Frugivoria e dispersão de sementes de Talauma ovata (Magnoliaceae) no sudeste brasileiro

Some plants are widely distributed, ranging in different vegetation types. Since bird distribution can be directly associated to vegetational cover, we expect that seed dispersers can also vary following phytophysiognomy for some ornithochorous plants. The purpose of this paper was to describe potential seed disperser birds of Talauma ovata (Magnoliaceae) in semideciduous Atlantic forest and cerrado fragments in south-east Brazil. In 79 h of focal observations we recorded 1085 visits of 25 different bird species consuming T. ovata diaspores. Although most bird species observed consuming T. ovata diaspores present generalist habits, they were potential seed dispersers, presenting high visits rate and do not staying a long time on the plants, favoring seed dispersal efficiency. Fruit consumption was not different between species in the study sites and the time spending on the plants was not different between species in semideciduous forest, but was different in cerrado. Agonistic encounters were observed mainly in the end of fruiting season, but was not relevant to decrease the number of seeds dispersed by birds. The occurrence of different potential seed dispersers between areas, such as Cyanocorax cristatellus (Corvidae), Schistochlamys ruficapillus (Emberizidae) and Mimus saturninus (Mimidae), which are endemic from the cerrado ecosystem and could rarely be found in semideciduous forest, suggests that seed dispersers can vary according to phytophysiognomy characteristics. Our results also indicate that the evolution of a generalist seed dispersal system such as observed for T. ovata can make possible the colonization of different ambients. Furthermore, the high number of visits recorded for both areas suggests that the fleshy arils of T. ovata are important feeding resources for birds.

Componentes quantitativos e qualitativos da dispersão de sementes de Struthanthus flexicaulis (Loranthaceae) em uma área de campo rupestre do sudeste brasileiro

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Cranial osteology in mornoticlae (Aves : Coradiformes)

Momotidae (motmots) is found throughout Latin America between Mexico and northern Argentina. Given the absence of detailed studies of cranial osteology of Momotidae in the literature, this article presents a comprehensive description of the variation of the cranial osteology in all nine species of Momotidae and compares the results with published studies of other families of Coraciiformes and families in other orders. In addition, the cranial structures described are related to ecological and behavioral aspects of Momotidae. The cranial osteology of Baryphthengus ruficapillus is described in detail and compared with other species of Momotidae. The results indicate the presence in Momotidae of modified cranial structures, among which the most conspicuous are the frontal, lacrimal, squamosal, orbital, and laterosphenoid regions, as well as the palatine, upper jaw, pterygoid, and mandible. (C) 2003 Wiley-Liss, Inc.

Limitações bióticas afetando o recrutamento da palmeira Euterpe edulis em uma ilha continental da Mata Atlântica

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)