?Food habits of the Yacare caiman (Caiman yacare) in Corrientes provinces

SIMONCINI; IMHOF; ADJAD; PIÑA

Congreso; Congreso Internacional ?XXIV Working Meeting Crocodiles Specialist Group ? UICN; 2016

Food habits of the Yacare caiman (Caiman yacare) in Corrientes province,Argentina.Felipe Adjad 1, 2 , Alba Imhof 1 , Melina Simoncini 1,2 , and Carlos I. Piña 1,2 .1 Proyecto Yacaré - Laboratorio de Zoología Aplicada: Anexo Vertebrados (FHUC - UNL / MASPyMA),Santa Fe, Santa Fe, Argentina (losadjad@gmail.com; albaimhof@hotmail.com); 2 CICyTTP-UAdER-Prov Entre Ríos-CONICET. FCyT, Dr. Materi y España - Entre Ríos, Diamante, Argentina.(melinasimoncini22@yahoo.com.ar; cidcarlos@infoaire.com.ar).Caiman yacare (Yacare caiman) and Caiman latirostris (Broad- snouted caiman) are the Crocodylia species present in Argentina. There are studies about the diet of C. latirostris in Brazil and Uruguay,those studies detail the different types of prey that were found in stomach contents, mostly insects,crustaceans, and mollusks. In Argentina, little is known the trophic ecology of these animals, and the only record was a study that describes the type of prey for both species. The aim of our study was to examine stomach contents of C. yacare to know prey items and they sizes, and if there was any ontogenetic change. Data were collected in 6 lakes in Corrientes province (Argentina). We obtained 47 stomach contents of C. yacare (individuals between 15 to 119 cm snout-vent length), samplings were conducted at the beginning of spring. The most important preys were Insects (Coleoptera, Orthoptera,Odonata and Hemiptera), mollusks (Pomacea), freshwater crustaceans (Pseudopalaemon andTrichodactylus). Vertebrates (reptiles, fish and birds) were found less frequently. We found no evidence that prey items of the caiman change substantially as they get bigger, but we found that as caiman get bigger, insects consumption decreases. Caiman that consumed more mollusks alsoconsumed more crustaceans. Class I caiman did not consume vertebrates, Class II consumed squamata and other caiman, and once they get bigger consume birds. We conclude that as caiman get bigger they keep using previous food items, but amplify the trophic niche.