Expedition of Pacific Research Institute of Russian Academy of Science and Moscow State University finished the traditional research of whales in the protected water area of the Commander Islands Nature Reserve.
Before leaving for the mainland, the Senior Researcher Ivan Fedutin and his colleagues met our team in the visitor center of the nature reserve to have a cup of tea and speak about interesting observations made during nearly two months of work in the sea.
The participants of the expedition visiting the Commander Islands Nature Reserve office
This year Ivan Fedutin's expedition was accompanied by Olga Titova from A.N. Severtsov Institute of Ecology and Evolution and three volunteers Vitaly Larchenko from Moscow, Tatyana Pridorozhnaya from Yuzhno-Sakhalinsk and Mikhail Barabanov from Luxemburg.
The group based in Poludennaya Bay on the western part of Bering Island. The first whales to be registered there were three meat-eating killer whales, which entered the bay late at night and attacked a seal, most probably a harbor seal, right near the researchers’ ship.
Killer whales near Bering Island
Regardless of the poor light, the animals were caught on a picture and identified. They turned out to be a familiar killer whale pod, which came from Avacha bay on southeastern coast of Kamchatka.
Meat-eating orcas appeared again in two days. During a walk along the tidal zone, the researchers found remains of Baird’s beaked whale cub. This species can be found around the islands all year round.
The dorsal fin thrown out by the see had teeth marks and the animal was killed recently. This is another evidence that killer whales hunt around the Commander Islands. “Skin of the majority of Baird’s beaked whales met during the expedition had old and fresh scars of orca teeth. It is accurate for both adults and cubs. It seems that killer whales hunt these whales not only near Japan but also on the way towards the Commander Islands and even right here in the water area,” said Ivan Fedutin.
Resident community of Baird’s beaked whales
Baird’s beaked whales are among the main objects of the research together with killer whales and humpbacks since 2007. This time there are unusually low numbers of humpback in the water area of the largest marine nature reserve in Russia. Only seven of them were identified, though usually the researchers identify about one hundred. Number of killer whales is moderate and Baird’s beaked whales are very numerous. The group decided to concentrate on these mammals.
This year there surprisingly few humpbacks around the Commander Islands
It seems that a provisional resident community of Baird’s beaked whales has formed in the water area of the islands, as the whales come here regularly every year. Researchers identify the individuals by peculiar patterns and scars on the body.
The familiar whales, judging by their behavior, know well local waters. They frequent shallow waters, which is uncharacteristic for this species, even when they come here for the first time. Usually they dive as deep as 1 km, where they hunt squids and deep-water fish. The Commander Islands beaked whales like shallow zones with depth of 300 meters and even 70 meters sometimes.
“What do they eat there? For now, I do not know. Most likely, they hunt some kind of dish, as trout, halibut or red bass. But the most important thing is that they know the behavior of the fish and enter shallow waters on purpose. It means that we can speak about a cultural tradition of sort formed among the Commander Islands resident beaked whales,” said Ivan Fedutin.
Baird’s beaked whales are seen around the Commander Islands all year round
It is interesting that females and cubs prefer the shallow waters, as they need to save energy to feed the baby and themselves.
Dall’s porpoise were frequent as well. They are a background species and their numbers in the water area depend on migrations of small fish. Moreover, the research group registered a low number of minke whales and high number of sperm whales, which is unusual for a summer season.
The full report about the research, including accurate data on numbers of the registered whales, will be handed to the nature reserve in the end of 2019.
Photos courtesy of the participants of the expedition.