Timeline: 2022- ongoing
People: Pooja Pawar, DevAnand N, Rohit Naniwadekar
Collaborators: Janhavi Joshi, Bharti Dharapuram, Uma Ramakrishnan, Devkant Singha
Funding: Science & Engineering Research Board, CSIR-Center for Cellular and Molecular Biology, Hyderabad, Rainmatter Foundation Fellowship, Wildlife Conservation Trust, M. M. Muthiah Research Foundation

What We Do?

Hornbills represent an ecologically keystone group of forest-dwelling birds in India. These long-lived, wide-ranging, and predominantly frugivorous species play a vital role in maintaining forest dynamics through large-scale seed dispersal, thereby sustaining tropical ecosystem structure and regeneration. Naturally occurring at low population densities, hornbill populations have been further reduced by habitat loss, deforestation, and hunting, making their long-term persistence increasingly uncertain.

From an evolutionary and conservation genomics perspective, parameters such as genetic diversity, effective population size, gene flow, and population connectivity are fundamental determinants of a species’ adaptive potential and survival. Genetic diversity forms the basis of evolutionary resilience, allowing populations to respond to environmental and climatic fluctuations. Preserving intra-specific genetic variation and evolutionarily distinct populations enhances long-term adaptability and minimizes extinction risk. In the context of rapid habitat fragmentation and accelerating climate change, understanding the genomic consequences of anthropogenic pressures is critical. Population isolation and demographic bottlenecks can erode genetic variability, reduce effective population size, and diminish adaptive capacity.

Why This Matters?

This project integrates comparative phylogeography, population genomics, and landscape genetic analyses to investigate evolutionary history, population structure, and genetic connectivity among threatened hornbill species across India. Using high-resolution genomic data, we aim to quantify spatial patterns of genetic variation, and role of various drivers on these iconic seed dispersers.

Key Findings 

• We have assembled the hybrid reference genomes for four hornbill species which would serve as a critical resource for future genomic studies.

• The population trajectories of these four species indicate dramatic decline in their effective population sizes during the Pleistocene epoch that was marked with climatic fluctuations. 

• The genetic study on point endemic Narcondam Hornbill indicates lower genetic diversity as compared to its congenus Wreathed Hornbill. The lower genetic diversity can be attributed to the founder effect (small founder population), past perturbations that lead to population decline.  

Publications

1. Pawar, P. Y*., Krishnan, G., Naniwadekar, R., & Joshi, J. (2025). De novo genome assemblies  of threatened Asian hornbills (Bucerotidae) reveal declining population trajectories during the  late Pleistocene. bioRxiv, 2025-05.

2. Devanand, N., Bharti, D.K., Pawar, P.Y., Gopal, A., Ghuman, S., Page, N., Joshi, J. & Naniwadekar, R., (2025). Comparing the genetic diversity of two threatened Rhyticeros hornbill species with contrasting geographic range sizes.  bioRxiv, 2025-10