Sounds Wild
e-Library Multimedia

Alaska Hare

On a spring day in Southwest Alaska, the snow is melting fast on the tundra. An enormous white rabbit darts from a willow draw and bounds away. It's not a snowshoe hare, it's Alaska's other native, wild hare, the tundra hare. These giant tundra bunnies are also known as the Alaska hare, but most people simply call all hares rabbits.

Found only in Western Alaska, the Alaska hare is among the largest hares in the world. While snowshoe hares average two or three pounds, Alaska hares are six to 12 pounds, about three times as big as snowshoe hares. Alaska hares have black tipped ears, unlike the smaller snowshoe hares.

Fish and Game's statewide Small Game Program is studying Alaska hares, an important subsistence and ecological resource in Alaska. Biologists with the Program plan capture and radio collar several Alaska hares to learn more about daily movements, sources of mortality, and potentially even productivity and survival of young hares, known as leverets. They also plan to try and develop a non-invasive abundance estimation method for this largely nocturnal and species using their pellets or droppings.

Click here to view this episode in separate page.

Click here to view this episode in separate page.

Arctic Ground Squirrels

On a summer day a bird-like chirp travels on the breeze across a sandy river bank. It's not a bird, it's an arctic ground squirrel. Arctic ground squirrels spend most of their lives hibernating. In summer, they have just about 100 days to mate, raise a litter of pups, and fatten up for another 270 days of sub-zero hibernation.

Males come out in the first and go back last. They rouse from hibernation in March, but they stay underground for about three weeks, eating from a food cache they stored the fall. In April, they emerge from the den in the spring daylight in search of a mate.

The females are out around the second week in April and within a day or two, they're pregnant. They gestate five to seven pups for about three weeks, they're born tiny and hairless and nurse for about six weeks. Then they fatten up quickly on the vegetation at the summer's peak.. By the end of July, the females and young head back to the burrow. The males follow in mid to late September.

Arctic ground squirrels are extreme hibernators. Their body temperature drops to minus 3 degrees Celsius, below the freezing point of water. They are super cooled, but they don't freeze. Their heart rate slows to a few beats per minute and they breathe once every few minutes. Come spring, with no external cues like light or warming soils, they begin the whole cycle again.

Click here to view this episode in separate page.

Baby porcupines

In the lush greenery of an Alaska forest in spring, a mother porcupine is nursing her baby. The baby porcupine, called a porcupette, is just about a foot long and weighs a little more than a pound. He was born last week, and he's fully capable of following his mother around the forest as she forages on the lush green vegetation. He's able to eat a little as well. It'll be a few weeks before he'll be able to climb trees, and he'll continue nursing through the summer.

Porcupines have an extremely long pregnancy, about seven months. The gestation period is extremely long for a rodent, twice the time for a beaver, the largest rodent in Alaska. Porcupine moms give birth to just a single baby a year. Its eyes are open and its body covered with long grayish-black hairs and quills. The quills are not a problem for the mother at birth as the porcupette is encased in a little sack called a caul. Within a matter of hours the quills dry and serve as protection.

During the summer the young stay close to their mothers, learning about the den sites and food trees in the mother's home range. Toward the end of summer they start to spend more time apart. By October, when the female mates again, the young are fully weaned and wander off to face the winter alone.

Click here to view this episode in separate page.

Bat monitoring

On a summer night a bat is flitting about the street light, catching moths and insects drawn to the light. It's almost certainly a little brown bat, the most common and widely distributed bat in Alaska.

Little brown bats eat at average of half their body weight in insects a night; a lactating female may eat as much as 110% of her body weight. A female bat gives birth to only one pup in the early summer. That's a low reproductive rate, but little brown bats can live more than 30 years - an amazing lifespan for a small mammal. Mice and other small mammals rarely live longer than a year or two.

