Allochrony in the common Gecko (Tarentola mauritanica) as a behavioral syndrome: an ecological and genetic study

Link To Share This Poster: https://cdmcd.co/rMW4p3
Live Discussion Link: https://cdmcd.co/WkzLYJ

Claudio Pardo Sr., Giulia Simbula Sr., Riccardo Sortino Jr. and Leonardo Vignoli Sr., Sciences, Università Roma Tre, Rome, Italy, Adriana Bellati Sr., Ecological and Biological Sciences, Università della Tuscia, Viterbo, Italy

Background/Question/Methods
Phenological difference between temporally segregated individuals of the same species is recognized as a major driver of reproductive isolation and even speciation. Temporally shifted eco-ethological patterns between individuals may promote the evolution of behavioral syndromes, allowing individuals to access resources in different (adaptive) ways.
The research goal of the study is to investigate allochrony in a population of the Common Gecko (Tarentola mauritanica) where syntopic individuals exhibit variation in their activity levels, being exclusively diurnal or nocturnal by adopting both genetic and ecological approaches.
The genetic structure of the population was studied at 9 microsatellite DNA loci, while the ecological divergence was estimated by testing: the ability of diurnal vs nocturnal geckos to mimic the substrate (via Background Color Matching – BCM – test); morphological variation; activity levels after a six-months captivity period, when diurnal and nocturnal geckos were kept separated.
Diurnal and nocturnal geckos were sampled along stone walls within a protected area in Rome (Italy). Data were collected from July to November 2020 during the day (7:00 - 12:00) and at night (21:00 - 2:00). To ensure individual recognition, we took dorso-ventral pictures of individuals, marking them through non-toxic paint (short-term recognition) and toe-clipping (long-term recognition). Tail tips (N=90) were taken for genetic analyses. For BCM test, 9 geckos per group (N=18) experienced two backgrounds (white/black), in presence/absence of light for one hour. At the end of exposure, each animal was photographed under standard light conditions. Luminance and saturation of the gecko’s back surface were measured. Phenology was assessed individually via 24/7 video surveillance for four weeks after the captivity period.

Results/Conclusions
Diurnal geckos did not differ from nocturnal ones at microsatellite loci, but morphological (diurnal geckos were larger than nocturnal ones) and phenological differences were significant between the two groups, thus showing that activity patterns were in some way individually fixed. Diurnal individuals showed greater overall luminance and lighter saturated colour than nocturnal ones, although the two groups did not show differences in colour adaptability, suggesting that differences in the absolute values of luminance and saturation are due to the structure of the integument shared by individuals.
The results obtained contribute to shed light on the medium-long term consequences of a behavioral syndrome matching clear temporal segregation. The observed divergence between the two temporally segregated groups accounted for multiple characters probably related to a micro-evolutionary process worthy of further deepening to address mechanisms underlying the behavioral syndrome.