively correlated with body condition. The lack of an association between colour contrasts and both bite force and sprint speed indicate that the conspicuousness of colours expressed during stressful events, such as agonistic interactions, do not reveal male performance ability. Despite our expectations of a positive relationship with testosterone, morphology (body condition), and performance (bite force, sprint speed), we find that for P. dorsalis, the conspicuousness of stress-induced colours provide only some information about individual quality. We speculate that the dynamicity of physiological colours may influence their function as content-containing signals in social interactions.
Collapse
Affiliation(s)
- Madhura S Amdekar
- Centre for Ecological Sciences, Indian Institute of Science, Bengaluru 560012, India
| | - Maria Thaker
- Centre for Ecological Sciences, Indian Institute of Science, Bengaluru 560012, India.
| |
Collapse
|
3
|
Do male panther chameleons use different aspects of color change to settle disputes? Naturwissenschaften 2022; 109:13. [DOI: 10.1007/s00114-022-01784-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Revised: 12/23/2021] [Accepted: 01/06/2022] [Indexed: 10/19/2022]
|
4
|
|
5
|
Mohanty NP, Joshi M, Thaker M. Urban lizards use sleep sites that mirror the structural, thermal, and light properties of natural sites. Behav Ecol Sociobiol 2021. [DOI: 10.1007/s00265-021-03101-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
|
6
|
Balakrishna S, Amdekar MS, Thaker M. Morphological divergence, tail loss, and predation risk in urban lizards. Urban Ecosyst 2021. [DOI: 10.1007/s11252-021-01122-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
7
|
Heinen‐Kay JL, Kay AD, Zuk M. How urbanization affects sexual communication. Ecol Evol 2021; 11:17625-17650. [PMID: 35003629 PMCID: PMC8717295 DOI: 10.1002/ece3.8328] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Revised: 09/30/2021] [Accepted: 10/05/2021] [Indexed: 11/17/2022] Open
Abstract
Urbanization is rapidly altering landscapes worldwide, changing environmental conditions, and creating novel selection pressures for many organisms. Local environmental conditions affect the expression and evolution of sexual signals and mating behaviors; changes in such traits have important evolutionary consequences because of their effect on reproduction. In this review, we synthesize research investigating how sexual communication is affected by the environmental changes associated with urbanization-including pollution from noise, light, and heavy metals, habitat fragmentation, impervious surfaces, urban heat islands, and changes in resources and predation. Urbanization often has negative effects on sexual communication through signal masking, altering condition-dependent signal expression, and weakening female preferences. Though there are documented instances of seemingly adaptive shifts in trait expression, the ultimate impact on fitness is rarely tested. The field of urban evolution is still relatively young, and most work has tested whether differences occur in response to various aspects of urbanization. There is limited information available about whether these responses represent phenotypic plasticity or genetic changes, and the extent to which observed shifts in sexual communication affect reproductive fitness. Our understanding of how sexual selection operates in novel, urbanized environments would be bolstered by more studies that perform common garden studies and reciprocal transplants, and that simultaneously evaluate multiple environmental factors to tease out causal drivers of observed phenotypic shifts. Urbanization provides a unique testing ground for evolutionary biologists to study the interplay between ecology and sexual selection, and we suggest that more researchers take advantage of these natural experiments. Furthermore, understanding how sexual communication and mating systems differ between cities and rural areas can offer insights on how to mitigate negative, and accentuate positive, consequences of urban expansion on the biota, and provide new opportunities to underscore the relevance of evolutionary biology in the Anthropocene.
