Reproduction

Births occur between February and March in a den which the females have hollowed in the ice.

They give birth to their pup after a 9 month gestation period. The female gives birth in an icy den. At birth they have a wooly white coat. Twins are possible and not considered uncommon.

A pup will take its first swim at 3 weeks old and they gain the silvery grey adult fur at 6-8 weeks old.

They suckle for 2 to 2.5 months old before weaning. As the pups are raised on the ice some wean earlier as the ice to the south begins to break up earlier.

Soon after weaning the adults take to the water and mate to produce next season's pup. After mating their is a short period of delayed implantation before the pup starts developing. While considered polygynous it is not uncommon for pairs to mate multiple years in a row.

Females achieve sexual maturity at 3-6 years old while males achieve this between 4 and 7 years old.

An adult female will continue breeding until 30 years of age.

Behavior

Outside of breeding season the Baikal seal is primarily solitary.

They may dive for up to 43 minutes at a time. These may take them to depths of up to 100m (328ft) deep.

In late spring the Baikal seals come to the ice and molt their fur. If the ice has melted by this point they complete this on shore.

Throughout winter the lake is covered by ice and they tend to restrict their movements in the water to keep close to their breathing hole. These breathing holes are kept open by scraping them with their claws.

For winter the population disperses with males scattered throughout the lake, non-breeding females on the east shore, juveniles on the west shore and pregnant females remaining on the ice.

Predators and Threats

At the shoreline they will face predation from bears. These are the only major predator listed for this species.

Pups are hunted each year for their skins and adults for their meat, pelt or oil. While they were previously used for human consumption they are primarily used for animal feed these days.

Baikal seals feed on a range of commercially important fish and as such are persecuted by fisherman.

A significant pressure on their population is pollution and new viruses. Canine distemper has led to a significant decrease and is thought to have been transmitted to them on the shore by dogs.

Their reliance on ice makes them vulnerable to climate change.

Quick facts

With a lifespan of up to 56 years it is thought the Baikal seal may have the longest lifespan of any pinniped.

Locally the Baikal seal is referred to as the nerpa. This means seal in Russian.

Baikal seals are thought to have been isolated from other species of pinniped for 500,000 years.