Aspectos da ecologia reprodutiva de Podocnemis expansa, Podocnemis sextuberculata e Podocnemis unifilis (Testudines, Podocnemididae) na Reserva Biológica do Abufari, Amazonas, Brasil.

Abstract

The present dissertation investigated about behavior microhabitat selection by tartaruga (Podocnemis expansa), iaçá (P. sextuberculata) and tracajá (P. unifilis) in Abufari Biological Reserve, Amazonas. Were monitored the turtles reproductive periods (August - December) of the 1998-2004 years. The first specie at nesting was iaçá, after tartaruga and last tracajá. The three species studied have distinct patterns in nest site selection, P. expansa have nesting gregarious behavior in the height beach portions (above 400 cm) and also P. sextuberculata nesting in sites with high elevation in the same place, but its nest are disperses around the beach; both species present specializase nesting selection behavior because its nesting mainly in sand beach. Pattern of selection of microhabitat was not observed in the nesting site for P. unifilis, showing generalist nesting selection behavior. The main cause of lost nest of P. expansa is excavation of nest by others females lastes nidificated. Predation caused by lizard Tupinambis sp. and bird Coragyps atratus were the main factor of nest losses of P. sextuberculata and P. unifilis in Abufari beach. The water inundation by Purus River too causes nest loss, specailly wich are found below of 100 cm height. The mean size and weight of tartarugas, tracajás and iaçás that nesting in Abufari beach were 709 mm, 268 mm and 424 mm, weight 25 kg, 2.2 kg and 6.5 kg, respectively. Was observed that there are difference in size females of tartarugas between years studies (P<0.05), but was not difference between others species (P>0.05). The mean clutch size of tartaruga, iaçá and tracajá was 107, 13 and 21 eggs/nest. The clutch size of tartarugas was different between years of studies (P<0.05), but was not different to iaçás and tracajás (P>0.05). The mean hatchling success and fertility of the three species was surrounding 80%. Hatchling length and weight are relationship in all species studies. The production of tartarugas hatchling in Abufari beach is one majors of the Amazon State, with mean 180,000 hatchlings/years.