Why the population of the northern fur seals (Callorhinus ursinus) of Tyuleniy Island does not recover following the harvest ban: Analysis of 56 years of observation data

• Main Authors: Zhdanova, Oksana L., Kuzin, Аlexey Е., Skaletskaya, Elena I., Frisman, Еfim Ya.
• Format: Article in Journal/Newspaper
• Language: unknown
• Subjects: Callorhinus ursinus; Northern fur seal
• Online Access: http://www.sciencedirect.com/science/article/pii/S0304380017303873

Following many years of managed harvest, the population size of Northern fur seal on Tyuleniy Island appeared to be depressed. In order to preserve the population, the harvest was first significantly limited, and then banned altogether. However, the birth rates have never recovered. We perform the estimation and analysis of survival rates of different groups of males in the population with the goal of elucidating the underlying changes in intra-population dynamics. We use the estimated numbers of adult males and pups in the rookery along with the exact numbers and ages of animals, harvested over the years. Callorhinus ursinus; Mathematical modeling; Harvest; Conservation; Survival rates estimation;