Ecologia e comportamento do Cuxiú-Preto (Chiropotes Satanas) na paisagem fragmentada da Amazônia Oriental. / The Ecology and Behaviour of the Black Bearded Saki (Chiropotes satanas) in the Fragmented Landscape of Eastern Amazonia

AUTOR(ES)
DATA DE PUBLICAÇÃO

2006

RESUMO

Bearded sakis are frugivores specialised for seed predation. The black bearded saki (Chiropotes satanas) is endemic to a densely populated and deforested area in eastern Amazonia in Brazil and is threatened with extinction. The principal objective of this study was to research the behaviour and ecology of two groups of black bearded sakis living under different degrees of habitat fragmentation, to understand how ecological parameters in these different settings influence behavioural strategies. In addition, the study aimed to identify factors that may limit the long-term viability of the black bearded saki and identify information that may contribute to conservation and management plans. The study took place on the right bank of the Tocantins River in the Tucuruí Reservoir, Pará State, Brazil (415 S, 4931 W). Two groups of bearded sakis were studied: one (denominated T4) in a large mainland fragment (1,300 ha - 39 members), and one on a small (19.4 ha - eight members) forested island. Twelve months behavioural sampling (1,153 observation hours) was undertaken using both scan and behaviour-sampling methodologies for 4 to 5 consecutive days per month per group. In addition to collecting activity budget data, all food resources were documented, daily routes plotted and intraspecies and interspecies social interactions recorded. Botanical transects (10 x 100 ha) covering one hectare at the T4 site and 0.5 hectare on the island were established, and a subsample of trees (≥ DAP 10cm) and lianas (≥ DAP 5 cm) marked and measured for a floristic inventory and phenological data collection which took place at 30-day intervals over 14 months. The two groups differed in all aspects of their behaviour and ecology. Time spent in different activities varied significantly between the groups. Moving (35.4%) comprised the largest proportion of annual budget in the T4 group, while the Island group devoted more time to feeding (30.0%). Social interactions accounted for a relatively large proportion of activity budget for both groups (T4 8.5%; Island 15.2%). Over the study, the two groups consumed a large number of different plant species (T4 173; Island 132; both groups 240) and their diets varied significantly in terms of items consumed and taxonomic composition. Both groups spent most of their time consuming seeds (T4 54.0%; Island 59.9%), however other items, including fruit pulp (T4 25.0%; Island 13.7%), flowers (T4 12.3%; Island 17.4%) and to a lesser extent pith and arthropods were also included in their diets. Members of the T4 group used an area of 98.6 ha and the island group, 17.2 ha. Use of space and daily path length (T4 4025 m 994 m; Island 2807 m 289 m) varied between groups and was linked in T4 group to the variation in group size throughout the year as a result of their complex fission-fusion sociality, the island group on the other hand was more cohesive. Variations in ecology and behaviour of the two groups were linked to differences in their respective habitats. The size of the sites was important but so too was the variation in the availability of food. Results from the floristic inventory revealed a greater diversity of different species on the T4 site, however important food species were either missing or available in varying amounts at both site. In addition to the intrinsic value of the knowledge of ecological characteristics of the bearded saki the detailed knowledge accumulated this study will help in the formulation of conservation action and management plans and in the identification of the factors which limit the long term viability of remaining populations in the fragmented landscapes of eastern Amazonia.

ASSUNTO(S)

seeds dispersal animal ecology cuxiú-preto (chiropotes satanas) sementes - dispersão primata - comportamento primates - ecology psicologia experimental primates behavior ecologia animal amazônia oriental ecological characteristics características ecológicas primata - ecologia black bearded saki (chiropotes satanas) oriental amazon

ACESSO AO ARTIGO

Documentos Relacionados