EXTENDED MOLTING AGAINST THE BACKGROUND OF CLIMATE WARMING IS THE MAIN REASON FOR THE EMERGENCE OF THE BAIKAL SEAL (<i>PUSA SIBIRICA</i>, PINNIPEDIA) TO COASTAL ROOKERIES

Abstract

An analysis of the video films taken at a Baikal seal rookery in 2011–2021 on the Long Island, Ushkany Islands, northern Lake Baikal, showed that the total number and time of the emergence of animals on the shore were determined by the time of the disappearance of ice in the northern part of the lake. Yet, regardless of the ice regime, a significant part of the animals (up to 80%) leaving land continued molting. At the same time, the nature of molting (its topology) was disturbed in the vast majority of cases, molting being diffuse in character, often with elements of pathological manifestations. The number of molting individuals (in %) decreased by autumn, but still remained large, even though such dynamics were observed not every year. Incomplete molting did not interfere with animals’ fattening, as most seals were well or very well fed (especially by autumn), with individuals leaving the rookery immediately after the disappearance of ice also being well fat. At the same time, animals in coastal haulouts showed pathologies of the skin and hairline annually, the occurrence of which was probably associated, among other things, with abnormal molting. A large number of animals seem to leave for wintering with an incomplete molt, with their further fate being unknown. The data obtained indicate that disturbing the dormancy of molting seals on rookeries is inadmissible, since the excessive factor of disturbance (observed at the rookery at the present time) can play significant negative roles through affecting the physical condition (health) of animals.