Namdapha Tiger Reserve in the north-east Indian state of Arunachal Pradesh is the only stronghold of the Critically Endangered white-bellied heron Ardea insignis, of which 8–10 individuals remain in India. The Reserve is the heron's only known breeding location in the country (Mondal & Maheswaran, 2014, BirdingASIA, 21, 13–17) and may be a place from where the birds disperse to nearby localities in search of new territories (Reddy et al., 2021, Indian Birds 17, 115–118).
From late 2024 onwards, there has been an increase in the number of local villagers collecting stink bugs Coridius nepalensis and Coridius singhalanus (Hemiptera: Dinidoridae), known locally as Gandhi puk, for consumption and sale. Local people have indicated they can sell the insects for USD 35–125 per kg, depending upon the variety. This potential income has motivated more people to collect the bugs, and this increased anthropogenic disturbance is causing white-bellied herons to desert their foraging grounds.
On a visit to Namdapha during 4–16 January 2025, as part of our research project on the white-bellied heron, supported by the Department of Science & Technology, Government of India, we traversed the majority of the Noa-Dihing and Namdapha Rivers within the Reserve, but saw no white-bellied herons. We have sighted herons along these river stretches on all previous trips in the last 20 years. We were surprised to find instead groups of 3–4 people per km turning boulders in search of stink bugs.
Our team members, who have been stationed inside the Reserve since September 2024, noticed intensive stink bug collection begin in the second week of November 2024 and continue to early February 2025. White-bellied herons tend to forage in open river stretches, and this increase in anthropogenic pressure will make it increasingly difficult for the species to find suitable sites within the Reserve. Furthermore, the heron's nesting season starts in June following courtship beginning during January–February in Namdapha. Absence of the heron in its known localities during this period therefore highlights concern for its reproduction in 2025. A pause in breeding may lead to a further decrease in the already limited population in India. If not addressed quickly, this emerging threat will lead to declines in the heron population in Namdapha Tiger Reserve, where the population is already decreasing (Menzies et al., 2025, Oryx, 58, 730–734). Stricter reserve management and provision of alternative incomes for inhabitants of the Reserve are required to mitigate the issue.
Open access
