Bird communities in Panamanian black mangroves: potential effects of physical and biotic factors

Abstract

Isolated in forest patches, mangrove stands often experience different physical conditions (rainfall, tide, salinity) despite similar floristic composition and structure. These abiotic factors are known to influence mangrove phenology but their potential effect on the local invertebrate and bird fauna have not been investigated. This study contrasts two sites of black mangrove (Avicennia germinans) located on the Caribbean and Pacific coasts of Panama. The two mangrove sites are characterized by different rainfall and tide patterns, and consequently ground inundation and salinity. These mangrove sites also differed in their plant phenology as well as invertebrate and bird composition. Although 95% of the bird species sampled occur on both coasts, the two mangrove sites shared only 34%. Moreover, each bird community was composed of a particular feeding guild assemblage consistent with the abundance distribution of their invertebrate-prey. Because floristically similar mangrove stands can support different invertebrate and bird faunas, conservation efforts should target mangrove patches submitted to different physical factors in order to preserve biodiversity.