Population dependent behavioral responses among color morphs of European wall lizard (Podarcis muralis)?

From Firenze University Press Journal: Acta Herpetologica

Lekshmi B. Sreelatha, CIBIO-InBIO, Universidade do Porto

Guillem Pérez i de Lanuza, CIBIO-InBIO Associate Laboratory, Research Centre in Biodiversity and Genetic Resources, University of Porto

Oleksandra Oskyrko, CIBIO-InBIO Associate Laboratory, Research Centre in Biodiversity and Genetic Resources, University of Porto

Verónica Gomes, CIBIO-InBIO Associate Laboratory, Research Centre in Biodiversity and Genetic Resources, University of Porto

Pedro Andrade, CIBIO-InBIO Associate Laboratory, Research Centre in Biodiversity and Genetic Resources, University of Porto

Zbyszek Boratyński, CIBIO-InBIO Associate Laboratory, Research Centre in Biodiversity and Genetic Resources, University of Porto

Miguel A. Carretero, CIBIO-InBIO Associate Laboratory, Research Centre in Biodiversity and Genetic Resources, University of Porto

Coexistence of multiple categorical color phenotypes within a single population (color polymorphism) has been reported throughout the animal kingdom, including lizards (Sinervo and Lively, 1996; Svensson, 2017). Main-tenance of alternative genetically determined color phe-notypes (i.e., color morphs) is often explained by com-plex evolutionary processes involving multiple selective forces (Sinervo and Lively, 1996; Svensson, 2017). Such morphs should be either characterized by equal fitness, or if fitness differences exist, rare morphs should be promot-ed by selection (Sinervo and Lively, 1996). This is usually explained as a consequence of the co-variation between color and other phenotypic traits, which results in devel-opment of alternative strategies involving complex com-binations of behavioral, physiological, morphological or life history characteristics (Coladonato et al., 2020; Gale-otti et al., 2013; Sacchi et al., 2007; Sinervo and Lively, 1996; Svensson et al., 2001; Thompson et al., 2023). In reptiles, variation in color within populations (including those that may be polymorphic) is often interpreted as an adaptive compromise between conflicting selective pres-sures exerted by social, antipredator, and thermoregula-tory functions (Cooper and Greenberg, 1992).Functional traits that sometimes covary with color, such as locomotor behavior, can influence the fitness of alternative color morphs and play a major role in regu-lating selective processes (Grant and Liebgold, 2017; Sreelatha et al., 2021). Animals with more active loco-motion may be more exposed to predators and, hence, suffer increased risk of mortality (Werner and Anholt, 2015). However, high locomotor activity can be advanta-geous for finding resources (foraging or basking spots) as well as for social, and reproductive interactions (Arnold and Bennett, 1988; Boratyński, 2020; Huyghe et al., 2007; Pačuta et al., 2018; Sinervo et al., 2000). Animals with high level of boldness (prone to undertake risky behav-iors) and low level of neophobia may explore an unfa-miliar space (novel environment) more likely and faster (Damas-Moreira et al., 2020; White et al., 2013). On the contrary, reluctant to explore a novel environment (freezing), shy animals may avoid exploring unfamiliar space, reducing probability to forage under high preda-tion risk (Evans et al., 2019). Consequently, some indi-viduals can familiarize with novelty much faster than the others on exposure to a new environment and over short time intervals, differing in their locomotion and freezing behaviors (Pačuta et al., 2018; Sreelatha et al., 2021). Even though the locomotion of lizards is strongly dependent on environmental temperature (Braña, 1991; Paladino, 1985), they may develop alternative strategies corresponding to these behaviors. An interplay between the alternative behavioral strategies and morphological, physiological and life history traits might eventually affect the variable fitness optima of color morphs (Pérez i de Lanuza and Font, 2015; Sacchi et al., 2017, 2018; Sinervo and Svensson, 2002).The Common wall lizard, Podarcis muralis (Laurenti, 1768), exhibits ventral color polymorphism character-ized by three pure color morphs (yellow, white, orange) and two intermediate (i.e., mosaic) morphs (yellow-orange and white-orange; Aguilar et al., 2022; Pérez i de Lanuza et al., 2013, 2018; Scali et al., 2013). Previous studies have identified cases where these color morphs use alternative resources, optimizing their fitness to local adaptive optima (Abalos et al., 2016; Coladonato et al., 2020). In the Eastern Pyrenees region, the local frequen-cies of yellow and yellow-orange morphs seem to be constrained by climatic factors, whereas white, orange and white-orange morphs are widely distributed over species range (Pérez i de Lanuza et al., 2018). At smaller spatial scales, orange animals prefer more humid micro-habitats than other morphs (Pérez i de Lanuza and Car-retero, 2018; Scali et al., 2016). The local diversity of the morphs can also depend on the intensity of sexual selec-tion (i.e., sex-ratio, emerging rare yellow and yellow-orange morphs in male-biased populations; Pérez i de Lanuza et al., 2017). Thus, the color polymorphism with-in populations of P. muralis appears to be locally main-tained by a combination of environmentally depend-ent and sexual selections, showing a great geographical dependence (Calsbeek et al., 2010; Galeotti et al., 2013; Pérez i de Lanuza et al., 2013, 2018; Pérez i de Lanuza and Carretero, 2018; Sacchi et al., 2007).In a previous study, focused on the behavioral strat-egies of the three pure morphs of P. muralis fromVa l d’Aran (central Pyrenees), we found that the morphs dif-fered in locomotion and freezing behavior, and showed significant changes throughout a 15-minute experimen-tal trial (Sreelatha et al., 2021). Yellow animals showed a risk sensitive strategy, by exploring the novel envi-ronment quickly and gradually decreasing the locomo-tion over time, moving to potentially safe areas. Orange and white lizards showed a risk aversive strategy, with the opposite pattern. Such variation in locomotion was repeatable over consecutive experimental trials (Sreelatha et al., 2021).Here, we extend our approach by testing if P. muralis color morphs differ in behavioral strategies in populations from an independent, more anthropized area within the same region. We quantified behavioral traits of the several morphs by exposing them to a novel environ-ment. By doing so, we aimed at generalizing our previous findings, which suggested behavioral differences among morphs. Additionally, we also explore eventual maladap-tive behaviors in the mixed morphs, which are often less frequent in natural populations than expected, assuming random pairing (Pérez i de Lanuza et al., 2013).

DOI: https://doi.org/10.36253/a_h-14610

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