Padrões de interações mutualísticas entre espécies arbóreas e aves frugívoras em uma comunidade de Restinga no Parque Estadual de Itapuã, RS, Brasil

Abstract

RESUMO -(Padrões de interações mutualísticas entre espécies arbóreas e aves frugívoras em uma comunidade de Restinga no Parque Estadual de Itapuã, RS, Brasil). Padrões de interação entre aves frugívoras e espécies arbóreas, com suas variações sazonais, foram determinados em uma mata de Restinga. Foram feitas observações visuais e capturas da avifauna, ao longo de um ano, estimando-se a conectância do sistema mutualístico e o índice de importância das espécies. Também foi elaborada a rede de interações do sistema e feita a análise da variação das interações entre as estações do ano. Foram registradas 18 espécies animais e 11 vegetais interagindo, com uma conectância de 25,3%. Turdus amaurochalinus e T. rufiventris apresentaram maior número de visitas, interagiram com a maioria das espécies arbóreas e tiveram o maior índice de importância, sendo caracterizadas como as principais dispersoras em potencial. Ocotea pulchella e Myrsine spp. foram registradas com os maiores números de eventos de consumo de frutos pelas aves. No entanto, Ficus organesis interagiu com mais espécies dispersoras, além de ter a maior importância na dieta das aves. Observaram-se variações na quantidade de eventos de frugivoria ao longo do ano, com um aumento significativo na primavera. Além disso, verificou-se um aumento nas espécies frugívoras durante a primavera e verão, bem como no número de espécies arbóreas visitadas nessas estações. Palavras-chave: interação ave-planta, frugivoria, estrato arbóreo, Mata AtlânticaABSTRACT -(Patterns of mutualistic interactions between tree species and frugivorous birds in a restinga community at Itapuã State Park, Rio Grande do Sul, Brazil). Interaction patterns between frugivorous birds and tree species, with seasonal variations, were determined in a restinga forest. Visual observations and bird captures were performed throughout a year, estimating the connectance of the mutualistic system and the importance index of species. The interaction network of the system was also worked out and seasonal variation in these interactions was analyzed. Eighteen animal species and 11 tree species were recorded as interacting, with a connectance of 25.3%. Turdus amaurochalinus and T. rufiventris had the highest number of visits, interacted with most tree species and had the highest importance index, being characterized as the main potential dispersers. Ocotea pulchella and Myrsine spp. were recorded with the highest numbers of fruit consumption events by the birds. Ficus organensis, however, interacted with more disperser species, besides being most important for the birds' diet. Variations in the number of frugivory events throughout the year were observed, with a significant increase in spring. Moreover, an increase in frugivorous species was verified during spring and summer, as well as in the number of tree species visited during these seasons.

Medium and large sized mammals of a semideciduous forest remnant in southern Brazil

“…The metropolitan region of Porto Alegre is made up of a vegetational mosaic composed of fields and forests, predominant especially in the hills, which results from the combination of geomorphological diversity and transitional climatic conditions, because it is situated between temperate and tropical regions (Menegat et al 1998). Such conditions, although having revealed a high richness and diversity of species for other faunistic groups (Lema et al 1983, Scherer et al 2006, Santos & Cademartori 2010, have been little explored with respect to the mammalian fauna. The species richness of mammals has been insufficiently studied in the forest remnants of the region (Antonio 1996, Sestren-Bastos 2006, Penter et al 2008, where there is a need for information from more long-term inventories.…”

Birds foraging for fruits and insects in shrubby restinga vegetation, southeastern Brazil

“…However, there is little ecological information on restinga birds to confirm whether they have similar habits to other tropical ecosystems, including other vegetation types within the Atlantic forest region (but see Novaes 1950, Venturini et al 1996, Castiglioni 1998, Argel-de-Oliveira 1999, Scherer et al 2007). The seasonal presence of non-breeding birds , Alves et al 2004) and the great threat to restinga from farmers and construction of second homes along the beach (Lacerda et al 1993) highlight the importance of ecological studies that may inform conservation measures.…”

Foraging behavior and diet of the vulnerable Cinereous Warbling-finch Poospiza cinerea (Aves, Emberizidae)

“…Other brazilian Poospiza species (P. cabanisi, P. melanoleuca, P. nigrorufa and P. torquata) are granivorous, omnivorous, granivourousfrugivorous or granivorous-insectivorous (Chatellenaz, 2004;Giraudo et al, 2006;Malizia et al, 2005;Scherer et al, 2005Scherer et al, , 2007Silva, 2006). Poospiza thoracica has a diet similar to that of P. cinerea, because it feeds mainly on arthropods (64%, n=170), but fruits (23%, n=170) and flowers (13%, n=170) represent a considerable amount of its diet (Parrini et al, 2009).…”