The research of the northern sea lion population will take place on Medny Island. The species is included in the Red Data Book of the Russian Federation. Scientific group from Kamchatka Branch of Pacific Geographical Institute, Far Eastern Division of the Russian Academy of Sciences has already reached the island to count the numbers and birth rates of the animals. The specialists also continue behavior observation of the individuals tagged last year and have a closer view at motherhood of the sea lions.
The research will take place on Yugo-Vostochnoye rookery with its largest reproductive rookery of the sea lions in Kamchatka Region. In summer, 300 to 400 adult animals can be found here with 160 to 180 newborn pups. The specialists observe all of them.
“The bond between sea lion females and their pups frequently remains on the next year and the mother continues to breastfeed the pup. It is a peculiarity of the sea lions, which differentiate them from other eared seals and all the more so from the true seals, which are very rare to keep the bond for a long time. The link between sea lion mother and its pup can last for 2-3 years and up to 5 years! For several years, the female can abstain from breeding and feed the growing pup. Sometimes they can bear a new pup and feed both, but it is a very rare case. Usually if a female bears a new pup, she brakes the bond with the older pup”, said the head of the scientific group, MSU postgraduate in Biology, Natalia Laskina.
Photo by Andrey Shostak
How widespread such cases are? Which factors influence the bonds and does it influence the survival rate of the pups? These and other questions are still waiting to be answered.
Moreover, the group is planning to improve the methods of using the unmanned flying vehicles, such as quadrotors, along the high and rocky coastline of Medny Island. We started using this method recently.
“We will use the quadrotors with understanding of all the details of the rookery. We will adapt to it and we hope to create a structured working plan, which can be later used by other specialists”, said Natalia Laskina.
Photo by Natalia Laskina
The biologists will also register all other marine mammals spotted in the area: norther fur seals, sea otters, harbor seals, cetaceans and arctic foxes and other rare species, all of which will be included in the Nature Records of the Commander Islands Reserve.
It is worth mentioning that the expedition is organized in the framework of the international Population Monitoring and Ecology Research of the Sea Lion in the Far East of Russia project headed by Senior Research Associate of Kamchatka Branch of Pacific Geographical Institute, Far Eastern Division of the Russian Academy of Sciences Vladimir Burkanov. The project lasts for several decades and includes monitoring activity on all the sea lion rookeries on the Russian Far East: Kamchatka, Kuril Islands, Yam Islands and Sakhalin. Lately the researchers spend their field season mainly on Medny Island and Tuleny Island (Sakhalin), other rookeries are monitored by an autonomous photo registration system.