In early summer, little brown bats sexually segregate. If this bat is a female has a pup, she's part of a maternity colony - a group of females and young that roost together. In Interior Alaska, these have been found ranging in size from 70 to 200 bats. A large maternity colony discovered in Juneau was home to more than 1,000 bats in the summer of 2013.

Fish and Game has established a network of year-round acoustic monitoring station across Southeast Alaska to learn more about when bats emerge in spring, when they disappear in the fall, and to compare seasonal activity patterns across the region. Biologists are trapping and radiotagging little brown bats to learn more about the timing of reproduction and migration, the locations of maternity and day roosts, and where little brown bats go in winter.

Click here to view this episode in separate page.

Bats

On a cool fall night, a biologist in Southeast Alaska is monitoring for bats. She's set up a mist net, and bats are flying overhead. A bat detector hears the ultra-high-pitched echolocation calls that bats use to find their insect prey and converts them into a range that people can hear. She's caught a bat in the net, and it vocalizes with chittering squeaks as we untangle it, then it calms down as we tag and release it.

Alaskans sometimes find dead bats, and bat researchers with Fish and Game want dead bats. Use gloves or a plastic bag to collect the dead bat and put it in a ziplock bag, and put that into another ziplock and seal it. Label the outer bag with the date, location and your contact information and keep it cool, but do not freeze it. The fish and Game website has contact information for local offices and bat researchers. The bat will be tested for pathogens like rabies, and for bat diseases like white nose syndrome, which has killed little brown bats in the Lower 48, and which has not been detected in Alaska. Continued monitoring will help biologists understand the status of bats in Alaska.

Click here to view this episode in separate page.

Beavers disappear

On fall day a canoeist rounds a bend in a slough, surprising a swimming beaver. The beaver does what beavers do, it smacks the water with its tail and disappears beneath the surface. That's a warning to other beavers that an intruder is about.

Beavers once pulled another kind of disappearing act on a much larger scale. Beavers are abundant in Alaska, and centuries ago, they were abundant throughout North America, Europe and northern Asia - but that changed. Beavers have long been valued for their fur and for castoreum, a waxy secretion that was used to make perfume and medicine. A desire for pelts and castoreum, and more importantly, competition for habitat, contributed to their disappearance from Europe.

Beavers were once found throughout Europe as far south as Spain and Italy, but disappeared as people claimed the river valleys for agriculture. Beavers disappeared from England in the 13th century. Even the remoter regions of Europe such as Norway, Sweden and Siberia saw the decline of beavers, and by the 1800s, beavers were essentially gone from Europe.

There was no shortage of beaver pelts, however, as the Hudson Bay Fur Company was exporting more than 200,000 pelts a year from North America. By the dawn of the 20th century, the beaver was nearly gone from North America as well.

Since the 1930s, widespread conservation efforts have led to a return of the beaver to much of its former range in America. A small population of beavers in Norway, protected on private land, increased as Norway extended protection to beavers throughout the country. Russia imported beavers from Norway and from America, began captive breeding, and re-introduced beavers, as did Finland and Sweden. Beavers made something of a comeback in Europe, and these animals are a mix of the American and the original European species.

Click here to view this episode in separate page.

Beringian creatures

Alaska wolves are more closely related to Siberian wolves than they are to wolves in Minnesota. That seems surprising, since Alaska is connected by land to the Lower 48, and divided from Asia by the Bering Sea. But that wasn't always the case.

Just a few thousand years ago, Alaska was separated from the rest of North America by vast continental glaciers, enormous ice sheets that blocked passage to the south. The Ice age continental glaciers contained so much water that sea levels world-wide were almost 300-feet lower than today. The Bering Sea was dry and Alaska and Asia formed a landscape known as Beringia, a great plain that stretched from Eastern Europe to the Yukon.

The famous, now extinct prehistoric animals like mastodons, mammoths, giant bears, and saber-tooth cats roamed this landscape, but there were other familiar animals present as well, animals that still live in Asia and Alaska - muskox, caribou, moose, wolves, brown bears, wolverines, ravens, and lemmings.

