Psittacids are important pre-dispersal seed predators. However, little is known about the parameters that may determine seed predation rates by these birds, such as plants' characteristics and microhabitat. Eriotheca gracilipes (Bombacaceae) is a semi-deciduous tree widely distributed in the Brazilian cerrado. The fruits are dehiscent pods and the seeds are wind-dispersed. Some individuals lose their leaves during the fruiting season, getting very conspicuous. Here we tested the hypothesis that the absence of leaves in E. gracilipes during the fruiting season may increase pre-dispersal seed predation by psittacids. We also tested the hypotheses that (1) seed predation intensity increases with increasing plant size and (2) number of fruits, (3) seed predation decreases with the increasing number of conspecific plants in a range of 15 m, and (4) seed predation intensity is lower in plants with higher vegetation cover over their crowns. The small parakeet Brotogeris versicolurus was the only species observed preying upon the seeds of E. gracilipes. The percentage of fruits damaged by the parakeets ranged from 0 to 100% (66.98 ± 43.11%, n = 72) among the different plants. Our data give weak support to the hypothesis that the absence of leaves may facilitate plants and/or fruits detection by the parakeets. However, seed predation intensity was significantly affected by crop size. The hypothesis that conspecific fruiting plants surrounding the studied individuals may reduce predation rate was not supported. Nevertheless, trees without higher vegetation cover over their crowns were significantly affected by increased seed predation. This suggests that seed predation by parakeets can be a potential selective factor influencing fruit crop sizes in E. gracilipes. © 2007 Elsevier Masson SAS. All rights reserved.332240245Barros, Y.B., 1995. Biologia comportamental de Forpus xanthopterygius Spix (1824)-(Aves-Psittacidae): alimentação e reprodução. Master thesis. Universidade Estadual Paulista, BrazilBenkman, C.W., Holimon, W.C., Smith, J.W., The influence of a competitor on the geographic mosaic of coevolution between crossbills and lodgepole pine (2001) Evolution, 55, pp. 282-294Benkman, C.W., Parchman, T.L., Flavis, A., Siepielski, A.M., Reciprocal selection causes a coevolutionary arms race between crossbills and lodgepole pine (2003) Am. Nat., 162, pp. 182-194Biere, A., Honders, S., Impact of flowering phenology of Silene alba and S. dioica on susceptibility to fungal infection and seed predation (1996) Oikos, 77, pp. 467-480Brody, A.K., Oviposition choices by a pre-dispersal seed predator (Hylemya sp.) I. Correspondence with hummingbird pollinators, and the role of plant size, density and floral morphology (1992) Oecologia, 91, pp. 56-62Brody, A.K., Mitchell, R.J., Effects of experimental manipulation of inflorescence size on pollination and pre-dispersal seed predation in the hummingbird-pollinated plant Ipomopsis aggregata (1997) Oecologia, 110, pp. 86-93Cavalcanti, R.B., Conservation of birds in the cerrado of central Brazil (1988) Ecology and Conservation of Grassland Birds, 7, pp. 59-66. , Goriup P.D. (Ed), ICBP Technical Publication, CambridgeCoates-Estrada, R., Estrada, A., Meritt Jr., D., Foraging by parrots (Amazona autumnalis) on fruits of Stemmadenia donnell-smithii (Apocinaceae) in the tropical rain forest of Los Tuxtlas, Mexico (1993) J. Trop. Ecol., 