When you live at one of the most isolated corners of the planet, a dog really is man's best friend.
And when a hungry polar bear lumbered ashore to forage for food among the rubbish bins at a weather station, the dogs of Bely Island off the tip of the Yamal Peninsula in Siberia risked their lives to prove their worth.
Without fear of their giant adversary, who could have killed them with a single swipe if it wanted to, they charged forward to protect the few human inhabitants of the remote spot from the powerful beast. First one, then two, and finally a third dog joined the fray, barking and growling at the polar bear.
Although the polar bear did not exactly beat a hasty retreat, it came no further inland after encountering the hostile 'welcoming' committee and shuffled off elsewhere.
The weather station at Bely Island has been there since 1934. The four workers at the station send weather information to Moscow every three hours and polar bears are fairly frequent visitors.
The man who took these remarkable photographs, Sergey Anisimov, 50, was invited to the weather station by the Government of Yamalo-Nenets Autonomous Okrug, whose officials were travelling there to examine a newly built trading station for deer-breeders.
On the island is a memorial stone there dedicated to soldiers and sailors killed during World War Two. There is a Northern Sea Route close to the island and during the war bodies of sailors from sunken ships would wash up on the shore and then be buried inland.
Several Russian Orthodox Priests had also travelled to the island to consecrate the memorial stone. Mr Anisimov said: 'We flew to the station by helicopter. And we noticed a bear when we flew closer to the station.
'The bear was digging into boxes of old things, probably rubbish, looking for some food. When we got out of the helicopter we noticed that the bear came closer until it was only about thirty metres from us.
'The dogs tried to protect us and we fired a signal pistol to try and scare it away. Eventually it gave up its advance and just lay down. There were also weather station workers near us and ready with the guns to scare the bear away.
'When we flew away the bear was still there and was watching us with sad eyes.' Bely Island is a relatively large island in the Kara Sea off the tip of the Yamal Peninsula, Siberia, Russia.
It covers an area of 1,810 square kilometres. It is covered tundra but some dwarf shrubs also grow on the island. It is separated from the mainland by the Malygina Strait, an eight to ten kilometre wide sound which is frozen most of the year.
The island belongs to the Yamalo-Nenets Autonomous Okrug which is the northern part of the Tyumen Oblast administrative division of Russia.