The dynamics of the abundance, age, and sex structure of the Solovetsky reproductive gathering of the Beluga whale Delphinapterus leucas (Onega Bay, White Sea)

Autor: O. I. Kirillova, A. D. Chernetsky, V. M. Bel’kovich, V. V. Krasnova
Rok vydání: 2012
Předmět:
Zdroj: Russian Journal of Marine Biology. 38:218-225
ISSN: 1608-3377
1063-0740
DOI: 10.1134/s1063074012030078
Popis: Based on the data from long-term research in 1999–2009 we studied the population dynamics of Beluga whales in the Solovetsky reproductive gathering (RG) in the White Sea. This aggregation of Beluga whales is formed each year in the second half of May after the break-up of fast ice and persists to September inclusive. The aggregation numbers about 100 individuals from visual observations, with long-term variations of 20–30 individuals. The percentage of whales of different age groups also varied in the gathering depending on year, but typically one half was formed by mature animals and the other half consisted of immature whales and yearlings. There are two pronounced peaks in numbers for the summer season in the Solovetsky Beluga RG. The number of Belugas increased with the appearance of males and females that were ready to breed and females that were ready to bear calves. The daily dynamics of Belugas in the gathering largely depended on the time of day and tidal regime. In the summer season, the state of the sea and human impacts were key factors in number fluctuations of the Belugas of the Solovetsky RG. The revealed negative correlation of the long-term population of Belugas in the gathering on air temperature is considered as a special instance of general laws of the migration activities of Beluga whales in the White Sea.
Databáze: OpenAIRE
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