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Barquero MD. Population variation in signaling behavior and contest outcome in the jacky dragon. Aggress Behav 2024; 50:e22166. [PMID: 39030757 DOI: 10.1002/ab.22166] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2024] [Revised: 07/07/2024] [Accepted: 07/08/2024] [Indexed: 07/22/2024]
Abstract
Being aggressive and by extension, dominant, is an important mechanism for determining access to resources such as mates or territories. While predictors of contest outcome and dominance are increasingly studied, we have a poor understanding of how they vary across populations. Here, I use the widely distributed Australian agamid lizard, the Jacky dragon (Amphibolurus muricatus), to quantify variation in features predicting contest outcome among males of different populations. I measured physical attributes, maximal physiological performance capacity (sprint speed, endurance, bite force) and visual displays during staged encounters. I found that morphology, performance capacity and the type and frequency of visual displays used during agonistic interactions varied significantly across populations. Contest winners from the Cann River State Forest population favored tail-flicks and push-up/body-rocks, while those from Royal National Park were more likely to chase and individuals from Yarratt State Forest performed more bite-lunges than other populations. The losers of contests also differed in their displays. Individuals from the Cann River population were dominant over the others based on behavioral attributes (i.e., aggressive visual displays, chases and bite-lunges). I suggest that population differences in signal form and function could have implications for range dynamics as populations come into contact in an era of rapid environmental change.
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Affiliation(s)
- Marco D Barquero
- Department of Biological Sciences, Macquarie University, Sydney, New South Wales, Australia
- Sede del Caribe, Universidad de Costa Rica, Montes de Oca, San José, Costa Rica
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2
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Mancero EJ, Valle CA, Rowe JW, Moore JA, Clark DL. Sexual Selection in San Cristóbal Lava Lizards (Microlophus bivittatus): A Test of Male Body Size Using Lizard Robots. HERPETOLOGICA 2022. [DOI: 10.1655/herpetologica-d-20-00058] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Emilio J. Mancero
- Universidad San Francisco de Quito USFQ, Colegio de Ciencias Biológicas y Ambientales COCIBA, Campus Cumbayá, Avenida Diego de Robles S/N e Interoceánica, Quito, Ecuador
| | - Carlos A. Valle
- Universidad San Francisco de Quito USFQ, Colegio de Ciencias Biológicas y Ambientales COCIBA, Campus Cumbayá, Avenida Diego de Robles S/N e Interoceánica, Quito, Ecuador
| | - John W. Rowe
- Department of Biology, Alma College, Alma, MI 48801, USA
| | - Jennifer A. Moore
- Biology Department, Grand Valley State University, Allendale, MI 49401, USA
| | - David L. Clark
- Department of Biology, Alma College, Alma, MI 48801, USA
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3
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Nagloo N, Coimbra JP, Hoops D, Hart NS, Collin SP, Hemmi JM. Retinal topography and microhabitat diversity in a group of dragon lizards. J Comp Neurol 2020; 528:542-558. [PMID: 31576574 DOI: 10.1002/cne.24780] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Revised: 08/28/2019] [Accepted: 09/13/2019] [Indexed: 12/25/2022]
Abstract
The well-studied phylogeny and ecology of dragon lizards and their range of visually mediated behaviors provide an opportunity to examine the factors that shape retinal organization. Dragon lizards consist of three evolutionarily stable groups based on their shelter type, including burrows, shrubs, and rocks. This allows us to test whether microhabitat changes are reflected in their retinal organization. We examined the retinae of three burrowing species (Ctenophorus pictus, C. gibba, and C. nuchalis), and three species that shelter in rock crevices (C. ornatus, C. decresii, and C. vadnappa). We used design-based stereology to sample both the photoreceptor array and neurons within the retinal ganglion cell layer to estimate areas specialized for acute vision. All species had two retinal specializations mediating enhanced spatial acuity: a fovea in the retinal center and a visual streak across the retinal equator. Furthermore, all species featured a dorsoventrally asymmetric photoreceptor distribution with higher photoreceptor densities in the ventral retina. This dorsoventral asymmetry may provide greater spatial summation of visual information in the dorsal visual field. Burrow-dwelling species had significantly larger eyes, higher total numbers of retinal cells, higher photoreceptor densities in the ventral retina, and higher spatial resolving power than rock-dwelling species. C. pictus, a secondary burrow-dwelling species, was the only species that changed burrow usage over evolutionary time, and its retinal organization revealed features more similar to rock-dwelling species than other burrow-dwelling species. This suggests that phylogeny may play a substantial role in shaping retinal organization in Ctenophorus species compared to microhabitat occupation.