Collapse
Affiliation(s)
- Justa L. Heinen‐Kay
- Department of Ecology, Evolution & BehaviorUniversity of MinnesotaSt. PaulUSA
| | - Adam D. Kay
- Biology DepartmentUniversity of St. ThomasSt. PaulUSA
| | - Marlene Zuk
- Department of Ecology, Evolution & BehaviorUniversity of MinnesotaSt. PaulUSA
| |
Collapse
|
8
|
Dickerson AL, Rankin KJ, Cadena V, Endler JA, Stuart-Fox D. Rapid beard darkening predicts contest outcome, not copulation success, in bearded dragon lizards. Anim Behav 2020. [DOI: 10.1016/j.anbehav.2020.10.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
|
9
|
Dollion AY, Herrel A, Marquis O, Leroux-Coyau M, Meylan S. The colour of success: does female mate choice rely on male colour change in the chameleon Furcifer pardalis? J Exp Biol 2020; 223:jeb224550. [PMID: 32843362 DOI: 10.1242/jeb.224550] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Accepted: 08/20/2020] [Indexed: 01/14/2023]
Abstract
Colour change is involved in various functions ranging from thermo- and hydroregulation to camouflage and communication. The role of colour change in communication has received increased attention over the past few decades, yet has been studied predominantly in the context of intrasexual competition. Here, we investigate the role of colour change in mate choice in an animal that can change its colour, the panther chameleon (Furcifer pardalis). We conducted behavioural experiments and colour analysis to investigate whether colour changes, including in the UV range, are involved in mate choice. This study presents evidence of female mate choice for specific aspects of colour change in courting males, both in the visible (i.e. human visible range: 400-700 nm) and the UV range. Females chose males exhibiting more saturation changes regardless of the body region and spectral range. In addition, females chose males showing fewer brightness changes at the level of the lateral line and males showing lower hue changes at the level of the bands and the interbands, in the visible range. At UV wavelengths, selected males showed more brightness changes and higher maximum brightness. These results suggest that male colour change is important in female mate choice in the panther chameleon.
Collapse
Affiliation(s)
- Alexis Y Dollion
- Université de Paris, 75006 Paris, France
- Sorbonne Université, CNRS, IRD, INRA, Institut d'Ecologie et des Sciences de l'Environnement-Paris, iEES-Paris, 75252 Paris, France
- Département Adaptations du vivant, UMR 7179 C.N.R.S/M.N.H.N, 75005 Paris, France
| | - Anthony Herrel
- Département Adaptations du vivant, UMR 7179 C.N.R.S/M.N.H.N, 75005 Paris, France
| | - Olivier Marquis
- Muséum national d'Histoire naturelle, Parc Zoologique de Paris, 75012 Paris, France
| | - Mathieu Leroux-Coyau
- Sorbonne Université, CNRS, IRD, INRA, Institut d'Ecologie et des Sciences de l'Environnement-Paris, iEES-Paris, 75252 Paris, France
| | - Sandrine Meylan
- Sorbonne Université, CNRS, IRD, INRA, Institut d'Ecologie et des Sciences de l'Environnement-Paris, iEES-Paris, 75252 Paris, France
| |
Collapse
|
10
|
Amdekar MS, Thaker M. Risk of social colours in an agamid lizard: implications for the evolution of dynamic signals. Biol Lett 2019; 15:20190207. [PMID: 31088284 DOI: 10.1098/rsbl.2019.0207] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The forces of sexual and natural selection are typically invoked to explain variation in colour patterns of animals. Although the benefits of conspicuous colours for social signalling are well documented, evidence for their ecological cost, especially for dynamic colours, remains limited. We examined the riskiness of colour patterns of Psammophilus dorsalis, a species in which males express distinct colour combinations during social interactions. We first measured the conspicuousness of these colour patterns on different substrates based on the visual systems of conspecifics and predators (bird, snake, canid) and then quantified actual predation risk on these patterns using wax/polymer lizard models in the wild. The black and red male state exhibited during courtship was the most conspicuous to all visual systems, while the yellow and orange male aggression state and the brown female colour were least conspicuous. Models bearing the courtship colour pattern experienced the highest predator attacks, irrespective of the substrate they were placed on. Thus, social colours of males are not only conspicuous but also risky. Using physiological colours to shift in and out of conspicuous states may be an effective evolutionary solution to balance social signalling benefits with predation costs.
Collapse
Affiliation(s)
- Madhura S Amdekar
- Centre for Ecological Sciences, Indian Institute of Science , Bengaluru 560012 , India
| | - Maria Thaker
- Centre for Ecological Sciences, Indian Institute of Science , Bengaluru 560012 , India
| |
Collapse
|
11
|
Batabyal A, Thaker M. Social coping styles of lizards are reactive and not proactive in urban areas. Gen Comp Endocrinol 2019; 270:67-74. [PMID: 30336119 DOI: 10.1016/j.ygcen.2018.10.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/18/2018] [Revised: 10/04/2018] [Accepted: 10/14/2018] [Indexed: 01/05/2023]
Abstract
Animals engage in social interactions with changes in their behaviour and physiology. Environmental challenges, however, can influence social interactions by adding additional stressors. Here, we investigated the effects of urbanisation on the behaviour and hormonal responses of a tropical lizard species, Psammophilus dorsalis, during social interactions. We recorded behaviour of males from suburban and rural areas during controlled encounters with other males and females. We then measured corticosterone and testosterone levels of individuals at 10 min intervals, from immediately after the social encounter to 30 min later and then at 120 min after the interaction period. We found that differences in social behaviours and subsequent hormone levels were largely driven by habitat, and not social context. Overall, we found that fewer suburban males showed behavioural displays compared to rural males during social encounters. For those that displayed, intensity of aggression was similar across populations, but courtship intensity was lower for suburban males compared to rural males. Suburban males also had significantly elevated levels of corticosterone both under control conditions (no social encounter) and following intra- and intersexual interactions, while rural males retained low levels of corticosterone across contexts. Social interactions were associated with an increase in testosterone levels in all males, but only rural males maintained elevated levels for up to 120 min after interactions with females. Thus, lizards from these suburban and rural populations showed key differences in responsiveness to and recovery from social challenges, a pattern that suggests alternative coping styles ('proactive' vs. 'reactive'). These differences in social coping styles could influence consequences of sexual selection in an urbanised world.
