Vladimir Dobryakov said the female bears, named Varya, Manyasha, Lyalya and Lyusya, were making a 2,800-mile trek from Irkutsk to Vladivostok, RIA Novosti reported Monday.
"It took us eight days to cover the distance ... which was, of course, a lot of strain for the animals," Dobryakov said.
Dobryakov said he attempted to keep the bears awake with strong tea and chocolate candies, but the strain of travel coupled with low temperatures caused the bears to go into hibernation.
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