Bengal Launches First-Ever State-Wide Owl Survey to Map 23 Species
West Bengal is embarking on a groundbreaking initiative to map the distribution and abundance of owls across the state. This marks the first time such a comprehensive survey is being conducted in India. The state is home to 23 species of owls, and the project aims to provide detailed data on their status.
Survey Details and Timeline
The owl survey will run from January to May, taking advantage of the peak activity period for these nocturnal birds. It will cover both protected and non-protected areas, including forests, wetlands, grasslands, and urban environments. This wide-ranging approach ensures a thorough assessment of owl habitats throughout Bengal.
The Birdwatchers' Society is leading the effort in collaboration with WWF-India and the state forest department. The work falls under WWF-India's Raptor Conservation Programme.
Objectives and Conservation Goals
Sujan Chatterjee, founder and secretary of the Birdwatchers' Society, outlined the primary goals. He said the survey will establish a baseline for owl species across different habitats. It will also identify key nesting, roosting, and foraging sites while assessing threats to plan effective conservation efforts.
Ratul Saha, director of the Raptor Conservation Programme at WWF-India, emphasized the importance of owls. He noted that owls have coexisted with humans for centuries, often heard more than seen. They play a crucial role in balancing ecosystems by controlling pests and indicating environmental health. However, knowledge about their current distribution remains limited.
Through this survey, WWF-India hopes to document these nocturnal neighbors. The approach combines scientific methods with local knowledge from forest departments and birders who understand the landscapes intimately.
Methodology and Systematic Coverage
To ensure systematic coverage, Bengal has been divided into survey zones using a robust grid-based framework. Each zone is further subdivided into 20 by 20 kilometer grids. A total of 267 grids were created, with 100 representative grids selected for the survey.
Historical eBird records from the past five years were overlaid on the grid framework. This helped visualize grids with verified owl species presence.
Kanad Baidya, founder of the Birdwatchers' Society, explained the survey process. Twelve focal point counts will be conducted per grid, spaced at least three kilometers apart. At each point, observers will record owls visually or acoustically for ten to fifteen minutes. Owl vocalizations will be captured using call playback techniques.
All surveys will occur during peak owl activity hours, specifically four hours after sunset.
Data Collection and Targeted Species
The survey will document various observations to build a comprehensive dataset. Key data points include all species with number of sightings, owl behavior, age, sex, plumage, habitat details, and threats or disturbances near sightings. GPS locations, weather conditions, and visibility will also be recorded.
Chatterjee highlighted some targeted species for the survey. These include the brown fish owl, oriental bay owl, and Eurasian scops owl. The findings will support future conservation initiatives and long-term studies, ensuring that planning is grounded in both science and local experience.
