Spatial niche variation in two sympatric species of Bokermannohyla (Anura: Hylidae) in southeastern Brazil

Abstract

We studied patterns of microhabitat use by adults of two sympatric Bokermannohyla species at the Reserva Particular do Patrimônio Natural Santuário do Caraça, southeastern Brazil. We selected three streams, one where both species occurred in syntopy and the other two where each one occurred alone. We sampled 150-m transects in each stream throughout 1 year, recording microhabitat features for each frog located (substrate type, height and distance from water). Microhabitat availability varied between dry and wet seasons in all streams, and overall microhabitat diversity changed in two streams. Bokermannohyla nanuzae seemed to have a niche contraction in the presence of Bokermannohyla martinsi, but this only happened during the dry season. Microhabitat requirements during the wet season may be closely linked to similar reproductive needs that probably represent a strong selective pressure, forcing niche overlap.

Keywords:

• Bokermannohyla nanuzae
• Bokermannohyla martinsi
• syntopy
• microhabitat use
• niche overlap

Acknowledgments

We are grateful to R.C.C. Souza, A.S.B. Gontijo, M.R.J. Corrêa, G.C. Conrado, V. Borges, R.C. Pires and M.G. Brandão for help during field work, to the staff of the RPPN Santuário do Caraça for permits and logistics, the Instituto Brasileiro do Meio Ambiente e dos Recursos Naturais Renováveis for a permit (23773–1), and the Fundação de Amparo à Pesquisa do Estado de Minas Gerais (Fapemig) for financial support. A scholarship was awarded to N.S.G. Lima by the Coordenação de Aperfeiçoamento de Pessoal de Nivel Superior (CAPES) and A Research Productivity grant (301077/2010-0) was given to P.C. Eterovick by the Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq).