Native shade trees aid bird conservation in tea plantations in southern India

Abstract

In the Western Ghats, India, we study how different intensities of tea cultivation influence birds. We compared bird communities in conventional monoculture tea and mixed-shade tea plantations, both of which use agrochemicals, with organic tea plantations, a rainforest fragment, and continuous rainforest within the Anamalai Tiger Reserve. In 225 point count surveys, overall bird species richness and abundance were lowest in conventional tea and up to 33% higher in organic tea. Mixed-shade tea had 40% higher species richness (including 15 canopy and 4 shrub and mid-storey species - primarily frugivores, nectarivores and insectivores), and 83% higher bird abundance than conventional tea, with a greater proportion of forest-affiliated birds and similarity in species composition with forest sites. The rainforest fragment and continuous rainforest had a higher proportion, richness and abundance of forest-affiliated birds and fewer open-country birds, unlike tea plantations where the pattern was reversed. Habitat associations of 62 bird species in indicator species analysis revealed similar patterns. Thus organic tea is better than conventional tea for birds, but mixed-shade tea is even better, although still poorer than forests. Retaining or promoting native shade trees in tea plantations will increase bird diversity and abundance, including of forest-affiliated species and support landscape-level bird conservation.