This is the first detailed description of ontogenetic (during development) color changes (OCCs) in the ventral and ventrolateral coloration of Podarcis muralis. The research has analyzed the ultraviolet (UV) component of color with reflectance spectrophotometry, from birth to the first year of life. "Although the colors of the adults of this species were known, there was no characterization of the coloration of the juveniles and how it develops," says Javier Ábalos, first signatory of the article and postdoctoral researcher of the Department of Ethology of the Cavanilles Institute of Biodiversity and Evolutionary Biology (ICBiBE), located in the scientific-academic area of the Science Park of the University of Valencia (PCUV).
Researchers have identified in baby lizards a type of target that was previously unknown to the species (target with ultraviolet-UV reflectance), significantly different from adult target (target without UV), which clearly distinguishes them from adults in the eyes of other lizards. In addition, a delay in the acquisition of blue-UV spots on the flanks is documented for the first time with respect to the yellow, orange or white colouration without UV of the throat and belly, and marked differences between the sexes.
"Although predation often explains juvenile chromatic changes, in P. muralis it is unlikely, since the variation mainly affects ventral coloration, normally hidden. More plausible is a role in intra-specific communication, given that adults exhibit throat and flanks in social interactions", Guillem Pérez i de Lanuza, ICBiBE researcher
The research, in which also participate Alicia Bartolomé, Guillem Pérez i de Lanuza and Enrique Font (ICBiBE), highlights that these colors probably play a role in social communication. Calves are born with an apparently white belly and throat. The development of ventral coloration and lateral blue-UV spots occurs asynchronously and with differences between the sexes.
"Although predation often explains juvenile chromatic changes, in P. muralis it is unlikely, since the variation mainly affects ventral coloration, normally hidden. More plausible is a role in intra-specific communication, given that adults exhibit the throat and flanks in social interactions", explains Guillem Pérez i de Lanuza. "These changes can help adults to recognize young people and moderate their aggressiveness towards them, favoring the coexistence of adults and youth," says Javier Ábalos.
The work has received a Margarita Salas Grant to Javier Ábalos (ref. MS21-053), another FPU Grant to Alicia Bartolomé (ref. FPU18/04021), a FCT Grant (ref. SFRH/BPD/94582/2013) and a Juan de la Cierva-Incorporation Grant (ref. IJC2018-035319-I) to Guillem Pérez de Lanuza, and the project AICO/2021/113 of the Council of Innovation, Universities, Science and Digital Society and the project PID2019 104721GB I00 of the Ministry of Science and Innovation. Thomas Deruelles (Centre National de la Recherche Scientifique in France and Charles Sturt University in Australia) also participated in the work.
Source: UV News