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| Author(s): |
Marina Cobra Lacôrte
Total Authors: 1
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| Document type: | Master's Dissertation |
| Press: | Piracicaba. |
| Institution: | Universidade de São Paulo (USP). Escola Superior de Agricultura Luiz de Queiroz (ESALA/BC) |
| Defense date: | 2011-08-29 |
| Examining board members: |
Luciano Martins Verdade;
Carla Gheler Costa;
Marcio Roberto Costa Martins
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| Advisor: | Luciano Martins Verdade |
| Abstract | |
The expansion of agricultural land is recognized as one of the most significant anthropic alterations within the natural ecosystems. The conversion of forest into agricultural landscapes can change biotic interactions and natural resources availability. Alterations as such can have consequences in respect to the ecosystems services which are provided by natural forested areas. Mammals are responsible for ecological processes which are determinant for the forest maintenance and regeneration. Diet and habitat use are essential tools to determine species conservation status and how it deals with human-driven ecological changes. Hence within this context, two studies took place in disturbed areas in Southern São Paulo State, Brazil. Both studies involve middle-to large sized mammals in agricultural landscapes at the Alto Paranapanema watershed. In the first study, during the period of August 2008 to July 2010, every two months, the frequency of occurrence of middle-to large sized mammals was surveyed and recorded around streams of remaining gallery forests and artificial reservoirs originally built for cattle water supply. Both habitats are associated with new Eucalyptus plantations. As a result a total of 20 species were detected, 18 around artificial reservoirs and 17 in streams of gallery forests. However streams of gallery forests showed significantly higher species richness and abundance than artificial reservoirs. These results outline the importance of maintaining protected native vegetation areas by law in such landscapes. Results also suggest that the artificial reservoirs may increase habitat carrying capacity for middle- to large-sized mammals in such circumstances. The second study reports the diet and use of shelters by the neotropical otter (Lontra longicaudis) in a disturbed area. Otters are semi-aquatic carnivores with a potentially functional role in freshwater ecosystems. During the period from August 2008 to July 2009, otter scats were collected monthly at Paranapanema River. The shelters were described and graphically represented and the diet was quantified by analyzing 60 scats. The niche breadth analysis classifies L. longicaudis as a specialist species according to the trophic niche amplitude index (Levins index). The most common items identified were fishes from the Cichlidae and Loricariidae families, probably because of the habits of such species which makes them an easier prey. Such results stress the importance of freshwater ecosystems for the neotropical otter conservation. Results also suggest the adaptative potential of L. longicaudis and that some disturbed areas may be significant for this species conservation. Both studies emphasize the relevance of such altered ecosystems and it insertion requirement on protection and conservation initiatives towards biodiversity conservation. (AU) | |
| FAPESP's process: | 08/01798-8 - Diet and use of space by otters (Lontra longicaudis) in anthropic environments of Alto Paranapanema region, state of Sao Paulo |
| Grantee: | Marina Cobra Lacorte |
| Support Opportunities: | Scholarships in Brazil - Master |