Asian Waterbird Census records marginal increase in bird population but also habitat degradation

The annual Asian Waterbird Census (AWC) that was conducted in the wetlands of Thiruvananthapuram district recently recorded a marginal increase in overall waterbird population.

However, this masked a degradation in habitats, with several key sites showing a stark decline.

The survey, a joint initiative of WWF-India, the Trivandrum Birding Team, and the Social Forestry Division of Thiruvananthapuram under the Kerala Forest department, mobilised 50 volunteers across 11 sites, including a newly added location near Technopark.

The census yielded a total count of 4,868 birds from 73 species, of which 37 were migratory.

While the district-wide count showed a slim increase, a declining trend was observed at four of the 11 sites: Punchakkari wetlands, Akkulam Lake, Veli Lake and beach, and the Kannammoola canal. The Kadhinamkulam-Perumathura wetlands emerged the most populous site with 1,200 birds from 37 species, a significant jump from 306 birds last year. The Pazhanchira wetlands near Attingal were next with 1,183 birds from 38 species.

In contrast, the Punchakkari wetlands, a traditional birding hub, recorded a drastically low count of 358 birds from 34 species, as compared to last year’s 855 birds from 44 species.

Volunteers cited unscientific infrastructure development, intense photo tourism, and other anthropogenic pressures as primary causes for this decline.

Sites such as Akkulam Lake and the Kannammoola canal also reported low diversity and counts, with high levels of pollution from solid waste, liquid effluents, and invasive plant species severely impacting habitat quality.

Site-specific threats

The census report highlighted multiple, site-specific threats. The Punchakkari-Vellayani complex was suffering habitat loss owing to infrastructure and unregulated tourism. At the Aruvikkara reservoir, visibility and access for birds was hampered by a fence overrun with invasive creepers such as Mikania, alongside plastic pollution. Akkulam Lake showed a dominance of a single species, indicating low habitat diversity.

A widespread issue was the proliferation of invasive plant species such as water hyacinth and Siam weed across multiple wetlands.

The data point towards an urgent need for integrated wetland management strategies that address pollution, regulate unsustainable tourism, manage invasive species, and involve local communities in conservation efforts to safeguard critical waterbird habitats.

“The lower counts in specific sites are a direct indicator of habitat degradation and disruptive human interventions,” A.K. Sivakumar and Mohit M.G., coordinators of the census for the capital district, said. “However, the recorded presence of 37 migratory species across the district underscores the importance of these wetlands and calls for urgent, prioritised conservation measures for all sites.”