Poles apart: the structure and composition of the bird community in bamboo in the Eastern Himalaya

Abstract

Bamboos (Poaceae: Bambuseae) are a unique and diverse group of plants (> 1500 species) that are found in tropical and subtropical regions of the world. Various birds, mammals, and insects use bamboo either directly or indirectly, and some species are obligate bamboo specialists. For instance, several species of Neotropical birds are found in bamboo alone. However, the mechanisms underlying dependence on/associations with bamboo are almost entirely unknown. We studied bird communities in bamboo and rainforest across two seasons in the Eastern Himalaya, where we explored a possible mechanism for bird associations with bamboo - dietary resource specialization. We calculated use of bamboo versus rainforest by bird species and described the structure and composition of the bird and arthropod communities in both habitats and seasons. We provide the first systematic evidence of bamboo specialist bird species from the Eastern Himalaya. Although the species richness of birds and arthropods in both habitats and seasons did not vary starkly, we found that the composition of bird and arthropod communities in both habitats and both seasons to be distinct. Interestingly, we found arthropod communities in different substrates of bamboo to also be distinct. Bird specialization in bamboo in the Eastern Himalaya could be because of their dietary specialization to the unique arthropods found in bamboo. The results from this study emphasise the importance of bamboo in the Eastern Himalaya and provide baseline information that might aid in conservation.