39 resultados para frugivores
Resumo:
Discute-se a importância do levantamento qualitativo e quantitativo da comunidade de aves da Fazenda Rio Claro (22°27'S, 48°51'W), Lençóis Paulista, para a avaliação de um fragmento de mata mesófila do interior de São Paulo. Tais levantamentos foram realizados entre agosto de 2001 a julho de 2002. Para o estudo quantitativo utilizou-se da metodologia de Pontos de Escuta. Foram analisados os índices de diversidade e de freqüência de ocorrência dessa comunidade, sendo as suas espécies organizadas tanto em função das categorias alimentares quanto sob o aspecto da ocupação do estrato vegetal. O levantamento qualitativo registrou 216 espécies. Já o quantitativo registrou 74 espécies em 761 contatos, com uma média de 12,7 contatos/amostra. O índice pontual de abundância (IPA) variou de 0,001 (um contato) a 0,07 (53 contatos); aquele da diversidade foi de H' = 3,10, mostrando um aumento significativo entre setembro e novembro; a eqüitatividade média no período foi de E = 0,95. Os insetívoros constituem quase a metade das espécies registradas no levantamento quantitativo (44,6%), seguido por frugívoros (24,9%), onívoros (16,4%), carnívoros (8,5%), nectarívoros (4,2%) e uma pequena proporção de detritívoros (1,4%). A categoria mais abundante no sub-bosque foi a de insetívoros, enquanto que os frugívoros foram os mais abundantes no solo e na copa. A comunidade de aves no fragmento estudado mostrou o mesmo padrão encontrado em outros fragmentos de mata mesófila de mesmo tamanho relativo. Algumas espécies ameaçadas foram encontradas na área de estudo.
Resumo:
The diet of the brown howler monkey Alouatta fusca in a 250 ha forest fragment in southeastern Brazil was studied for 42 consecutive months. The howlers were observed eating in 366 feeding records (one group or a monkey eating a single plant) of 52 plant species. Twenty three percent of the leaves and 52 % of the flowers in the howler's diet came from lianas. Eighteen fruit species were recorded as being dispersed by howlers and seeds of two liana species were eaten. In small forest fragments where most large specialized frugivores are absent howlers may be the main seed disperser of large fruits.
Resumo:
1. Until the late 1960s, Euterpe edulis was the most important edible palm species in the Brazilian markets. Since then, overharvesting of natural stands and the limited scope of plantations have caused the industry to shift to the multistemmed E, oleracea from the Amazon river estuary.2, As a result of the relocation of the industry, the structure of the palm harvesting industry has changed and illegal trade has continued to exploit the remaining natural stands of E, edulis.3, it is suggested that, to avoid the total harvesting of E. edulis and to achieve sustainable management of the palm heart, it will be necessary to diversify the local economy, create incentives for small land owners to improve their management practices, while keeping their competitiveness against the illegal trade, create the incentive of new sources of palm hearts and create a 'green stamping' For management palms.4, Transformation of the illegal structure of the palm heart industry is probably the only solution to avoid the total depletion of the wild stands of E. edulis.
Resumo:
Fruit-eating by fishes represents an ancient (perhaps Paleozoic) interaction increasingly regarded as important for seed dispersal (ichthyochory) in tropical and temperate ecosystems. Most of the more than 275 known frugivorous species belong to the mainly Neotropical Characiformes (pacus, piranhas) and Siluriformes (catfishes), but cypriniforms (carps, minnows) are more important in the Holarctic and Indomalayan regions. Frugivores are among the most abundant fishes in Neotropical floodplains where they eat the fruits of a wide variety of trees and shrubs. By consuming fruits, fishes gain access to rich sources of carbohydrates, lipids and proteins and act as either seed predators or seed dispersers. With their often high mobility, large size, and great longevity, fruit-eating fishes can play important roles as seed dispersers and exert strong influences on local plant-recruitment dynamics and regional biodiversity. Recent feeding experiments focused on seed traits after gut passage support the idea that fishes are major seed dispersers in floodplain and riparian forests. Overfishing, damming, deforestation and logging potentially diminish ichthyochory and require immediate attention to ameliorate their effects. Much exciting work remains in terms of fish and plant adaptations to ichthyochory, dispersal regimes involving fishes in different ecosystems, and increased use of nondestructive methods such as stomach lavage, stable isotopes, genetic analyses and radio transmitters to determine fish diets and movements. (C) 2011 Elsevier Masson SAS. All rights reserved.