Two animals that live today can be thought of as Beringian creatures - the grey-headed chickadee and the Alaska blackfish - which are found only in Siberia and northern Alaska. Even more striking is that the Alaska Blackfish is also found in lakes on three islands in the Bering Sea -St. Lawrence, St. Matthew and Nunivak Islands - islands that would've been low hills on the Beringian landscape.

Click here to view this episode in separate page.

Click here to view this episode in separate page.

Cat travels

On a sunny spring day at the Tetlin national Wildlife Refuge near Tok in Interior Alaska, a lynx stands on a trail in a snowy forest calling for a female. This big male is exploring the home ranges of neighboring lynx, looking for a mate. Researchers with the Tetlin refuge are studying these northern wild cats and their dietary mainstay, snow shoe hares, and they've equipped 22 lynx with tracking collars since March of 2015. They've also set up a series of remote, motion-triggered trail cameras to capture video footage and audio clips of lynx. This lynx doesn't know it, but he's on camera.

The collars have also enabled the biologists to find mother lynx in early summer and document lynx dens. They've visited five dens - all in very thick underbrush in prime snow shoe hare habitat - and examined and documented 24 lynx kittens.

Lynx weigh between 20 and 30 pounds but because of their thick and luxurious fur coats, they look bigger. They have massive paws that act like snowshoes and enable them to travel easily on deep, light snow in search of their favorite prey, snow shoe hares. They also eat red squirrels, grouse and other birds they catch opportunistically, but hares are their mainstay. Hare numbers shift in roughly ten year boom and bust cycles and hares may be ten times more numerous in peak years. When hare numbers crash, lynx may travel long distances in search of food.

Click here to view this episode in separate page.

Chipmunks

On a trip to the Yukon, I see a small, striped animal I know well from my childhood in Oregon. It's a chipmunk. The chipmunks running around this campground near Whitehorse are least chipmunks, Tamias minimus, the northernmost chipmunk in the west. Weighing just an ounce or two, they are the smallest chipmunks and also the most widespread chipmunk in North America. In the Yukon they're found almost as far north as the Arctic Circle, but they don't range west into Alaska.

The scientific name for chipmunks, Tamias, means storer. Alaska is home to six kinds of squirrels, and Alaska's most familiar tree squirrel, the red squirrel, shares the name "storer" as well as the trait. Like chipmunks, red squirrels don't hibernate and are active throughout the winter. They survive by eating their extensive cache of stored food. Cones are the most familiar squirrel food, but they also store mushrooms, fruit and seeds.

The red squirrel is the smallest North American tree squirrel, weighing about half a pound. Also known as the chickaree or pine squirrel, it is found in forested areas across Alaska and Canada and down the Rocky Mountains. Alaska's other squirrels include the Arctic ground squirrel and the Northern Flying squirrel. Marmots are also squirrels, big ground squirrels, which means that Alaska is home to both the smallest tree squirrel and largest ground squirrel, the hoary marmot, which can weigh 20 pounds.

Click here to view this episode in separate page.

The forests of Alaska are home to large predators like bears and wolves, but Alaska is considered to be outside the range of cougars, also called mountain lions and panthers. Cougar populations are increasing in many western states and Canada, and the big cats are expanding their range. The Yukon Territory was considered to be outside the cougar's range until recently. The first confirmed cougar sighting in the Yukon was in 2000. In 2015 two cougars were photographed just outside Whitehorse, and Canadian biologists say there is now evidence of a small, established breeding population of cougars in the Yukon.

State wildlife biologist Nick Demma studies large carnivores. He said expanding mule deer populations could help bring cougars into the state. Alaska used to be outside the range of mule deer, but deer are moving into Eastern Interior Alaska, and have been documented as far west as Fairbanks. Demma said: "Mule deer are a main prey for cougars where they co-exist. Mule deer sightings in the eastern Interior appear to be increasing and because source populations exist for cougars and mule deer next door in the Yukon it is certainly reasonable to expect that cougars could follow an expanding mule deer population eastern Interior Alaska."