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Affiliation(s)
- Nicolas Nagloo
- School of Biological Sciences, The University of Western Australia, Crawley, Western Australia, Australia.,The Oceans Institute and Oceans Graduate School, The University of Western Australia, Crawley, Western Australia, Australia.,Department of Evolutionary Studies of Biosystems, SOKENDAI (The Graduate University for Advanced Studies), Hayama, Japan
| | - João Paulo Coimbra
- School of Anatomical Sciences, The University of the Witwatersrand, Johannesburg, South Africa
| | - Daniel Hoops
- Ecology and Evolution, Research School of Biology, The Australian National University, Canberra, Australian Capital Territory, Australia
| | - Nathan S Hart
- School of Biological Sciences, The University of Western Australia, Crawley, Western Australia, Australia.,The Oceans Institute and Oceans Graduate School, The University of Western Australia, Crawley, Western Australia, Australia.,Department of Biological Sciences, Macquarie University, Sydney, New South Wales, Australia
| | - Shaun P Collin
- School of Biological Sciences, The University of Western Australia, Crawley, Western Australia, Australia.,The Oceans Institute and Oceans Graduate School, The University of Western Australia, Crawley, Western Australia, Australia.,School of Life Science, La Trobe University, Bundoora, Victoria, Australia
| | - Jan M Hemmi
- School of Biological Sciences, The University of Western Australia, Crawley, Western Australia, Australia.,The Oceans Institute and Oceans Graduate School, The University of Western Australia, Crawley, Western Australia, Australia
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Inden B, Jost J. Evolving neural networks to follow trajectories of arbitrary complexity. Neural Netw 2019; 116:224-236. [DOI: 10.1016/j.neunet.2019.04.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Revised: 12/28/2018] [Accepted: 04/10/2019] [Indexed: 10/26/2022]
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Ramos JA, Peters RA. Dragon wars: Movement-based signalling by Australian agamid lizards in relation to species ecology. AUSTRAL ECOL 2015. [DOI: 10.1111/aec.12312] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- José Antonio Ramos
- Animal Behaviour Group; Department of Ecology, Environment and Evolution; La Trobe University; Bundoora Victoria 3083 Australia
| | - Richard Anthony Peters
- Animal Behaviour Group; Department of Ecology, Environment and Evolution; La Trobe University; Bundoora Victoria 3083 Australia
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Halstead JE, Schwanz LE. Impacts of thermal limitation on thermoregulatory behaviour and reproductive success in a lizard. AUST J ZOOL 2015. [DOI: 10.1071/zo15012] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Climatic variation can impact populations of ectotherms by altering reproduction, development, and survival. While a warm climate can provide additional thermal opportunities for ectotherms, excessively warm conditions can restrict activity in avoidance of lethal temperatures. However, ectotherms are not necessarily passive to thermal conditions, and often employ flexible thermoregulatory behaviour to accommodate environmental variation. Here, we examine whether the Australian jacky dragon lizard, Amphibolurus muricatus, can compensate for reduced basking opportunity by basking with greater intensity, and how the thermal environment influences reproductive success in females. Overall, there was no compelling evidence for compensatory thermoregulatory behaviour in response to reduced basking opportunity. Moreover, females with reduced thermal opportunities did not produce eggs, although reproductive success was quite low for both groups, so additional factors may have limited reproduction in the colony. This study allows insight into the links between climate and population persistence in wild animals by providing crucial and rare data on how thermal environment impacts reproduction in an egg-laying lizard.
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Baird TA, Lovern MB, Shine R. Heightened aggression and winning contests increase corticosterone but decrease testosterone in male Australian water dragons. Horm Behav 2014; 66:393-400. [PMID: 24907453 DOI: 10.1016/j.yhbeh.2014.05.008] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/15/2013] [Revised: 05/25/2014] [Accepted: 05/27/2014] [Indexed: 11/19/2022]
Abstract
Water dragons (Intellegama [Physignathus] lesueurii) are large (to >1m) agamid lizards from eastern Australia. Males are fiercely combative; holding a territory requires incessant displays and aggression against other males. If a dominant male is absent, injured or fatigued, another male soon takes over his territory. Our sampling of blood from free-ranging adult males showed that baseline levels of both testosterone and corticosterone were not related to a male's social tactic (territorial versus non-territorial), or his frequency of advertisement display, aggression, or courtship behavior. Even when we elicited intense aggression by non-territorial males (by temporarily removing territory owners), testosterone did not increase with the higher levels of aggression that ensued. Indeed, testosterone levels decreased in males that won contests. In contrast, male corticosterone levels increased with the heightened aggression during unsettled conditions, and were higher in males that won contests. High chronic male-male competition in this dense population may favor high testosterone levels in all adult males to facilitate advertisement and patrol activities required for territory maintenance (by dominant animals), and to maintain readiness for territory take-overs (in non-territorial animals). Corticosterone levels increased in response to intense aggression during socially unstable conditions, and were higher in contest winners than losers. A positive correlation between the two hormones during socially unstable conditions suggests that the high stress of contests decreased androgen production. The persistent intense competition in this population appears to exact a high physiological cost, which together with our observation that males sometimes lose their territories to challengers may indicate cycling between these two tactics to manage long-term energetic costs.
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Affiliation(s)
- Troy A Baird
- Department of Biology, University of Central Oklahoma, USA.
| | - Matthew B Lovern
- Department of Zoology, Oklahoma State University, Stillwater, OK, USA 74078.
| | - Richard Shine
- School of Biological Sciences, University of Sydney, NSW, Australia.
