Interactions between frugivorous birds and plants in savanna and forest formations of the Cerrado

Interações entre aves frugívoras e plantas em formações savânicas e florestais do Cerrado

We recorded interactions between frugivorous birds and plants in the Cerrado and we assessed the role and importance of birds as potential seed dispersers. We analyzed the distribution of recorded feeding events, bird-plant interactions, and bird species composition between savanna and forest formations and between the dry and rainy seasons. Samplings were carried out from August 2009 to October 2010 and from November 2011 to August 2012 by means of line transects and focal observations. We recorded 348 feeding events and 187 interactions involving 44 plant species and 60 bird species. Most of the feeding events were observed in the forests and during the dry season (χ² = 39.529; gl = 1; p < 0.001). However, no significant difference was found in the number of interactions (χ² = 15.975; gl = 1; p = 0.06) between the two vegetation formations and between seasons. The bird species composition differed between savanna and forest formations (ANOSIM, R = 0.238; p < 0.001) and between the dry and rainy seasons (ANOSIM, R = 0.223; p < 0.001). Most of the potential seed dispersers were generalist birds that preferentially occupy forests during the dry season. Records of feeding events in forest formations increased in the dry season, indicating that birds use these sites as foraging areas during this period. We suggest that the preservation of forests in predominantly savanna-like ecosystems such as the Cerrado is extremely important for frugivorous birds and for frugivore-plant interactions.

Mutualistic interactions; Neotropical savanna; seasonality; seed dispersal