Click here to view this episode in separate page.

Click here to view this episode in separate page.

Dall vs Dall's sheep

On a summer day we are hiking up a treeless, rocky hillside in the Burwash uplands of Kluane. As we crest a ridge we see a herd of a dozen Dall's sheep just a hundred yards away. The group immediately bolts, disappearing off the backside of the ridge.

The sheep inhabit mountain ranges of Alaska, the Yukon, the Northwest Territories, and central and northern British Columbia. Dall's sheep favor relatively dry country with a combination of open alpine ridges, meadows, and steep slopes to allow escape from predators that cannot travel as quickly through rugged terrain.

These wild sheep native to northwestern North America are often called thinhorn sheep, and Dall's sheep and Stone sheep are considered to be subspecies, although genetically all are very similar. Bighorn sheep are a closely related species found further south in the American west. Bighorn sheep populations were profoundly impacted by diseases introduced by European livestock.

Is it Dall sheep or Dall's sheep? Both are commonly used. Most scientific journals require the use of the possessive adjective with the apostrophe ess - Dall's sheep. The animals are named for William Healy Dall, a renowned American naturalist who explored Alaska in the decades following the purchase from Russia.

Click here to view this episode in separate page.

Feral Rabbits

In a quiet neighborhood in East Anchorage, something is moving around under a swing set in a back yard. It's a rabbit. It's not a native showshoe hare, it's a European rabbit, the classic bunny rabbit kept as pets and raised for food. This is not a pet; however, it's a feral rabbit, born in the neighborhood last year to rabbit parents that were released to the wild. It's a problem, and many of the people in this neighborhood are unhappy with the bunny boom.

Feral rabbits are a problem in neighborhoods in Anchorage, Juneau, and on the Kenai. Feral rabbits can spread parasites to wild populations of snowshoe hares. They can attract predators like coyotes, wolves or bears into the neighborhoods. They are an unwanted distraction for dogs in the neighborhood, which break away and chase them. In Juneau, rabbits have demolished backyard gardens, and fencing the garden is now a necessity in some areas. Rabbits are a problem for the local animal shelter, as they are expensive to maintain and not particularly popular as pets.

European rabbits have also been released on several islands in Alaska, and have established populations on Kodiak Island, Middleton Island in Prince William Sound, and two islands in the Aleutians.

A female rabbit can breed every 30 days. Rabbits can have as many as 14 babies per litter, and can become pregnant again within a day of giving birth.

Click here to view this episode in separate page.

Fisher

A strange call carries through the night near the Taku River in northern Southeast Alaska. It's a fisher, a cat-size weasel, the larger cousin to the marten and the mink.

Fishers are found in forests across northern North America, from Maine to British Columbia, but the fisher was not historically documented in Alaska. Since the mid-1990s, the fisher has expanded its range into the southern Yukon, and into Southeast Alaska.

The first fisher documented in Alaska was in 1997, just north of Juneau. Biologists suspect the animal accessed the coast from known populations in British Columbia via the Taku River corridor, as the southeast coastline is otherwise separated from BC by mountains and icefields. Between 1997 and 2018, 25 more fisher were documented, all in the Juneau area of northern Southeast Alaska. The animals are expanding their range north and south of the Taku River, and in recent years the distribution is widening up and down the mainland coastline.

Despite the name, the fisher does not fish or eat fish. They eat hares, birds and large rodents, and Fisher are somewhat renowned as one of the few predators that regularly and successfully kill porcupines.

Click here to view this episode in separate page.

