Timing of nest predation events during incubation of the Broad-snouted Caiman (Caiman latirostris)

PIERINI, S.; BAUSO J.; SIMONCINI, M.; SCARPA, L.; LARRIERA, A.; PIÑA, C. I.

Chetumal

Congreso; XXVI Working Meeting Crocodiles Specialist Group - UICN; 2022

Crocodiles Specialist Group - UICN

Inthe wild, nest predation is the primary cause of nest failure in Broad-snoutedCaiman (Caiman latirostris). We analyzedthe temporal occurrence -daily and monthly activity patterns- of nest predatorsduring egg incubation of C. latirostris.From December to March 2018-2019 and 2019-2020 we recorded activity patterns ofnest predators and nesting caiman females using camera-traps in 33 nests. Oursampling effort resulted in 4,531 camera-trap-nights and 3,164 independentrecords, 1,403 of these were from C.latirostris and 589 of animals representing risks to the nests. Mostof these records corresponded to four species: 49% to the Black-and-white Tegu(active between 6:46 and 19:20 h); 14.4% to the Capybara (not preying eggs, butdestroying nests when settling, active between 09:58 - 19:21h); 12.3% to the Crab-eating Fox (active between 06:00 - 11:14 h) and 7.2% tothe Southern Long-nosed Armadillo (active between 09:58 - 19:21 h). The Black-and-whiteTegu was the most frequent predator, explaining by the lower activity overlapwith Broad-snouted Caiman. Rarely, females defended nests and this occurredwhen Capybara and Black-and-white Tegu approached. Consideringmonthly activity, Tegu and Capybara predated and destroyed nests mainly inJanuary, while Armadillo frequented nests mainly in February. Since caimanfemales attend nests mostly at the beginning and end stages of the nestingseason, visitors commonly appear when nest attendance is reduced. Finally, Foxespredated nests in February and early March, when embryos are in advanceddevelopment stages. Results suggest that predators or nest destroyers would beopportunistic in visiting nests at specific times of caiman nesting season.