The spring breakup is already underway in Alaska’s Porcupine River and it caught one herd of caribou by surprise. According to the CBC, a local resident recorded video of the animals trapped on fast moving ice floes as they drifted near shore. River watch teams from the Alaska Division of Homeland Security and Emergency Management also sighted several animals waiting patiently on their temporary rafts.
“Basically, this time of year the porcupine caribou herd is migrating north and the only real major river they cross that runs east-west is the Porcupine River, and it breaks up this time of year,” North Yukon Fish and Wildlife biologist Mike Suitor told GrindTV. “So it just depends on where the herd is with its migration when the river breaks. This year, a large herd actually was at or near the river when the river started to break.”
It is quite common for groups of caribou and other animals to find themselves trapped on the river. Not all of them will survive, but thankfully caribou are well-equipped to handle a short swim. The large ungulates actually have two layers of fur covering their bodies. In winter, caribou sport a long and very thick top layer of guard hairs that insulate the animal and help make it buoyant. Although caribou are not likely to survive a long crossing, those close to shore are more than capable of reaching land safely.
“We’ve seen some run off the ice and we’ve seen another bunch of caribou jump off the ice and run up the bank,” Dayna Lord, who shot the video, told the CBC. “Yeah a lot of people feel bad, but it’s just something that happens every year.”
Porcupine caribou are a subspecies of caribou named after the Porcupine River, which runs through much of their range. Their total numbers are estimated to be around 170,000 individuals. Every year the animals migrate over 1,500 miles from their winter habitat to their calving grounds near the Beaufort Sea, the longest migration of any land mammal in the world. Biologists have often observed caribou attempting to cross half-frozen rivers already in the process of breakup, and it is not known whether the animals are unaware of the danger, or are simply being driven forward by instinct.
You can watch the video below:
Image courtesy Alaska Division of Homeland Security and Emergency Management