Breeding ecology and causes of nest failure in the Indian Skimmer Rynchops albicollis

New species for the avifauna of adjoining coastal areas of Purba Medinipur district, West Bengal, India

“…Currently, its breeding range is restricted to India and western Bangladesh (Kabir et al 2016). In India, it is known to breed in National Chambal Sanctuary, Narora Ramsar site, River Mahanadi, Son Gharial Sanctuary, River Ganga, Turtle Wildlife Sanctuary and Pong Dam (Ankit et al 2018, Debata et al 2019, Mital et al 2019. A single individual was continuously observed by PD, between 13 April and 16 April 2021 at sea beach of Nijkasba, during low tide between 12:00 pm and 5:30 pm.…”

Observations on Indian Skimmer Rynchops albicollis Swainson, 1838 (Aves: Charadriiformes: Laridae) breeding colonies in Middle Ganges stretch, India

“…Historically, the population was distributed in the major river systems of Myanmar, Cambodia, Vietnam, and the Mekong delta (Sundar 2004). However, the current distribution of the species is believed to be from Pakistan and Nepal, with the stronghold of the population in India and Bangladesh (Rajguru 2017;Debata et al 2019). In India, the breeding population of the species is known from the major rivers like Chambal, Mahanadi, Ganges, and Son (BirdLife International 2023).…”

“…The breeding season starts after the winters ranging from February to May in different breeding sites. Indian Skimmers breed in colonies and sometimes with other species like River Tern Sterna aurantia, Little Tern Sternula albifrons, River Lapwing Vanellus duvaucelii, and Small Pratincoles Glareola lactea (Rahmani 2012;Rajguru 2017;Ankit et al 2018;Debata et al 2019). Generally, Indian Skimmers lay eggs in sandy spits of emerged river islands; the clutch size ranges between 1-5, and both the sexes are involved in incubation and parental care after the hatching of eggs (Shaikh et al 2018;Debata et al 2019).…”

“…Also, there are records of stochastic weather events causing nest failure of the species at different breeding sites (Shaikh et al 2018;Debata 2019). However, the essential information pertaining to the breeding biology, threats to the breeding colonies, and long-term population monitoring are still very limited across its breeding ranges (Rajguru 2017;Debata et al 2019;Shaikh et al 2018). After the discovery of new breeding colonies in the middle Ganges stretch in the year 2017, we investigated different aspects of the breeding biology of Indian Skimmer.…”

“…Same survey and monitoring protocols were used in both the years of the breeding cycle. Successful nest was considered with the minimum one egg hatched in a particular nest and hatching success percentage was calculated as the proportion of number of successful nest and number of nests (Debata et al 2019). Whereas, the fledgling success was calculated as the proportion of nest with fledglings and number of successful nests.…”