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

Abstract

Indian Skimmer Rynchops albicollis Swainson, 1838 is a riverine habitat specialist bird and a species of significant conservation concern. In 2020 it was up-listed to the ‘Endangered’ category of the IUCN Red List. Breeding grounds of the species are known from the major rivers of India like Ganga, Chambal, Son, and Mahanadi. We monitored breeding colonies of the species in two breeding seasons (2017 and 2018) in the middle Ganges stretch. We identified nine nesting islands and monitored a total of 111 active nests during the study period. A total of 302 eggs were counted with clutch sizes ranging 1–5 and the mean clutch size of 2.7 (±1.18 SD). We observed a 10% & 7% of hatching and fledgling success rate in 2017 and 10% & 17% in 2018, respectively. Low breeding success was probably due to the severe anthropogenic factors such as egg collection, cattle trampling, and stochastic weather events such as flooding and sand inundation by sand storms in nests. We also recorded instances of nest abandoning because of unknown reasons. This article recommends more surveys to identify new breeding colonies of Indian Skimmer in the middle Ganges and subsequently provide adequate protection to the colonies. We also recommend sensitization programs for different stakeholders to create more awareness for the conservation of this threatened species in the middle Ganges stretch.