Site fidelity and movement of Chelonoidis carbonaria (Spix, 1824) (Testudinidae) in cocoa plantations in southeastern Brazil.

Red-footed Tortoises (Chelonoidis carbonaria Spix, 1824) raised as pets and voluntarily handed over to environmental officers by their owners or apprehended by officers represent a large contingent of animals that overfill triage centres in Brazil. There is no consensus on the fate of these animals, and their numbers continue growing. In this study, we evaluated the movement patterns of C. carbonaria originating from triage centres in areas of cocoa plantations and forest remnants to define their home range and dispersion. After 120 days of quarantine and acclimatisation, eight C. carbonaria adults were released and monitored via radio telemetry for 10 months. The radio transmitters of two individuals presented problems, and consequently, it was not possible to track these individuals. Five individuals remained in an area of 7.75 ha 10 months after release, avoiding contact with humans after the first three months. The greatest problems were the proximity of individuals to inhabited areas in the first three months after release, the death of two individuals, and the escape of one individual. After the experiment, the animals were sent back to the triage centre. Our results suggest that a proportion of the animals in the triage centres are able to survive in natural conditions. Considering their survival and fidelity to the release site, the translocation of animals described herein should be considered partially successful. However, if this measure is adopted, it must be preceded by studies of the animals' origins and by a rigorous genetic, sanitary and behavioural analysis of each individual.

Morphological variations and sexual dimorphism in Chelonoidis carbonaria (Spix, 1824) and Chelonoidis denticulata (Linnaeus, 1766) (Testudinidae).

Chelonoidis Dcarbonaria and C. denticulata are two tortoises which are widely distributed Brazil. Although they occur sympatrically in different areas, C. carbonaria prefers open areas, while C. denticulata chooses forest areas. Significant morphological variations can be observed in these species due to the fact that they occupy a vast and environmentally diverse area. Data on shell shape of captive individuals reveal important differences between the two species, mainly in the plastron scutes, carapace width, and head length. Variation in shape is greater in C. carbonaria than in C. denticulata, which may be associated to a more elaborate and complex mating ritual. The shell shape in C. denticulata is more elongated than in C. carbonaria due to ecological habits. These aspects lead to a greater restriction in shape, limiting variation and dimorphism. In C. carbonaria, the shell opening is larger than in C. denticulata, which affords greater variation in shape. A more elongated shell facilitates movements of C. denticulata in densely forested areas. Yet, this characteristic reduces shell opening, lessening the possibilities of variation in form.

Morphometric pattern in Caretta caretta (Linnaeus, 1758)(Cheloniidae) hatchlings from nests with different embryo development rates.

The geometric morphometric analysis of the shell of Caretta caretta hatchlings revealed that morphological variations may be related to incubation duration. Based on the overlapping of anatomical landmarks of the carapace and the plastron, it was possible to discriminate hatchlings from slow and fast developing clutches. Carapace and plastron of hatchlings from nests where incubation lasted less than 55 days are rounder as compared to the hatchlings from nests where incubation took 67 days. The differences observed in shell shape in terms of incubation duration were statistically significant, though carapace and plastron shape overlapping was observed in several individuals. Our results indicate that the incubation duration explains only a small part of the total variation in the shell shape as a whole. Yet, in spite of the low discriminant function coefficient, cross-validation tests indicated that 84.7% and 77.8% of the hatchlings were correctly categorised concerning the carapace and plastron, when the descriptive variable is incubation duration.

Nesting ecology of Podocnemis expansa (Schweigger, 1812) and Podocnemis unifilis (Troschel, 1848) (Testudines, Podocnemididae) in the Javaés River, Brazil.

Nest site has influence on incubation duration and hatching success of two Neotropical turtles, the giant Amazon River turtle (Podocnemis expansa) and yellow-spotted side-neck turtle (Podocnemis unifilis--'Tracajá'). The 2000 and 2001 nesting seasons have been monitored at the Javaés River in Bananal Island, Brazil. Although they nest on the same beaches, there is a separation of the nesting areas of P unifilis and P. expansa nests on the upper parts of the beach. The incubation duration for P. expansa is influenced by the nesting period, the height of the nest from the river, the clutch size, and the grain size in the site of the nest. Nests of Podocnemis expansa placed in coarse sediments have shorter incubation duration than those placed in finer sediments. The hatching success in P. expansa is influenced by grain size, incubation duration, and nesting period. The grain size is negatively correlated with hatching success, indicating that the nests situated in finer-grained sand have better chances of successful egg hatching than those in coarser-grained sand. Nests of the end of the reproductive season have lower hatching success and incubation duration than those at the start of the season. For P. unifilis, the nesting period and nest depth influence the incubation duration; moreover, the river dynamics significantly affect the hatching success. The oscillation of the river level and the moment of initial increase, the height of the nest from the river level, and the nesting period are all decisive components for hatching success. The results of this research show the importance of protecting areas with great geological diversity, wherein the features of the environment can affect the microenvironment of nests, with consequences on incubation duration and hatching success.