Influence of Climatic Variables on Corporal Attributes of Adult Female Caiman and Their Relationship with Reproductive Success

LEIVA, PAMELA M.L.; LABAQUE, MARÍA CARLA; PIÑA, CARLOS I.; SIMONCINI, MELINA S.

South American Journal of Herpetology

Brazilian Society of Herpetology

Lugar: Sao Paulo; Año: 2023 vol. 28

Studies on crocodilians indicate that energy investment inreproduction is conditioned by prey availability, which is in turn affected byrainfall. Therefore, environmental variables may affect individual body condition(BC) and physiological condition (PC). We evaluated the influence of climatic factorson the BC and PC of wild reproductive female Caiman latirostris and their performancein different seasons. We found no relationship between female BC and climatic variables,which indicates that only females that have managed to overcome a minimum requiredBC can reproduce and suggests that the minimum BC is not fixed. Females with higherBC produced nests with greater hatching success, proving that if there is a minimumenergy threshold that triggers reproduction; once the threshold is surpassedthe excess energy may be invested in quality of progeny. We observed that as rainfallincreases in river headwaters in March–April, clutch size decreases, indicatingthat in years with lower rainfall, only larger females may reproduce. RegardingPC, muscle fatty acid (FA) indicated C18:2 has a strong association withminimum temperatures in September, suggesting that temperatures of the firstwarm months determine the availability of food. Also, variation in plasma FAare associated with precipitation in October and December, showing that precipitationinfluences diet and PC. We conclude that rainfall and minimum ambient temperaturesmodulate the reproduction of C. latirostris and the dynamics of the population asa whole. Also, BC is a useful indicator for evaluating reproductive performanceand PC is a useful indicator to evaluate nutritional status of populations.