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

Abstract

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.

What is on the menu for frugivorous birds in the Cerrado? Fruiting phenology and nutritional traits highlight the importance of habitat complementarity

“…This supports previous studies showing that vegetation characteristics that delimit the different grassland, savanna and forest habitats of the Cerrado do not prevent birds from tracking resources in space (Tubelis et al 2004;Piratelli & Blake 2006;Maruyama et al 2013). In this sense, although there are differences in the composition of fruit eating birds in forest and savanna habitats (Purificação et al 2014), around 60 % of frugivorous animals in the Cerrado occur in more than one type of habitat (Kuhlmann & Ribeiro 2016a). Other studies have also indicated how interactions between plants and frugivorous birds connect and are maintained across distinct habitats (e.g.…”

“…Fruits of Melastomataceae plants also contained many tiny seeds. Numerous tiny seeds associated with sugar-rich pulp were also observed in C. pachystachya, whose fruits are consumed both by bats (Sato et al 2008) and birds (Silva & Pedroni 2014;Purificação et al 2014), indicating generalist seed dispersal interactions. None of these plants had significant lipid content, which is a characteristic often associated with fruits consumed by more specialized frugivores (Stiles 1993;Jordano 2014).…”

“…Other studies have also indicated how interactions between plants and frugivorous birds connect and are maintained across distinct habitats (e.g. Maruyama et al 2013;Purificação et al 2014). Hence, distinct Cerrado vegetation types are interdependent, which is a key feature that should be considered in conservation and restoration policies for this ecosystem.…”

“…Such connections among habitats have important consequences for conservation of the Cerrado (Tubelis et al 2004;Kuhlmann & Ribeiro 2016a), also in the context of plants and frugivorous birds interactions (e.g. Maruyama et al 2013;Purificação et al 2014). Moreover, identifying plants that provide fruits during periods of scarcity could help identify potential "keystone resources" (Peres 2000;Bleher et al 2003;Maruyama et al 2013), which should be considered in conservation and restoration planning.…”

Bird-plant interactions on the edge of a forest fragment in southwestern Brazilian Amazonia

“…The Neotropical region has the greatest known diversity of specialized frugivore birds, although studies focusing on the relationships between Neotropical plants and their dispersers are still incipient (Dugger et al, 2019). This situation is most evident in the Amazon region where the mutualistic relationships between frugivorous birds and plants are relatively poorly studied, considering the vast size of this biome (Parrini, Raposo, Del Hoyo, & Silva, 2013;Purificação, Pascotto, Pedroni, Pereira, & Lima, 2014;Dugger et al, 2019). Given these shortcomings, the present study investigated bird-plant interactions in an area of forest edge habitat in the southwestern Brazilian Amazon region, based on the analysis of the seeds found in fecal samples obtained from local birds captured in mist nets.…”