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de La Cruz F, Pérez i de Lanuza G, Font E. Signalling on islands: the case of Lilford’s wall lizard ( Podarcis lilfordi gigliolii) from Dragonera. Biol J Linn Soc Lond 2023. [DOI: 10.1093/biolinnean/blac152] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/19/2023]
Abstract
AbstractStudies of the effects of insularity on animal signals are scarce, particularly in lizards. Here, we use Lilford’s wall lizard from Dragonera (Podarcis lilfordi gigliolii) to ask how island conditions have affected its repertoire of social signals, focusing on two visual signals shared by many Podarcis species: ultraviolet (UV)–blue-reflecting ventrolateral colour patches and visual displays. We examined whether the number or spectral characteristics of the UV–blue patches are associated with traits related to individual quality. We also used visual models to assess visual conspicuousness and to measure sexual dichromatism. We did not observe foot shakes or any other visual displays usually found in continental Podarcis. We found that none of the UV–blue patch variables covaried with morphometric variables indicative of fighting ability or body condition in males, suggesting that this coloration does not signal individual quality. We also found very little sexual dichromatism. In particular, the UV–blue patches of females seem over-expressed and more similar to those of males than those of continental Podarcis. Ancestral state reconstruction reveals that the lack of sexual dimorphism in the UV–blue patches is a derived condition for P. lilfordi gigliolii and other Podarcis living on small islands. Our results thus show a pattern of reduced social signalling in P. lilfordi gigliolii relative to mainland Podarcis, with some signals being lost or under-expressed (visual displays) and others losing their signalling function (UV–blue patches). We hypothesize that these changes are attributable to the high population density of P. lilfordi gigliolii, which discourages territorial behaviour and promotes extreme social tolerance, making most social signals unnecessary. More work will be needed to determine whether this is a common pattern in lizards inhabiting small and densely populated islands.
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Affiliation(s)
- Ferran de La Cruz
- Ethology Lab, Cavanilles Institute of Biodiversity and Evolutionary Biology, University of Valencia , APDO 22085, 46071 , Spain
- CIBIO Research Centre in Biodiversity and Genetic Resources, InBIO, Campus de Vairão, Universidade do Porto , 4485-661 , Portugal
| | - Guillem Pérez i de Lanuza
- Ethology Lab, Cavanilles Institute of Biodiversity and Evolutionary Biology, University of Valencia , APDO 22085, 46071 , Spain
| | - Enrique Font
- Ethology Lab, Cavanilles Institute of Biodiversity and Evolutionary Biology, University of Valencia , APDO 22085, 46071 , Spain
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Zúñiga-Vega JJ, Pruett JA, Ossip-Drahos AG, Campos SM, Seddon RJ, Price SL, Romero-Diaz C, Rivera JA, Vital-García C, Hews DK, Martins EP. Information out of the blue: phenotypic correlates of abdominal color patches in Sceloporus lizards. ZOOLOGY 2021; 149:125961. [PMID: 34592493 DOI: 10.1016/j.zool.2021.125961] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Revised: 08/12/2021] [Accepted: 08/19/2021] [Indexed: 11/28/2022]
Abstract
Colorful ornaments are important visual signals for animal communication that can provide critical information about the quality of the signaler. In this study, we focused on different color characteristics of the abdominal patches of males of six lizard species from the genus Sceloporus. We addressed three main objectives. First, we examined if size, brightness, saturation, and conspicuousness of these ornaments are indicative of body size, condition, immune function, or levels of testosterone and corticosterone. Second, we evaluated if the distinct components of these abdominal patches (blue or green patches and black stripes) transmit similar information about the signaler, which would support the redundant signal hypothesis, or if these components are related to different phenotypic traits, which would support the multiple message hypothesis. Third, we compared the phenotypic correlates of these ornaments among our six species to understand the degree of conservatism in the signaling patterns or to find species-specific signals. Using data collected from males in natural conditions and a multi-model inference framework, we found that in most species the area of the patches and the brightness of the blue component are positively related to body size. Thus, these color characteristics are presumably indicative of the physical strength and competitive ability of males and these shared signals were likely inherited from a common ancestor. In half of the species, males in good body condition also exhibit relatively larger blue and black areas, suggesting that the expression of these ornaments is condition-dependent. Abdominal patches also provide information about immunocompetence of the males as indicated by different correlations between certain color characteristics and ectoparasite load, counts of heterophils, and the heterophil:lymphocyte ratio. Our findings reveal that area and brightness of the abdominal patches signal the size and body condition of males, whereas blue saturation and conspicuousness with respect to the surrounding substrate are indicative of immune condition, thus supporting the multiple message hypothesis. However, some of these correlations were not shared by all species and, hence, point to intriguing species-specific signals.
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Affiliation(s)
- J Jaime Zúñiga-Vega
- Departamento de Ecología y Recursos Naturales, Facultad de Ciencias, Universidad Nacional Autónoma de México, Circuito Exterior s/n, Ciudad Universitaria, Coyoacán, Mexico City, 04510, Mexico.
| | - Jake A Pruett
- Department of Biology, Indiana State University, Science Building Room 283, 600 North Chestnut Street, Terre Haute, IN 47809, USA; Department of Biological Sciences, Southeastern Oklahoma State University, 425 W. University Boulevard, Durant, OK 74701, USA.
| | - Alison G Ossip-Drahos
- Department of Chemistry and Physical Sciences, Marian University, 3200 Cold Springs Road, Indianapolis, IN 46222, USA.
| | - Stephanie M Campos
- Biology Department, Swarthmore College, 500 College Avenue, Swarthmore, PA 19081, USA.
| | - Ryan J Seddon
- Department of Biology, Indiana State University, Science Building Room 283, 600 North Chestnut Street, Terre Haute, IN 47809, USA; Center for Global Communication Strategies, University of Tokyo, 3-8-4 Komaba, Meguro-ku, Tokyo, 153-8902, Japan.
| | - Savannah L Price
- Department of Biology, Indiana State University, Science Building Room 283, 600 North Chestnut Street, Terre Haute, IN 47809, USA.
| | - Cristina Romero-Diaz
- School of Life Sciences, Arizona State University, 427 East Tyler Mall, Tempe, AZ 85287, USA.
| | - Julio A Rivera
- School of Life Sciences, Arizona State University, 427 East Tyler Mall, Tempe, AZ 85287, USA.
| | - Cuauhcihuatl Vital-García
- Departamento de Ciencias Veterinarias, Universidad Autónoma de Ciudad Juárez, Anillo Envolvente y Estocolmo s/n, Colonia Progresista, Ciudad Juárez, Chihuahua, 32310, Mexico.
| | - Diana K Hews
- Department of Biology, Indiana State University, Science Building Room 283, 600 North Chestnut Street, Terre Haute, IN 47809, USA.
| | - Emília P Martins
- School of Life Sciences, Arizona State University, 427 East Tyler Mall, Tempe, AZ 85287, USA.
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