Density and population size of mammals introduced on a land-bridge island in southeastern Brazil
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The introduction of alien species is one of the main threats to the conservation of native species, especially in island ecosystems. Here, we report on the population growth of 15 species of mammals introduced in 1983 on the island of Anchieta, an 828 ha land-bridge island in southeastern Brazil. We estimated the density of mammals through 296 km of line transect census. Five species introduced became extinct (coypu, brocket deer, six-banded armadillo, nine-banded armadillo, maned three-toed sloth); six became over-abundant (marmoset, coati, agouti, seven-banded armadillo, and capybara); one has a stable population (capuchin monkey). Anchieta Island has the highest density of mammals in the entire Atlantic forest (486.77 ind/km2), especially nest predators (232.83 ind/km2) and herbivores (253.58 ind/km2). Agoutis (Dasyprocta spp.) and marmosets (Callithrix penicillata) were, by far, the species with the highest population growth. The high density of mammals in this island may have strong consequences for plant recruitment and bird diversity.
KeywordsDistance sampling Exotic species Herbivores Line transect Nest predation
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We would like to thank FAPESP (Project Biota 2001/14463-5), the International Foundation for Science (IFS), conservação Internacional (Brasil) and Idea Wild for the financial support. We are also grateful to the Instituto Florestal for the permission to work on Anchieta Island. R. Bueno, M. Soares and R. M. Marques for invaluable help in the field work. MG is a CNPq research fellow and RSB received a research grant from PIBIC-CNPq.
- Buckland ST, Anderson DR, Burnham KP, Laake JL (1993) Distance sampling: estimating abundance of biological populations. Chapman and Hall, New YorkGoogle Scholar
- Buckland ST, Anderson DR, Burnham KP, Laake JL, Borchers DL, Thomas L (2001) Introduction to distance sampling. Oxford University Press, Oxford, p␣432Google Scholar
- Chiarello AG (2000) Density and population size of mammals in remnants of Brazilian Atlantic forest. Conserv Biol 14: 1649–1657Google Scholar
- Cruz O (1974) A serra do mar e o litoral na área de Caraguatatuba, SP – Contribuição à geomorfologia litorânea e tropical. Série Teses e Monografias – IGEOG 11:1–181Google Scholar
- Cullen L Jr, Bodmer RE, Valladares-Padua C (2001) Ecological consequenses of hunting in Atlantic forest patches, São Paulo, Brazil. Oryx 35:137–144Google Scholar
- Edington JE, Edington MA (1979) Ecology and environmental planning. Chapman and Hall, London, p 246Google Scholar
- Emmel CT (1976) Population biology. Chapman and Hall Ltd, London, p 371Google Scholar
- Fadini RF (2005) Limitações bióticas afetando o reclutamento da palmeira Euterpe edulis em uma ilha continental da mata Atâlntica Dissertação de mestrado em Ciências Biológicas em BotânicaGoogle Scholar
- Furlan JD (1998) Modelagem de objetos através da UML – the Unified Modeling Language. Makron Books, São PauloGoogle Scholar
- Glanz WE (1982) The terrestrial mammal fauna of Barro Colorado Island: censures and long-term changes. In: Leigh EG Jr, Rand AS, Windson DM (eds) The ecology of a tropical forest: seasonal rhythms and long-term changes. Smithsonian Institution Press, Washington, D.C, pp 455 – 468Google Scholar
- Guillaumon JR et al (1989) Plano de Manejo do Parque Estadual da Ilha Anchieta. IF – Série Registros, São Paulo, p 103Google Scholar
- Péres AK Jr (2003) Sistemática e Conservação de Lagartos do Gênero Tupinambis (Squamata, Teiidae). Tese de Doutorado, Departamento de Zoologia, Universidade de Brasília, p 193Google Scholar
- Quammen D (1996) The song of the Dodo. Island biogeography in an age of extinctions. Pimlico, LondresGoogle Scholar