Lake Baikal seal, Nerpa, Baikal seal, Lake baikal seal, Nerpa
The Baikal seal, Lake Baikal seal or nerpa (Pusa sibirica ), is a species of earless seal endemic to Lake Baikal in Siberia, Russia. Like the Caspian seal, it is related to the Arctic ringed seal. The Baikal seal is one of the smallest true seals and the only exclusively freshwater pinniped species. A subpopulation of inland harbour seals living in the Hudson Bay region of Quebec, Canada (Lacs des Loups Marins harbour seals), the Saimaa ringed seal (a ringed seal subspecies) and the Ladoga seal (a ringed seal subspecies) are found in fresh water, but these are part of species that also have marine populations.
The most recent population estimates are 80,000 to 100,000 animals, roughly equaling the expected carrying capacity of the lake. At present, the species is not considered threatened.
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NocturnalNocturnality is an animal behavior characterized by being active during the night and sleeping during the day. The common adjective is "nocturnal",...
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CarnivoreA carnivore meaning 'meat eater' is an organism that derives its energy and nutrient requirements from a diet consisting mainly or exclusively of a...
A piscivore is a carnivorous animal that eats primarily fish. Piscivorous is equivalent to the Greek-derived word ichthyophagous. Fish were the die...
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SemiaquaticSemiaquatic animals are those that are primarily or partly terrestrial but that spend a large amount of time swimming or otherwise occupied in wate...
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PrecocialPrecocial species are those in which the young are relatively mature and mobile from the moment of birth or hatching. Precocial species are normall...
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NatatorialNatatorial animals are those adapted for swimming. Some fish use their pectoral fins as the primary means of locomotion, sometimes termed labriform...
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TerrestrialTerrestrial animals are animals that live predominantly or entirely on land (e.g., cats, ants, snails), as compared with aquatic animals, which liv...
Among animals, viviparity is the development of the embryo inside the body of the parent. The term 'viviparity' and its adjective form 'viviparous'...
A territory is a sociographical area that which an animal consistently defends against the conspecific competition (or, occasionally, against anima...
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PolygynyPolygyny is a mating system in which one male lives and mates with multiple females but each female only mates with a single male.
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SolitaryNo
Not a migrantAnimals that do not make seasonal movements and stay in their native home ranges all year round are called not migrants or residents.
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starts withBaikal seals are tiny seals that are members of the family Phocidae. They are native to Siberia and live only within Lake Baikal, from where their common name comes. They are the only type of freshwater seal type and it is still unknown how they arrived in the lake, thousands of kilometers from a seal’s traditional habitat of the sea. The theory is that seals went along the Yenisey and Angara rivers to the Baikal and settled there. The existence of an underground channel between the lake and Lena River and the lake was also proposed, but no scientific basis has been found for this.
The Baikal seal is almost always seen in Lake Baikal in Russia, the world’s deepest lake, though sometimes it is seen in rivers flowing into and out of the lake. It is only found in freshwater. During winter it uses breathing holes, when the lake is nearly completely covered with 80 to 90 cm thick ice.
Baikal seals live solitary lives, but several of them may gather and share access holes, also sometimes gathering where there is the most favorable habitat. In spring, the time they feed the most, from 200 to 500 individuals will gather, first the juveniles, then adult males, followed by new pups with their mothers. Large groups will also form on the shores of the lake in summer. During winter when the lake is frozen, the seals maintain breathing holes. When the ice starts to thaw, seals gather around larger holes to feed and hunt, mainly at twilight and during nighttime. Baikal seals are dispersed most widely during the winter months. Around the first day in April, they begin to congregate in order to feed near fresh openings where ice has melted. They move in May to the lake’s north end, staying there until they molt. In summer they move to the lake’s southeast corner and use the shore and rocks for hauling out. In autumn, they begin to move back to the areas where the ice is forming.
Baikal seals are carnivores (piscivores), they feed mainly on fish species that have no commercial value for humans, and juvenile seals sometimes also eat amphipods.
Baikal seals have a polygynous mating system, which means that one male mates with multiple females. Breeding occurs in the spring, usually in mid-April to early June. There is a brief period of delayed implantation, and gestation is for about nine months. Pups are born from mid-February to March on the lake ice. Usually one pup is born, though twins are not unusual. In the case of twins, both usually survive until weaning and then remain together for some time. The mothers nurse their pups from 2 to 2.5 months, though not in the southern area of the lake, where ice breaks up earlier. The pups in the south, being weaned prematurely, are smaller. Females typically reach sexual maturity between 3 to 6 years old and males between 4 to 7 years old. Females can breed until about 30 years old.
Baikal seals have been hunted for a very long time for pelts, oil and meat. Such harvesting continues today, although at such a level that it is believed not to threaten the species’ survival. But pollution of the lake is a threat, with this ‘pearl of Siberia’ affected by towns and factories on its shores, which pollute the water with industrial waste and sewage, and the use of pesticides and fertilizers on the agricultural land nearby. Disease is also a threat; an outbreak in 1978 and 1988 of the Phocine distemper virus caused the deaths of an estimated 6,500 seals, and the virus is still alive within the population. Furthermore, global warming threatens the deterioration of the quality of the habitat of the Baikal seal, and may cause a population decline.
According to the IUCN Red List, the total Baikal seal population size was estimated to be around 108,200 individuals in 2013, with an estimated pup production of 23,600 individuals. Currently this species is classified as Least Concern (LC) and its numbers today remain stable.
Being piscivores, these animals affect fish populations in their range. Baikal seal is the crown of the Lake Baikal’s great ecosystem and its only mammal.
