Structure and Diversity of Vocalisation of an Endemic Forest Bird (Brown-Capped Babbler Pellorneum fuscocapillus) Across the Climatic Gradient in Sri Lanka

A climate-driven divergence in vocalization patterns has been identified in the Brown-Capped Babbler (Pellorneum fuscocapillus), an endemic forest bird of Sri Lanka. This study, conducted across four distinct climatic zones—including Sinharaja Forest Reserve and Mihintale Sanctuary—revealed that vocal repertoires vary significantly between wet and dry zones, as well as between mid and low elevations. Principal Component Analysis (PCA) demonstrated clear clustering of vocalizations based on climate, suggesting potential evolutionary adaptations to environmental conditions. The research analyzed seven vocal types, with 'Pretty dear' and 'Long chirp' being the most prevalent, using parameters like frequency modulation and temporal structure. This finding highlights the species' complex communication system as a possible indicator of ecological and evolutionary responses to climatic gradients.

Panduwawala, P. P., Wickramasinghe, S., & Senevirathne, S. S. (2017). Structure and Diversity of Vocalisation of an Endemic Forest Bird (Brown-Capped Babbler Pellorneum fuscocapillus) Across the Climatic Gradient in Sri Lanka. Proceedings of International Forestry and Environment Symposium, 22(0). https://doi.org/10.31357/fesympo.v22i0.3275