Fruit and flower availability affect bird assemblages across two successional stages in the Atlantic Forest

ABSTRACT

The Atlantic Forest is highly heterogeneous, with successional stages inducing shifts in food resources for birds. We investigated fruit and flower availability across two different successional stages in a continuous forest and the implications for bird communities. We sampled three sites in primary forest and three in second-growth forest. We established four plots (10 x 10 m) in each site and estimated the availability of zoochorous fruits and ornithophilous flowers and the occurrence of fruit-eating birds and hummingbirds. Unexpectedly, the availability of zoochorous fruits was similar for primary and second-growth stages, but the abundance of ornithophilous plants was higher in primary forest. Specialized frugivores were more abundant in primary forest, whereas abundance and richness of hummingbirds did not differ between the two successional stages. Frugivores responded to fruit availability in both successional stages, while hummingbirds varied according to ornithophilous plants only in the primary forest. Our results stress that the occurrence of bird species can vary according to resources availability in continuous areas, which contributes to high diversity in forests. These findings highlight the importance of preserving large continuous tracts of forests that promote a spatio-temporal distribution of resources, which maintains bird diversity and their interactions with plants.

KEYWORDS:

• Frugivorous birds
• fleshy fruits
• hummingbirds
• ornithophily
• neotropical
• feeding resources

Acknowledgments

We thank the support of the many collaborators who made this study possible. Instituto Florestal do Estado de São Paulo granted permission to work at Carlos Botelho, while SISBIO and IBAMA granted permissions to collect plant species (SISBIO #23627-1 and IBAMA #4968681). We personally thank Alexsander Zamorano Antunes, Alexander Christianini, Mercival Francisco, and Mauricio Cetra for their comments on earlier versions of this manuscript. We also thank Ana Carolina Devides Castello for help with drawing the map.

Disclosure Statement

No potential conflict of interest was reported by the authors.

Supplementary Material

Supplemental data for this article can be accessed here.

Additional information

Funding

This work was supported by the while SISBIO and IBAMA granted permission to collect plant species; [SISBIO #23627-1 and IBAMA #4968681].