As a part of a management program we captured 39 capybaras (Hydrochoerus hydrochaeris) in an agroecosystem at the east central region of the State of São Paulo, Brazil from March 2001 to May 2002. Average adult male body mass was 54.1 ± 8.05 kg, and average adult female body mass was 62.0 ± 12.03 kg. Average juvenile male body mass was 23.0 ± 8.28 kg, and average juvenile female body mass was 26.7 ± 5.86 kg. Males and females presented a significant variation in the allometric relation between body mass and body length. Body mass and body length had a high correlation for both adult males and adult females. These results from capybaras in agroecosystem might be relevant for further management programs. Key words: Capybaras, body mass, body length, agroecosystem ResumoTrinta e nove capivaras (Hydrochoerus hydrochaeris) foram capturadas como parte de um programa de manejo em um agroecossistema na região centro-oeste do estado de São Paulo, de março de 2001 a maio de 2002. A massa corpórea média de machos adultos foi de 54.1 ± 8.05 kg, enquanto que de fêmeas adultas foi de 62.0 ± 12.03 kg. A massa corpórea média de machos jovens foi de 23.0 ± 8.28 kg, enquanto que de fêmeas jovens foi de 26.7 ± 5.86 kg. Machos e fêmeas apresentaram variação significativa na relação alométrica entre massa e comprimento corpóreos. Massa e comprimento corpóreos apresentaram alta correlação entre machos e fêmeas adultas. Estes resultados de capivaras em agroecossistemas podem ser importantes para futuros programas de manejo. Palavras-chave: capivara, massa corpórea, comprimento corpóreo, agroecossistemasBiota Neotropica v5(n1) -http://www.biotaneotropica.org.br/v5n1/pt/abstract?short-communication+BN03405012005

This study has been carried out at the central region of the Araguaia river on the border between the states of Goiás and Mato Grosso in the Brazilian Amazon Basin from September to December 2000. We recorded temperature fluctuation, clutch-size, incubation period and hatching success rate and hatchlings' sex ratio of five nests of Podocnemis expansa (Schweigger, 1812). Despite the relatively small sample size we infer that: a) nests of P. expansa in the central Araguaia river have a lower incubation temperature than nests located further south; however, incubation period is shorter, hatching success rate is lower and clutch-size is larger; b) Podocnemis expansa may present a female-male-female (FMF) pattern of temperature sex-determination (TSD); c) thermosensitive period of sex determination apparently occur at the last third of the incubation period; and, d) future studies should prioritize the relationship between temperature variation (i.e., range and cycle) and embryos development, survivorship and sex determination.

Podocnemis expansa (giant Amazon freshwater turtle) is the biggest freshwater turtle of South America. Like in other reptiles, the nest of P. expansa is a hole in the sand deep enough to avoid predators and extremes of temperature and humidity. However, nesting habitat selection in reptiles has effects on incubation success and on hatchlings. Female body-size is also related to the size and shape (i.e., form) of the nest, which might in theory be related to the female reproductive success. In this study we established allometric relationships between female body size and nest form. Fieldwork was carried out in nesting beaches of Araguaia and Crixás-Açu Rivers in Southern Amazon basin, Brazil, from September to December 2000. As a result, we can establish that nest form does not affect reproductive success in the species, but female body length is positively related to egg mass and clutch size.

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