RHINELLA CF. ALTIPERUVIANA NEST MICRO-ENVIROMENT SELECTION: THE IMPORTANCE OF ABIOTIC VARIABLES IN A RIGUROSUS HABITAT.

ARAGON Y TRAVERSO, JUAN HÉCTOR; IRIBAS F; QUIROGA L; GORDILLO L; SANABRIA, EDUARDO A.

san juan

Congreso; XLI Reunión Científica Anual de la Sociedad de Biología de Cuyo; 2023

sociedad de biologia de cuyo

Rhinella cf. altiperuviana is a species of toadthat inhabits high-altitude environments within the Andes mountain range. Thesehabitats are characterized by extreme aridity and low temperatures, both ofwhich pose significant challenges to amphibian survival. Furthermore, thisspecies can inhabit areas with high salinity levels, adding yet anotherobstacle to its development. R. cf. altiperuviana constructs small nestsin shallow watercourses to deposit its eggs. Although this behavior is welldocumented, the effect on environmental variables within these nests andwhether their construction confers any advantages for the proper development ofthe species' eggs remains unknown. The Ancho river (-31.669612 W; -68.828903 S;1486 m.a.s.l.) was surveyed for nests containing eggs or tadpoles. Sevenenvironmental variables (pH, salinity, water depth, water temperature, watervelocity, vegetation, and soil granulometry) were measured inside these nestsand in another “nest-less” similar micro-habitat in a 50cm radius.Subsequently, logistic regressions were performed, with the presence of eggclutches as the response variable, incorporating all possible combinations ofthe measured variables while considering the order of their inclusion (n=511models). Based on Akaike Information Criterion (AIC) scores, the mostparsimonious model that best explained the presence of egg deposits of thespecies was selected. The best model included the variables of watertemperature and water velocity. These results suggest that the construction of nestshelps to create a warmer and quiet environment for the eggs incubation. Inconclusion, the built of nests by R. cf. altiperuviana could be anadaptation to the low Andean temperatures, and to the high velocity of themountain streams, in order to prevent damage on the gelatinous egg cords.