Redes de interações de frugivoria por aves em plantas nativas e exóticas em ambiente urbano

Abstract

Fruit consumption by birds is well reported in Brazil, but few studies compared the use of native and exotic fruit, especially in urban environment. Network Theory may be a useful tool in such studies, since it allows to evaluate multiple species of both animal and plants involved in interactions. The goals of this thesis were to evaluate bird-plant interaction networks in urban environment on regional and local scale; to assess the role of native and exotic plant species in the networks and to compare the consumers assembly interacting with native and exotic plants. We reviewed published literature on bird frugivory in urban areas of Brazil and made a meta-analysis to generate an interaction network on a regional scale. We also made observations in urban green areas of Uberlândia, Minas Gerais State in four native plant species (Matayba guianensis, Xylopia aromatica, Cecropia pachystachya e Phoradendron affine) and four exotic species (Michelia champaca, Muntingia calabura, Roystonea borinquena e Ligustrum lucidum). 320 hours of observations were carried out between May 2012 and April 2014 during morning and late afternoon. We included 15 papers in our metaanalysis in which 70 bird species consumed fruits from 15 plant species (six exotic e nine native). The bird species recorded in the greater number of papers was Tangara sayaca (n=14) and the most representative family was Tyrannidae (n=18 spp.). Bird fauna consuming native and exotic fruits were not in different groups and the interaction network on a regional scale was significantly nested (NODF=0,30; p < 0,01) but not modular (M= 0,36; p= 0,16). Two exotic plant species are part of the generalist core (region with higher interaction density) of the frugivory network in urban environment in Brazil (Ficus Microcarpa e M. champaca). At Uberlândia we recorded 540 visits with fruit consumption, performed by 31 bird species from four orders and 12 families.The most representative family was Tyrannidae (n=9 spp.) and Pitangus sulphuratus was the bird species interacting with higher plant diversity (n= 7 spp., 4 exotic e 3 native). Plant species with higher number of interactions were Xylopia aromatica (native) and Michelia champaca (exotic), both consumed by 13 bird species. A total of 339 visits were recorded on exotic plant species and 201 on native plants and 2055 fruits were consumed, 1450 native and 655 exotic fruits. Comparing native and exotic plant species there was significant difference in the number of visits (U=1018,5; p<0,05), but not in the number of fruits consumed (U=1301,50; p=0,7). Interaction network on a local scale was not significantly nested (NODF=40,11; p=0,20) nor modular (M=0,34; p=0,35). There are both native and exotic plant species on central positions of the local network and only two species comprise the generalist core, X. aromatica (native) e M. champaca (exotic). Bird assembly consuming native and exotic fruits did not form different groups. Results suggest that a relatively diverse set of birds consume fruits in urban environmen...