Distribution and Status of the Pallas's Gull Ichthyaetus ichthyaetus (Pallas, 1773) in the Reservoirs of the Palearctic: Review

Abstract

The Pallas's Gull Ichthyaetus ichthyaetus is a piscivorous gull, some local populations of which are rare and vulnerable. The review presents data on the status and distribution of the Pallas's Gull in the reservoirs of the Palearctic—water bodies in which the water level is controlled by humans. The aim of the study was to assess the current state of the species in the reservoirs of the Palearctic. The review was based on 1080 publications found in the search engines Yandex, Google, Google Scholar, eLybrary. During the last 35 years, the Pallas's Gull has been found in 63 reservoirs of the Palearctic. Breeding has been established in 11 reservoirs, breeding has not been established in 43 reservoirs, and birds were present in 9 reservoirs, but the status was not specified. Two-thirds of the reservoirs where the gull was recorded or bred were located in the European part and only 1/3 in Asia. It is assumed that up to 5000 adults (0.45%-4.0% of the global population of the species) breed annually in the reservoirs of the Palearctic, and the reservoirs are not the main habitats for maintaining and reproducing the population of the species. The majority of the breeding population reproduces in natural water bodies, and the reservoirs of the Palearctic are important for the maintenance of non-breeding individuals. Detection of presumed breeding and new breeding colonies in reservoirs north of the historical range of the species has been established on the Russian Plain, in the Urals and Trans-Urals. The reservoirs of Russia play a leading role in providing breeding sites for the species in water bodies of this type. An analysis of the data allows us to state the important and increased role of reservoirs in the modern distribution and expansion of the range of the Pallas's Gull in the Palearctic