Fur farming

I was camped on a tiny island in Southeast Alaska a few years ago, monitoring seabirds in Icy Strait. The island, Entrance Island, is just about a dozen acres in size. On a short walk I came across some rotting lumber and fencing, and as I picked through it, I realized it was the site of an old fur farm.

100 years ago, fur farming was big business in Alaska. It was the third biggest industry in the state, after fishing and mining. Foxes were the most prized, and specific color phases of the red fox and the arctic fox netted more than $100 a pelt, a fortune in those days.

The first fur farm started in Southeast Alaska near Tracy arm in 1901, and by 1929 there were more than 700 fur farms in the Alaska territory, 200 in Southeast Alaska and hundreds more in the interior and on the Aleutian Islands. Islands were popular sites, as animals were fenced by the sea.

More than 45 different species of furbearers were farmed, including skunks, raccoons, rabbits, marten, otters and beavers. Otters and beaver proved too difficult to manage, and while marten were quite lucrative they were difficult to breed in captivity. Martin fur is marketed as sable, but some of the marketing terms were pretty misleading. The skunk's white-striped pelt was dyed black and marketed as "Alaska sable," and dyed rabbit pelts were sold as "Hudson's seal." Long-haired rabbits were sold as chinchilla, although they were not the actual velvety South American rodents known as chinchillas.

1929 marked the beginning of the end for fur farms. Fur prices plummeted in the 1930s during the depression, and fur farming was declared a non-essential industry during the Second World War.

Click here to view this episode in separate page.

Goats

A small plane flies over the green ridges near Valdez. The ridges and mountains are flanked by stunning glaciers, and to the south, the blue waters of Prince William Sound. A biologist aboard the plane is conducting a survey of mountain goats in the area, and she's counted 235 creamy-white goats against the green alpine in this 2018 aerial survey. That helps determine how many goats hunters will be allowed to harvest in this area in the upcoming hunting season. To insure that the harvest remains sustainable, wildlife managers limit the number of goats that may be taken in a defined area, and successful hunters must report their harvest within a few days. In this area in 2018, for example, a total of 12 goat units may be taken. Not 12 goats, but 12 goat units - a billy counts for one, and a nanny counts for two. Nannies are critical to sustaining the population.

Although the goat hunting season here could potentially last from mid-September to the end of January, the biologist can close it as soon as the harvest quota is reached. In 2018, the harvest quota was reached in less than two weeks, and the hunt was closed. Careful monitoring and management will insure goat hunting opportunity in future years.

Click here to view this episode in separate page.

Groundhog Day

Groundhogs are marmots, one of three kinds of marmots found in Alaska. Groundhogs, also known as woodchucks, are the smallest of Alaska's marmots. February second is Groundhog Day, and there's a good reason for that. Groundhog Day falls halfway between the winter solstice and the spring equinox. Groundhog Day has its origins in ancient European weather lore where the mid-winter behavior of some animal, usually a badger or bear, indicates how much longer winter will last; and in the Pagan festival of Imbolg, which celebrated the lengthening days and the early signs of spring.

The American holiday originated in mid-1800s in Central Pennsylvania among German-immigrant farmers. The annual celebration in Punxsutawney, Pennsylvania, is the best known and largest gathering in the U.S. and has been since the 1800s. Those Pennsylvania groundhogs might actually peek out of the burrows mid-winter, but Alaska's groundhogs definitely do not. They're hibernating, and they are serious hibernators.

In summer, a groundhog maintains a body temperature of a hundred degrees, a heart rate of 200 beats per minute, and a respiratory rate of 50 breaths per minute. A hibernating groundhog drops its body temperature to about 35 degrees, barely above freezing, reduces its respiration to one breath per minute, and its heart rate to just four beats per minute.

Click here to view this episode in separate page.

Click here to view this episode in separate page.

