PADRÕES DE MOVIMENTO, USO DE MICROHÁBITAT E DIETA DO JACARÉ- PAGUÁ, PALEOSUCHUS PALPEBROSUS(CROCODILIA: ALLIGATORIDAE), EM UMA FLORESTA DE PALEOVÁRZEA AO SUL DO RIO SOLIMÕES, AMAZÔNIA CENTRAL, BRASIL

AUTOR(ES)
DATA DE PUBLICAÇÃO

2007

RESUMO

Survey based on nocturnal counts of Paleosuchus palpebrosus along dry and rainy season were made in flooded forest areas, streams and pounds in the edge of the highway BR-319, kilometer 80, approximately 100 km south of Manaus in the municipal district of Castanho - Central Amazon, for determination of movement patterns, microhabitat use and diet of the species. P. palpebrosus was registered in flooded forest areas, ponds, pastures, and at low numbers, in the streams. The number of P. palpebrosus found varied between hidric periods, but trend of migrations between habitats were not identified. The size structure of P. palpebrosus was estimated based on the average number of caimans registered every month and the estimated size of their heads. The structure was dominated by median-sized individuals. The microhabitat availability was quantified in the flooded areas and ponds, in the wet and dry seasons. In flooded areas and ponds, the number of individuals of P. palpebrosus that used open water were less than expected. In the flooded areas, in the dry season, P. palpebrosus used litter banks, branches and wood debris with higher frequency than expected, based in the microhabitat availability. There was no relation between physical and chemical variables and the occurrence of P. paleosuchus in 16 pounds. The movement of six individuals of dwarf caiman (three females and three males) was monitored with tracking reel, for 24-hour period, and most of the individuals used small areas close to the water body. Stomach flushing was done in 42 captured individuals of P. palpebrosus. Stomach contents were grouped into five categories: terrestrial vertebrates (mammals, birds, reptiles and frogs), fish, terrestrial invertebrates (spiders and insects), crustaceans (crabs and shrimps) and snails. The diet of P. palpebrosus was composed mainly by terrestrial invertebrates, with a 79% occurrence. Terrestrial vertebrates represented 19% of records. Snails had been found with bigger ratio in small individuals, while terrestrial fish and vertebrates had been consumed by individuals of almost all sizes. The sizes of the undigested prey were estimated by the target-size index, and the diet of the investigated individuals was composed mainly of small sized prey, the size of the ingested prey was not related with the caiman size. The presence of another three caiman species was registered (P. trigonatus, Melanosuchus niger e Caiman crocodilus). M. niger was registered in flooded forest areas in the rainy season. Few P. trigonatus have been recorded in the dry season using microhabitats of P. palpebrosus. C. crocodilus was found during all the surveys in pounds. In the rainy season, it was recorded in flooded areas sharing habitat with P. palpebrosus. Evidences of trends on seasonal migrations between habitats for C. crocodilus were found.

ASSUNTO(S)

densidade relativa uso de microhábitat padrões de movimento composição da dieta estrutura de tamanhos ecologia

ACESSO AO ARTIGO

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