Known for their musky odour when in season, they are said to be truly Arctic animals thanks to their insulated thick brown hair and woolly undercoats. Picture: dizst.livejournal.com

A baby boom in a Siberian reserve has created the world’s largest collection of musk oxen in captivity.

Known for their musky odour when in season, they are said to be truly Arctic animals thanks to their insulated thick brown hair and woolly undercoats.

At one time they became extinct across parts of Europe and Alaska, but were successfully re-introduced and now are most commonly found in Canada and Greenland.

And whilst they are also found living in the wild across Arctic Russia, the 120 or so within in the Gornokhadatinsky Reserve is the largest housed in captivity.

At the time of calving the adults go deep into the reserve, making it almost impossible to see any new arrivals. Picture: Government of Yamalo-Nenets Autonomous District

In the last few days a herd has appeared with more than 20 calves, with exact numbers unlikely to be counted until the summer. According to the gamekeeper Grigory Nozdrachyov, at the time of calving the adults go deep into the reserve, making it almost impossible to see any new arrivals.

Musk oxen and reindeer are the only hoofed mammals in the Arctic that survived the last Ice Age. With a slight resemblance to a bison, it is noted for the strong odour the male gives out during the mating season to attract females.

There are large herds of the oxen on Taimyr, with an estimated population of about 8,000, and in Yakutia, also known as the Sakha Republic, where more than 1,000 live. In both these locations the animals live in the wild and not in a controlled nursery like on Yamal.

According to the last census of the animals in 2014, there were more than 120 of them now living within the reserve, and over 70 outwith the fences. Picture: dizst.livejournal.com

The reserve functions almost like a nursery, to help preserve the species in the region, with the oxen allowed to roam around two vast fenced-in enclosures, spanning 525 hectares and 329 hectares.

A group of 43 musk oxen first arrived at Gornokhadatinsky from Canada in 1997, with 23 placed in one of the enclosures and the other 20 released into the wild.

According to the last census of the animals in 2014, there were more than 120 of them now living within the reserve, and over 70 outwith the fences.

The oxen will be released into the outside world once their numbers are sufficient enough within the confines of the park.

While the animals have enough food and the Siberian climate suits them perfectly, there are a lot of predators within their territory - including within the controlled reserve itself.

The reserve functions almost like a nursery, to help preserve the species in the region, with the oxen allowed to roam around two vast fenced-in enclosures, spanning 525 hectares and 329 hectares. Pictures: Yamal Region

Vyacheslav Kozlovsky, head of the organizational works in the nature reserve, said: 'The bear is the only predator that after a long hibernation in the pursuit of sustenance gets in without any obstacles.

'The enclosures have created are no an obstacle to it. May is the most 'criminal' period for us, with bears causing vast damage.'

Workers within the reserve will spend this month keeping an eye on the oxen and checking the perimeter of the territory but, despite this, not all of the animals will survive.