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Baird TA, Baird TD, Shine R. Aggressive transition between alternative male social tactics in a long-lived Australian dragon (Physignathus lesueurii) living at high density. PLoS One 2012; 7:e41819. [PMID: 22905109 PMCID: PMC3414507 DOI: 10.1371/journal.pone.0041819] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2012] [Accepted: 06/26/2012] [Indexed: 11/18/2022] Open
Abstract
Theory predicts the evolution of alternative male social tactics when intense competition coupled with the superior competitive ability of some individuals limits access to reproductive opportunities by others. How selection has shaped alternative social tactics may be especially interesting in long-lived species where size among sexually mature males varies markedly. We conducted experimental studies on long-lived eastern Australian water dragons living where competition was intense to test the hypotheses that mature males adopt alternative social tactics that are plastic, and that large size and body condition determine resource-holding potential. Approximately one-half of mature males (N = 14) defended territories using high rates of patrol and advertisement display, whereas 16 smaller mature males having lower body condition indices utilized non-territorial social tactics. Although territorial males were larger in absolute size and head dimensions, their heads were not allometrically larger. Territorial males advertised very frequently using displays involving stereotypical movements of the head and dewlap. More aggressive displays were given infrequently during baseline social conditions, but increased during periods of social instability. Female home ranges overlapped those of several territorial and non-territorial males, but females interacted more frequently with territorial males. The extreme plasticity of social tactics in this species that are dependent on body size was confirmed by two instances when relatively large non-territorial males spontaneously evicted territory owners, and by marked shifts in tactics by non-territorial males in response to temporary experimental removals of territory owners, followed (usually) by their expulsion when original owners were reinstated. The high level of social plasticity in this population where same-sex competitors are densely concentrated in preferred habitat suggests that chronic high energetic costs of defense may select for males to cycle between territorial and non-territorial social tactics depending upon their changing energetic status and their current capacity for competition with rivals.
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Affiliation(s)
- Troy A Baird
- Department of Biology, University of Central Oklahoma, Edmond, Oklahoma, United States of America.
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STUART-SMITH JEMINAF, STUART-SMITH RICKD, SWAIN ROY, WAPSTRA ERIK. Size dimorphism in Rankinia [Tympanocryptis] diemensis (Family Agamidae): sex-specific patterns and geographic variation. Biol J Linn Soc Lond 2008. [DOI: 10.1111/j.1095-8312.2008.01026.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Stuart-Smith J, Swain R, Stuart-Smith RD, Wapstra E. Is fecundity the ultimate cause of female-biased size dimorphism in a dragon lizard? J Zool (1987) 2007. [DOI: 10.1111/j.1469-7998.2007.00324.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Cuervo JJ, Shine R. Hues of a dragon's belly: morphological correlates of ventral coloration in water dragons. J Zool (1987) 2007. [DOI: 10.1111/j.1469-7998.2007.00328.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Radder RS, Saidapur SK, Shine R, Shanbhag BA. The language of lizards: interpreting the function of visual displays of the Indian rock lizard, Psammophilus dorsalis (Agamidae). J ETHOL 2006. [DOI: 10.1007/s10164-006-0192-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Watt MJ, Forster GL, Joss JMP. Steroid correlates of territorial behavior in male jacky dragons, Amphibolurus muricatus. BRAIN, BEHAVIOR AND EVOLUTION 2003; 61:184-94. [PMID: 12784056 DOI: 10.1159/000070702] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2002] [Accepted: 02/04/2003] [Indexed: 11/19/2022]
Abstract
Male jacky dragons, Amphibolurus muricatus, indicate territoriality to rivals during the mating season through the use of stereotyped motor displays. The relationship between corticosterone (B) and testosterone (T) and its effects on territorial display expression were investigated in captive lizards. Results demonstrated that territorial display production was most effectively predicted by elevated baseline T levels. This parallels the heightened T concentrations exhibited by males in the field during the spring mating period. The effect of social interaction on B and T levels was also examined by presenting territory-holding males with a size-matched male intruder. Resident males exhibited clear differences in the level of territorial response evoked by a male intruder, which were correlated with differences in physiological activity. Males that gave no territorial response had moderate B levels that did not change with social interaction, and significantly lower T levels than males that responded to the intruder with territorial displays. Among displaying males, those exhibiting low levels of territorial responses showed no change in B or T. In contrast, high-level territorial responders exhibited acute B increases when faced with an intruder, which might assist in supporting sustained metabolic activity and could possibly reflect differences in the perception of social stress. These same males also exhibited a reduction in T levels at such times, probably due to the acute rise in B. Combined, these results suggest that high circulating T is acting in a preparatory manner to increase the likelihood of producing a territorial response upon engaging in a social encounter. However, once this response has been initiated T may not need to remain elevated to allow continued expression of territorial behavior.
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Affiliation(s)
- Michael J Watt
- Department of Biological Sciences, Macquarie University, Sydney, Australia.
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