PREFERENCIA ALIMENTAR DAS AVES FRUGÍVORAS DE UM FRAGMENTO DE FLORESTA ESTACIONAL SEMIDECÍDUA SECUNDÁRIA, SÃO PAULO, BRASIL Érica Hasui ^ Elizabeth Höfling ^ ABSTRACT FOOD PREFERENCE OF THE FRUGIVOROUS BIRDS IN A FRAGMENT OF SEMIDECIDUOUS FOREST, SÃO PAULO, BRAZIL. Over aperiod of August 1991 through July 1993, in a fragment of 102,1 10 m^ of semideciduous forest, at the Cidade Universitária Armando de Salles Oliveira, São Paulo, Brazil, 69 species of omithochoric plants were found from which 46 were eaten by birds, verified by field observations and analysis of feces. Visits were more frequent to Ficus microcarpa Vahl, Alchornea sidifolia Muell. Arg., Schinus terebinthifolius Raddi, Guettarda viburnoides Cham. & Schlecht, and Prunus sellowii Kohene. Fruit selection by birds was not related to the degree of importance of these plant species in the community, but to feeding preference of the birds, influenced by the time of fruit bearing and also by structural and morphological features of the fruit, such as horizontal distribution and stratification, morphological type, colour as well as size of the fruit and the seed. The pattem of fruit selection varied according to the species of fruit-eating birds, so that there is preference for certain types of fruit. These variations ended up with the selection of the main potential fruit eating dispersers for each plant. KEYWORDS. Frugivory, Birds, Frugivorous birds, Omithochoric species. INTRODUÇÃO Nas florestas tropicais existe uma tendência à oferta constante de alimento, que varia quantitativa e qualitativamente, de acordo com as limitações climáticas (Snow, 1981; Wheelwright, 1985). Nos casos onde as plantas são semelhantes morfológica e ecologicamente, deve haver competição interespecífica pelos agentes dispersores. Assim, a pressão seletiva deve ter sido direcionada no sentido de alterar a época de frutificação das plantas, de modo a estimular o mínimo de sobreposição entre elas quanto a este aspecto (Snow, 1965). 1. Faculdade de Ciências Exatas e Experimentais, Universidade Mackenzie, Rua Itambé n° 45, CEP 01239-902, São Paulo. Brasil. 2. Departamento de Zoologia, Instituto de Biociências, Universidade de São Paulo: CR 1 1 461, CEP 05422-970. São Paulo, Brasil. Iheringia, Sér. Zool., Porto Alegre, (84): 43-64, 20 maio 1998
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