The melting of polar ice caps has reduced the population of polar bears on Russia's remote northern islands, with the predators being forced to subsist on sea kelp and small birds because their natural prey have fled, a researcher said.
The waters around the Franz Josef Land archipelago changed from a continuous ice sheet 100 years ago to persistent stretches of ice 20 years ago, but "in recent years, the aquatic area completely clears of ice during summer months, with only icebergs to be seen," said Roman Yershov, head of the Russian Arctic nature reserve, Interfax reported Sunday.
Seals, the polar bears' main prey, have retreated together with the ice, disrupting the animals' natural habits and diet, he said.
The polar bears now have to stay on the shore, feeding on small birds and their eggs, and on sea kelp, he said.
Franz Josef Land, which is uninhabited by humans, is also home to walruses and large colonies of birds, but concerns that climate change may disrupt the archipelago's ecosystem have been raised with increasing frequency in recent years.