Food habits of the Yacare caiman (Caiman yacare) in Corrientes province, Argentina.

ADJAD, F.; IMHOF, A; SIMONCINI, M.; PIÑA, C. I.

Skukuza

Congreso; 24th Working meeting Crocodile Specialist Group/UICN; 2016

Internationa Union Conservation of Nature/Crocodile Specialist Group

Caimanyacare (Yacare caiman) and Caiman latirostris (Broad- snoutedcaiman) are the Crocodylia species present in Argentina. There are studies aboutthe diet of C. latirostris in Braziland Uruguay, those studies detail the different types of prey that were found instomach contents, mostly insects, crustaceans, and mollusks. In Argentina,little is known the trophic ecology of these animals, and the only record was astudy that describes the type of prey for both species. The aim of our studywas to examine stomach contents of C.yacare to know prey items and they sizes, and ifthere was any ontogenetic change. Data were collected in 6 lakes inCorrientes province (Argentina). We obtained 47 stomach contents of  C.yacare (individuals between 15 to 119 cm snout-vent length), samplings wereconducted at the beginning of spring. The most important preys were Insects(Coleoptera, Orthoptera, Odonata and Hemiptera), mollusks (Pomacea), freshwater crustaceans (Pseudopalaemon and Trichodactylus).Vertebrates (reptiles, fish and birds) were found less frequently. We found noevidence that prey items of the caiman change substantially as they get bigger,but we found that as caiman get bigger, insects consumption decreases. Caimanthat consumed more mollusks also consumed more crustaceans. Class I caiman didnot consume vertebrates, Class II consumed squamata and other caiman, and oncethey get bigger consume birds. We conclude that as caiman get bigger they keepusing previous food items, but amplify the trophic niche.