Collapse
Affiliation(s)
- Anuradha Batabyal
- Centre for Ecological Sciences, Indian Institute of Science, Bangalore 560012, India.
| | - Maria Thaker
- Centre for Ecological Sciences, Indian Institute of Science, Bangalore 560012, India
| |
Collapse
|
12
|
Amdekar MS, Kakkar A, Thaker M. Measures of Health Provide Insights Into the Coping Strategies of Urban Lizards. Front Ecol Evol 2018. [DOI: 10.3389/fevo.2018.00128] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
|
13
|
Ligon RA, McGraw KJ. A chorus of color: hierarchical and graded information content of rapid color change signals in chameleons. Behav Ecol 2018. [DOI: 10.1093/beheco/ary076] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Russell A Ligon
- School of Life Sciences, Arizona State University, Tempe, AZ, USA
| | - Kevin J McGraw
- School of Life Sciences, Arizona State University, Tempe, AZ, USA
| |
Collapse
|
14
|
Deodhar S, Isvaran K. Why Do Males Use Multiple Signals? Insights From Measuring Wild Male Behavior Over Lifespans. Front Ecol Evol 2018. [DOI: 10.3389/fevo.2018.00075] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
|
15
|
Batabyal A, Thaker M. Lizards assess complex social signals by lateralizing colour but not motion detection. J Exp Biol 2018; 221:jeb.173252. [DOI: 10.1242/jeb.173252] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2017] [Accepted: 01/11/2018] [Indexed: 01/12/2023]
Abstract
Vertebrates lateralize many behaviours including social interactions. Social displays typically comprise multiple components, yet our understanding of how these are processed come from studies that typically examine responses to the dominant component or the complex signal as a whole. Here, we examine laterality in lizard responses to determine whether receivers separate the processing of motion and colour signal components in different brain hemispheres. In Psammophilus dorsalis, males display colours that dynamically change during courtship and aggressive interactions. We tested the visual grasp reflex of both sexes using robotic stimuli that mimicked two signal components: (1) multiple speeds of head-bobbing behaviour and (2) multiple colours. We find no laterality in response to different motion stimuli, indicating that motion similarly attracts attention from both visual fields across sexes. Notably, receivers showed left visual field dominance to colours, especially when males were exposed to “aggression-specific” colours and females to “courtship-specific” colours.
Collapse
Affiliation(s)
- Anuradha Batabyal
- Centre for Ecological Sciences, Indian Institute of Science, Bangalore 560012, India
| | - Maria Thaker
- Centre for Ecological Sciences, Indian Institute of Science, Bangalore 560012, India
| |
Collapse
|
16
|
Clark DL, Macedonia JM, Rowe JW, Kamp K, Valle CA. Responses of Galápagos Lava Lizards (Microlophus bivittatus) to Manipulation of Female Nuptial Coloration on Lizard Robots. HERPETOLOGICA 2017. [DOI: 10.1655/herpetologica-d-16-00056] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- David L. Clark
- Department of Biology, Alma College, Alma, MI 48801, USA
| | | | - John W. Rowe
- Department of Biology, Alma College, Alma, MI 48801, USA
| | - Kendall Kamp
- Department of Biology, Alma College, Alma, MI 48801, USA
| | - Carlos A. Valle
- Colegio de Ciencias Biológicas y Ambientales, Universidad San Francisco de Quito, Campus Cumbayá Av. Diego de Robles S/N e Interoceánica, Quito, Ecuador
| |
Collapse
|