Tag Archives: american black bear

Baby, It’s Cold Outside

Winter has arrived in the Northeast and snow is in the forecast. While we are piling on the cozy layers and feasting on soup and hot chocolate, outside temperatures are dropping and food for wildlife is getting scarce. Animals across the region are tackling the season head-on and have some impressive strategies to cope with winter conditions.

In the winter, snowshoe hares completely transform, their fur changing from brown to white for better camouflage in the snow. They spend their time eating and hiding which helps to conserve energy for their encounters with predators, such as the lynx. Further south, the New England cottontail uses its brown coat to blend into thick underbrush, and uses snow as a ladder to reach higher shoots, seedlings and twigs.

Have you ever wondered where amphibians and reptiles go in the winter? Most frogs, turtles, and snakes dramatically decrease their activity and enter a state of brumation, or dormancy, where their temperature drops and the heart rate slows down dramatically. Many turtles will bury themselves in mud at the bottom of a pond and absorb oxygen through their skin from the surrounding water. Wood frogs are even capable of freezing solid under leaves in forested areas. They are able to do this by filling their cells with a sugary substance that acts like antifreeze. The frog’s heartbeat stops and stays dormant all winter until they thaw again in spring!

A piping plover and chick by Kaiti Titherington/USFWS

For many birds, the cold is just too much to bear. Like many of us in the winter, migrating birds including the piping plover, leave their homes on the chilly northern coast and take a vacation down south to the warmer shorelines and sandy beaches. Most piping plover are already in their vacation nests by mid-September and come back to work (and mate) by mid-April. Bird migrations vary in length, but some range from hundreds to thousands of miles each year.

An American black bear in a tree. Photo by Courtney Celley/USFWS

If long distance migration isn’t your thing, why not just sleep through winter like the American black bear? Bears aren’t true hibernators, but they can doze for up to 100 days at a time by slowing their metabolism and dropping their core temperature. Bears usually put on fifteen pounds a week during the fall to prepare for their long nap and stretch without food.

As Andrew King took this shot, an Indiana bat flew beneath a large hibernating cluster of Indiana bats on the ceiling of Ray’s Cave, IN (taken pre-white nose syndrome.)

The Indiana bat, a true hibernator, accumulates layers of fat and spends months tucked away in its hibernaculum, like a cave or mine. Throughout winter, bats periodically rouse to move between hibernacula, before their heart rate and body temperature is dramatically lowered to conserve energy. Sadly, white-nose syndrome is plaguing bat hibernacula and causing populations of bats to plummet. Learn more about white-nose syndrome here.

A ruffed grouse in the snow by Head Harbor Lightstation/ Creative Commons

Ruffed grouse are non-migratory birds. They stick out the winters in their usual homes in a protected thicket or burrowed in the snow.  In the late fall, feathers begin to grow on their legs to protect from the cold and help conserve body heat. Pectinations (fleshy comb-like projections along their toes) help them walk on soft snow, roost and burrow. Down feathers allow birds to trap air against their body to stay warm, and many birds will even cuddle together to keep warm.

Swallows cuddle up to keep warm. Photo by Keith Williams/ Creative Commons

We can learn a thing or two from wildlife this winter. Cuddling, sleeping, or vacationing through winter doesn’t sound half bad, especially if you’re not a fan of winter weather!

Wildlife Hunger Games

thomas barnes

I’m Tom, the Fish and Wildlife Service’s new communications intern. If I’m not out fetching coffee, I’ll be sharing important or entertaining conservation stories here every Friday. Credit: USFWS

Whether you’re in a post-Thanksgiving turkey coma or eating popcorn at the premiere of “Catching Fire,” food is on everyone’s mind, wildlife included. And for good reason — animals across the Northeast are preparing to sustain themselves during the coming winter months.

Temperatures are dropping and food is getting scarce. Of course, wildlife have adapted in numerous ways to deal with long winters.

Have you ever wished you could sleep the winter away? I certainly have. Many animals, like the American black bear (Ursus americanus), spend the winter hibernating. We actually call their winter denning “dormancy,” since bears aren’t true hibernators, and some might not den if food is available. After bulking up during the fall, putting on up to anywhere around 15 pounds a week, a black bear can doze for up to 100 days at a stretch by regulating its metabolism. Its body temperature drops by around 12 degrees, and by midwinter, its heart rate can drop as low as only eight beats per minute.

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The American black bear spends autumn bulking up for its winter dormancy.
Same with me. Credit: USFWS.

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Hibernating bats, like the northern long-eared bat, are prone to White Nose syndrome here in the northeast. Credit: USFWS.

Black bears aren’t the only ones holing up for winter. The northern long-eared bat (Myotis septentrionalis) typically increases its body weight by 35 percent or more before retreating to a hibernaculum. Throughout winter, bats periodically rouse anywhere from a few days to weeks to move between hibernacula, before their heart rate and body temperature is again dramatically lowered to conserve energy. Sadly, a disease caused by a cold-loving fungus has swept through these hibernation sites, causing populations of the bats to plummet, dropping 99 percent at some sites across the Northeast.

Instead of taking shelter during the winter, the rufa red knot (Calidris canutus rufa) takes wing — sometimes flying up to 9,300 miles to reach its wintering grounds in Chile and Argentina. Researchers nicknamed one particular red knot “Moonbird,” after they found it had flown 242,350 miles in 13 years, more than the average distance from the earth to the moon. That’s more than my car could drive, certainly. To make this intercontinental migration twice a year, these shorebirds time their stopovers with the spawning season of clams and crabs along the way, sometimes flying 1,500 miles at a stretch.

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Red Knots sometimes winter as far away as South America! Credit: USFWS.

The New England cottontail (Sylvilagus transitionalis) stays active during the winter, foraging for food around its thicket habitats. In fact, snow cover allows the cottontail to reach higher foods than in the fall or summer. Shoots, seedlings, bark and twigs of young trees like birch and aspen are all on the menu. Compared to their summer ranges, these rabbits have to travel much more widely to find food.

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Can you spot the New England cottontail? It depends on its thicket and young forest to escape both the eyes of predators and people that read blogs. Photo via Flickr.

Check out what these other northeast animals do in the winter!

How will you be spending this winter? Hibernating like the northern long-eared bat, or flying south like the rufa red knot? For me, this day after Thanksgiving, I may just stick to the theater.

Tom can be reached at thomas_c_barnes@fws.gov.