Morph-specific seasonal variation of aggressive behaviour in a polymorphic lizard species

PeerJ

article

Alan Jioele Coladonato¹  Marco Mangiacotti¹  Stefano Scali²  Marco A. L. Zuffi³  Carlotta Pasquariello¹  Cristian Matellini¹  Simone Buratti¹  Mara Battaiola¹  Roberto Sacchi¹ 

[1] Department of Earth and Environmental Sciences, University of Pavia;Museo di Storia Naturale di Milano;Museo di Storia Naturale dell’Università di Pisa

关键词: Colour polymorphism;    Aggressive behaviour;    Podarcis muralis;    Seasonal variation;    Alternative strategies;    Mirror test;   

DOI  :  10.7717/peerj.10268

学科分类：社会科学、人文和艺术（综合）

来源: Inra

【 摘 要 】

The persistence of colour polymorphism (CP) within a given population is generally associated with the coexistence of alternative reproductive strategies, each one involving specific trade-offs among behavioural, morphological, physiological, and other life histories. Common wall lizard (Podarcis muralis), is a medium-sized diurnal lizard, showing CP in three main colours (yellow, white, and red) on throat and belly, and a morph-specific pattern for both immunocompetence and seasonal variation of T levels. Yellow males show low stamina with high plasma T levels at the beginning of the season, while white males show high stamina with a higher plasma T levels at the end of the season. We hypothesised the presence of two strategies: a risky one, characterised by high aggressiveness played by yellow-morph, and a conservative one by white morph with low aggressiveness. Thus, we tested the aggressive response to conspecifics of yellow and white morphs using a mirror inserted into their cage, mimicking an intrusion of a stranger in their territories, throughout the breeding season (from April to July, 117 trials). We considered three types of aggressive response, with different levels of aggressiveness: (i) bite against the image reflected in the mirror, (ii) seconds spent by the individuals into the half mirrored cage, and (iii) number of times the lizard entered the half mirrored cage. We also considered the number of tongue flicking as explorative behaviour variable. All lizards were tested after a period of acclimatisation to the captivity conditions. Results demonstrate that yellow males showed a higher aggressive response in the early season and a decrease aggressive response towards the end, whereas white males showed an opposite pattern.

【 授权许可】

CC BY