Resumo:
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Resumo:
Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
Resumo:
In this study we report on the consumption of two syntopic Melastomataceae species by birds in a lower montane forest in Monte Verde, southeastern Brazil. The species of frugivores were identified and characterized by their methods of capture and consumption of fruits. We also provide information on abundance, phenology of plants and fruit characteristics of the two Melastomataceae species. The 13 observed species of birds formed two statistically distinct frugivorous groups with taxonomic and behavioral differences. Five of seven bird species that fed on L. aff. sublanata fruits belong to the subfamily Thraupinae and most fruits were mashed before swallowed. Four of the eight bird species that visited M. cinerascens belong to the subfamily Turdinae and all fruits were swallowed whole. Only two bird species were common visitors of both Melastomataceae species. Our findings show that fruits of the two Melastomataceae species with similar morphological characteristics were exploited differently by frugivorours birds.
Functional Redundancy and Complementarities of Seed Dispersal by the Last Neotropical Megafrugivores
Resumo:
Background: Functional redundancy has been debated largely in ecology and conservation, yet we lack detailed empirical studies on the roles of functionally similar species in ecosystem function. Large bodied frugivores may disperse similar plant species and have strong impact on plant recruitment in tropical forests. The two largest frugivores in the neotropics, tapirs (Tapirus terrestris) and muriquis (Brachyteles arachnoides) are potential candidates for functional redundancy on seed dispersal effectiveness. Here we provide a comparison of the quantitative, qualitative and spatial effects on seed dispersal by these megafrugivores in a continuous Brazilian Atlantic forest. Methodology/Principal Findings: We found a low overlap of plant species dispersed by both muriquis and tapirs. A group of 35 muriquis occupied an area of 850 ha and dispersed 5 times more plant species, and 13 times more seeds than 22 tapirs living in the same area. Muriquis dispersed 2.4 times more seeds in any random position than tapirs. This can be explained mainly because seed deposition by muriquis leaves less empty space than tapirs. However, tapirs are able to disperse larger seeds than muriquis and move them into sites not reached by primates, such as large forest gaps, open areas and fragments nearby. Based on published information we found 302 plant species that are dispersed by at least one of these megafrugivores in the Brazilian Atlantic forest. Conclusions/Significance: Our study showed that both megafrugivores play complementary rather than redundant roles as seed dispersers. Although tapirs disperse fewer seeds and species than muriquis, they disperse larger-seeded species and in places not used by primates. The selective extinction of these megafrugivores will change the spatial seed rain they generate and may have negative effects on the recruitment of several plant species, particularly those with large seeds that have muriquis and tapirs as the last living seed dispersers. © 2013 Bueno et al.
Resumo:
Local extinctions have cascading effects on ecosystem functions, yet little is known about the potential for the rapid evolutionary change of species in human-modified scenarios. We show that the functional extinction of large-gape seed dispersers in the Brazilian Atlantic forest is associated with the consistent reduction of the seed size of a keystone palm species. Among 22 palm populations, areas deprived of large avian frugivores for several decades present smaller seeds than nondefaunated forests, with negative consequences for palm regeneration. Coalescence and phenotypic selection models indicate that seed size reduction most likely occurred within the past 100 years, associated with human-driven fragmentation. The fast-paced defaunation of large vertebrates is most likely causing unprecedented changes in the evolutionary trajectories and community composition of tropical forests.
Resumo:
Mistletoes represent the best example of specialization in seed dispersal, with a reduced assemblage of dispersal agents. Specific dispersal requirements mediated by the specificity of seed deposition site have apparently led to the evolution of such close relationships between mistletoes and certain frugivores. Here, we provide evidences for another case of specialization involving epiphytic cacti in the genus Rhipsalis, and small Neotropical passerines Euphonia spp., which also act as the main seed dispersers of mistletoes in the family Viscaceae. With field observations, literature search, and observations on captive birds, we demonstrated that Rhipsalis have specific establishment requirements, and euphonias are the most effective dispersers of Rhipsalis seeds in both quantitative and qualitative aspects, potentially depositing seeds onto branches of host plants. We interpret the similar dispersal systems of Rhipsalis and Viscaceae mistletoes, which involve the same dispersal agents, similar fruit morphologies, and fruit chemistry as convergent adaptive strategies that enable seeds of both groups to reach adequate microsites for establishment in host branches. © 2013 by The Association for Tropical Biology and Conservation.
Resumo:
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Resumo:
Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
Resumo:
Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
Reproductive phenology and fruit production on a land bridge island in the brazilian atlantic forest
Resumo:
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Resumo:
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)