The Structure of the Reproductive Gathering of Beluga Whales, Delphinapterus leucas (Pallas, 1776), off Solovetsky Island (White Sea) as Inferred from Results of Photo Identification in 2007–2013

Resumo

The study of the summer gathering of beluga whales, Delphinapterus leucas, off Cape Beluzhy, Solovetsky Island, White Sea, whose results are considered in the present work, is based on the analysis of photo identification materials over a 7-year period (2007–2013). The Solovetsky gathering is a structural unit of the Onega subpopulation of White Sea beluga whales that consists of individuals with varying degrees of fidelity to this water area. The resident individuals of the Solovetsky gathering usually remain in these waters throughout the summer season, with some of them returning here after each winter, thus, exhibiting philopatry. The non-resident belugas (adult males and females) visit the area only for a certain period of time. During the summer they freely move within the Onega Bay. According to photo identification data, considering the rotation of individuals in the gathering, approximately 195.4 ± 23.5 animals can visit the study area during each summer. This value is significantly greater than the results of visual observations.