9, pp. 121-124Collar, N.J., Juniper, A.T., Dimensions and causes of parrots conservation crisis (1992) New World Parrots in Crisis, pp. 1-23. , Beissinger S.R., and Snyder N.F.R. (Eds), Smithsonian Institute Press, WashingtonDownhower, J.F., Racine, C.H., Darwin's finches and Croton scouleri: an analysis of the consequences of seed predation (1976) Biotropica, 8, pp. 66-70Eiten, G., The cerrado vegetation of Brazil (1972) Bot. Rev., 38, pp. 201-341Eiten, G., Vegetation of Brasília (1984) Phytocoenologia, 12, pp. 271-292Fenner, M., Cresswell, J.E., Hurley, R.A., Baldwin, T., Relationship between capitulum size and pre-dispersal seed predation by insect larvae in common Asteraceae (2002) Oecologia, 130, pp. 72-77Forget, P.M., Kitajima, K., Foster, R.B., Pre- and post-dispersal seed predation in Tachigali versicolor (Caesalpiniaceae): effects of timing of fruiting and variation among trees (1999) J. Trop. Ecol., 15, pp. 61-81Francisco, M.R., Lunardi, V.O., Galetti, M., Massive seed predation of Pseudobombax grandiflorum (Bombacaceae) by parakeets Brotogeris versicolurus (Psittacidae) in a forest fragment in Brazil (2002) Biotropica, 34, pp. 613-615Galetti, M., Diet of the Scaly-headed parrot (Pionus maximiliani) in a semideciduous forest in southeastern Brazil (1993) Biotropica, 25, pp. 419-425Galetti, M., Seasonal abundance and feeding ecology of parrots and parakeets in a lowland Atlantic forest of Brazil (1997) Ararajuba, 5, pp. 115-126Galetti, M., Rodrigues, M., Comparative seed predation on pods by parrots in Brazil (1992) Biotropica, 24, pp. 222-224Greig, N., Predispersal seed predation on five Piper species in tropical rainforest (1993) Oecologia, 93, pp. 412-420Harms, K.E., Wright, S.J., Calderon, O., Hernandez, A., Herre, E.A., Pervasive density-dependent recruitment enhances seedling diversity in a tropical forest (2000) Nature, 404, pp. 493-495Hemborg, A.M., Després, L., Oviposition by mutualistic seed parasitic pollinators and its effects on annual fitness of single and multi-flowered host plants (1999) Oecologia, 120, pp. 427-436Higgins, M.L., Intensity of seed predation on Brosimum utile by Mealy parrots (Amazona farinosa) (1979) Biotropica, 11, p. 80Howe, H.F., Monkey dispersal and waste of a neotropical fruit (1980) Ecology, 61, pp. 944-959Hulme, P.E., Post-dispersal seed predation: consequences for plant demography and evolution (1998) Perspect. Plant Ecol. Evol. Syst., 1, pp. 32-46Hulme, P.E., Benkman, C.W., Granivory (2002) Plant-Animal Interactions. An Evolutionary Approach, pp. 132-154. , Herrera C.M., and Pellmyr O. (Eds), Blackwell Science, OxfordJanzen, D.H., Seed-eaters versus seed size, number, toxicity and dispersal (1969) Evolution, 23, pp. 1-27Janzen, D.H., Seed predation by animals (1971) Annu. Rev. Ecol. Syst., 2, pp. 465-492Janzen, D.H., Escape in space by Sterculia apetala seeds from the bug Dysdercus fasciatus in a Costa Rican deciduous forest (1972) Ecology, 53, pp. 350-361Janzen, D.H., Ficus ovalis seed predation by an Orange-chinned parakeet (Brotogeris jugularis) in Costa Rica (1981) Auk, 98, pp. 841-844Leimu, R., Syrjänen, K., Ehrlén, J., Lehtilä, K., Pre-dispersal seed predation in Primula veris: among-population variation in damage intensity and selection on flower number (2002) Oecologia, 133, pp. 510-516Lorenzi, H., (1998) Árvores brasileiras: manual de identificação e cultivo de plantas arbóreas