Haida Ermine

On a spring day a small brown weasel scurries through the forest on Prince of Wales Island. A few months ago, this little ermine was white - like snowshoe hares, ermine wear a white coat in winter. Now its summer brown, like other ermine across Alaska. But this ermine is a little different. Researchers have learned that ermine on a few islands in British Columbia and southern Southeast Alaska are genetically distinct, and different enough to merit their own name and species designation - the Haida ermine.

it's one of three main ermine species in the world. Researcher Jocelyn Colella, building on work by biologist Natalie Dawson, looked at tissue samples from ermine in Alaska, Europe, Asia and across North America - identifying their genetic makeup. She also compared ermines' skulls. She found that there were three main species: one in Eurasia, one in North America and one found only on Prince of Wales in Southeast Alaska and Haida Gwaii off the coast of British Columbia.

These islands were not glaciated during the ice age, serving as refugia for a variety of animals. Isolated, and adapting to specific environmental conditions, the population became genetically distinct over thousands of years.

The Haida ermine isn't the only animal specific to the area. Marten, a larger weasel, also show the same indicators, as does the Franklin grouse. Black bears in the area are genetically distinct but are not considered a separate species from other American black bears.

Click here to view this episode in separate page.

Click here to view this episode in separate page.

Hibernators

Hoary marmots are one of seven mammals in Alaska that curl up in dens or burrows and sleep through Alaska's cold, dark season. The other mammalian hibernators are Alaska marmots, woodchucks, black bears, brown bears, arctic ground squirrels and little brown bats.

Hibernation is not the same for all animals. Arctic ground squirrels are the deepest sleepers and drop their core body temperatures to 27 degrees Fahrenheit, the lowest known body temperature for a hibernating mammal in the world.

Arctic ground squirrels hibernate alone, but Alaska's marmots hibernate in family groups or small colonies in burrows under rock piles or boulder fields. They insulate their rocky burrows with dry foliage and plug the entrance before they settle in for a six or seven month sleep.

The little brown bat, which is just about half the size of a chickadee, is the tiniest hibernating mammal in Alaska. Bats hibernate in groups, in protected roosts called hibernaculum, in rock crevices, inside tree cavities and root wads, and even in buildings. It is believed that bats in Interior Alaska migrate to moister, warmer parts of the state to hibernate.

Bears are the lightest sleepers, and will wake up occasionally and move around inside the den, shifting their sleeping position. Bears also shift positions to better conserve heat and to prevent pressure sores from developing. Waking a hibernating arctic ground squirrel can take hours or days. Bears, on the other hand, can rouse quickly when disturbed.

Click here to view this episode in separate page.

Click here to view this episode in separate page.

Click here to view this episode in separate page.

Click here to view this episode in separate page.

Jumping mice

On a camping trip I set a small live trap overnight to see what kind of mice or voles I might catch. Over the course of a few nights I managed to catch a western jumping mouse every single night. I commented to my brother that jumping mice seem to be pretty abundant and he countered with an observation that was almost certainly true - that I was catching the same mouse over and over.

Jumping mice are slender, nocturnal rodents that hibernate during the winter. They are quite distinctive looking, with long tails and large hind feet, like a kangaroo that's just four inches tall. There are two species in Alaska, the western jumping mouse and the meadow jumping mouse, which look very similar. As the name implies, western jumping mice are found in western North America, and meadow jumping mice are found across North America, favoring meadows and moist grasslands. Their ranges overlap in British Columbia and Southeast Alaska. They're pretty common, but because they are nocturnal, and they hibernate for half the year, they aren't often seen. They are excellent diggers and burrow, using their powerful hind feet to kick dirt away. They are also good swimmers, which doesn't always end well - they've been found in the stomachs of northern pike.

The jumping prowess of these little rodents is remarkable. When I opened the trap, I bet that mouse sprang six feet in a single bound, then disappeared into the tall grass with a series of short, fast little hops.

Click here to view this episode in separate page.

