Full text
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| Author(s): |
Fernanda Alves de Amorim
Total Authors: 1
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| Document type: | Master's Dissertation |
| Press: | São Paulo. |
| Institution: | Universidade de São Paulo (USP). Instituto de Biociências (IBIOC/SB) |
| Defense date: | 2014-11-11 |
| Examining board members: |
Luis Fábio Silveira;
Christine Steiner São Bernardo;
Leonardo Liberali Wedekin
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| Advisor: | Luis Fábio Silveira |
| Abstract | |
The Red-billed Curassow was formerly found throughout the lowland Brazilian Atlantic Forest but is now extinct across most of its former range due to habitat loss and hunting pressure. Althought classified as globally threatened, there is still a chronic lack of information on Red-billed Curassows\' biology hindering efforts to mitigate the impacts of anthropogenic threats. We investigated population size and habitat relations of Red-billed Curassows at Vale Nature Reserve (VNR) using line transect and presence/absence method. Line transects results showed a male skewed sex ratio that appeared to be related to different behavivour between sexes as we recorded a low number of females. To evaluate any bias in the estimates of sex ratio from line transect we used data from a camera trap survey designed to monitor jaguars at the reserve. Camera trap data confirmed the existence of a male skewed sex ratio in the population but less pronounced than the one found on line transects, showing that different behavior between sexes affected our estimates. Using the sex ratio calculated with camera trap data we were able to estimate 1.6 individuals/Km2. The habitat assessment showed a positive relation of the Red-billed Curassow with taller forests and dense undergrowth. The abundance of snags, decaying log and leaf litter depth, negatively influenced Red-billed Curassows\' occurrence and appear to be related to its mainly frugivorous diet and low tolerance to habitat disturbances. Our study provides critical baseline information about an important population of Red-billed Curassows and will serve to guide management strategies and future reintroduction attempts. It also reveals that survey efforts must take into account sexual differences in behaviour to increase the reliability of modeled estimates. Failing to take these considerations into account may lead to misleading inferences from data, and impact management strategies for a seriously threatened species. (AU) | |
| FAPESP's process: | 12/08265-0 - Population density, social organization and habitat selection by the Red-billed Curassow, in the Reserva Natural Vale, Linhares, Espírito Santo |
| Grantee: | Fernanda Alves de Amorim |
| Support Opportunities: | Scholarships in Brazil - Master |