nativas do Brasil, 1. , Editora Plantarum, Nova Odessa, BrazilManly, B.F.J., (1997) Randomization, Bootstrap and Monte Carlo Methods in Biology. second ed., , Chapman & Hall, LondonMartuscelli, P., Ecology and conservation of the Red-tailed Amazon Amazona brasiliensis in south-eastern Brazil (1995) Bird Conserv. Int., 5, pp. 225-240Mattson, W.J., Cone resources and the ecology of the red pine cone beetle, Conophthorus resinosae (Coleoptera: Scolytidae) (1980) Ann. Entomol. Soc. Am., 73, pp. 390-396Molau, U., Eriksen, B., Knudsen, J.T., (1989) Predispersal seed predation in Bartsia alpina. Oecologia, 81, pp. 181-185Munn, C.A., Thomsen, J.A., Yamashita, C., The Hyacinth macaw (1990) Audubon Wildlife Report, pp. 404-419. , Chadler W.J. (Ed), Academic Press, New YorkMyers, N., Mittermeier, R.A., Mittermeier, C.G., Fonseca, G.A.B., Kent, J., Biodiversity hotspots for conservation priorities (2000) Nature, 403, pp. 853-858Notman, E., Gorchov, D.L., Cornejo, F., Effects of distance, aggregation, and habitat on levels of seed predation for two mammal-dispersed neotropical rain forest tree species (1996) Oecologia, 106, pp. 221-227Ollerton, J., Lack, A., Relationships between flowering phenology, plant size and reproductive success in Lotus corniculatus (Fabaceae) (1998) Plant Ecol., 139, pp. 35-47Paranhos, S.J., 1995. Biologia comportamental de Brotogeris versicolurus chiriri (Vieillot, 1817) (Aves: Psittacidae): alimentação e reprodução. Masters thesis. Universidade Estadual Paulista, BrazilParchman, T.L., Benkman, C.W., Diversifying coevolution between crossbills and black spruce on Newfoundland (2002) Evolution, 56, pp. 1663-1672Pizo, M.A., Simão, I., Galetti, M., Diet and flock size of sympatric parrots in the Atlantic forest of Brazil (1995) Ornitol. Neotrop., 6, pp. 87-95Root, R.B., Organization of plant-arthropod association in simple and diverse habitats: the fauna of collard (Brassica oleracea) (1973) Ecol. Monogr., 43, pp. 95-120Roth, P., Repartição do habitat entre psitacídeos simpátricos no sul da Amazônia (1984) Acta Amazon, 14, pp. 175-221Schupp, E.W., Factors affecting post-dispersal seed survival in a tropical forest (1988) Oecologia, 76, pp. 525-530Sheppard, A.W., Cullen, J.M., Aeschlimann, J.P., Predispersal seed predation on Cardus nutans (Asteraceae) in southern Europe (1994) Acta Oecol, 15, pp. 529-541Sick, H., (1997) Ornitologia Brasileira, , Editora Nova Fronteira, Rio de JaneiroSiepielski, A.M., Benkman, C.W., Interactions among moths, crossbills, squirrels and lodgepole pine in a geographic selection mosaic (2004) Evolution, 58, pp. 95-101Sperens, U., Fruit production in Sorbus aucuparia L. (Rosaceae) and pre-dispersal seed predation by the apple fruit moth (Argyresthia conjugella Zell.) (1997) Oecologia, 110, pp. 368-373Trivedi, M.R., Cornejo, F.H., Watkinson, A.R., Seed predation on Brazil Nuts (Bertholletia excelsa) by Macaws (Psittacidae) in Madre de Dios, Peru (2004) Biotropica, 36, pp. 118-122Turner, C.E., Piper, G.L., Coombs, E.M., Chaetorellia australis (Diptera: Tephritidae) for biological control of yellow starthistle Centaurea solstitialis (Compositae) in the western USA: establishment and seed destruction (1996) Bull. Entomol. Res., 86, pp. 177-182Yamashita, C., Valle, M.P., On the linkage between Andorhynchus macaws and palm nuts, and the extinction of the glaucous macaw (1993) Bull. Br. Onithol. Club., 113, pp. 53-61