Long-eared Bat

On a cool spring night, bat researchers on Douglas Island near Juneau are catching bats. A bat detector sounds off when it hears the high pitch echolocation calls of nearby bats. Different bats make different calls, and a graphic representation of the call, an acoustic signature, can help identify the species of bat. Southeast Alaska is home to little brown bats, silver- haired bats, and a few others, including Keen’s myotis. But biologists are learning that Keen’s myotis is likely the same species known elsewhere as the western long-eared bat.

In the 1890s a british Anglican missionary named John Henry Keen, based in northern British Columbia, took a serious interest in natural history. He wrote about insects and animals of the coastal rainforest, and sent specimens back to the British Museum. He described a “brown mouse-eared bat,” found only in Southeast Alaska and British Columbia, which came to be called Keen's myotis. Even at the time it was acknowledged to be very similar to the western long-eared bat, a species found across western north America. Now, two decades into the 21^st century, with tools to examine genetics and the signature calls that bats make, biologist are learning that Keen’s myotis is indistinguishable from the Western Long-eared bat.

Click here to view this episode in separate page.

Lynx

It's feeding time at the Alaska Zoo, and Tuesday is chicken day. When the lynx get their chickens, they respond much like a pair of competitive housecats. When one lynx shows a little too much interest in her neighbors' food, she expresses her displeasure.

Cats the world over show a great many similarities, especially in behavior. They vary in size, of course, and different species have adaptations that suit them for their particular environments. The lynx is the only cat native to Alaska. The lynx is like a bobcat, but modified for northern life. Very large, broad, furry feet function as snowshoes to aid the lynx in winter hunting and traveling over deep snow. Dense, soft fur, and a bib-like ruff keep the cat warm in winter. Like the bobcat, the lynx has a short tail and long tufts on the tip of each ear, but the furry tufts are noticeably longer on the lynx. Most adults weigh from 18 to 30 pounds - males are generally larger than females and can weigh 40 pounds.

The presence and abundance of Alaska's native wild cat is closely tied to snowshoes hares. The production and survival of lynx kittens is strongly influenced by the cyclic changes in snowshoe hares. When prey is abundant, a high percentage of 1-year old lynx produce kittens, as well as older females, and most of the kittens which survive. When prey is scarce, very few yearlings breed, the number of adults breeding declines, and very few kittens survive their first year.

Click here to view this episode in separate page.

Marmot

Late spring in Alaska and marmots are emerging from their winter hibernation. For the past six to eight months, marmots have been sleeping in winter burrows with their body temperature lowered and all bodily functions, like breathing and heartbeat, greatly reduced.

Marmots are big ground squirrels, and they're social animals. A marmot family has its own burrow, but the burrows are located near each other, forming a colony. Alaska is home to three kinds of marmot - hoary marmots, Alaska marmots, and woodchucks. Woodchucks are known as groundhogs in the Eastern U.S. The name woodchuck originated as a Cree Indian word and does not describe the animals' habitat preference or behavior.

Woodchucks and hoary marmot hibernate alone, in the same burrow where they spend the summer. To protect themselves from the cold, woodchucks and hoary marmots plug the tunnel between the outside world and their nest chamber. They emerge in April or early May to find food and mates.

Alaska marmots, in contrast, are adapted to the harsher winter climate of northern Alaska. They hibernate as a group in a special winter den which has a single entrance and is characteristically located on an exposed ridge that becomes snow-free in early spring. The entrance is plugged after all colony members are inside, and no animals can leave until the plug thaws in early May. Consequently, Alaska marmots mate before they emerge from their winter den. These dens are relatively permanent for each colony, and may be used for many winters.

Click here to view this episode in separate page.

Click here to view this episode in separate page.

Mice

One evening my cat popped through the cat door with a limp mouse in his mouth. I was not appreciative, especially since as soon as he dropped the rodent on the mat it sprang to life and darted under the fridge. I could tell it was not a vole or native deer mouse, but a brown house mouse. This invasive species is originally from Asia or northern India and has spread around the globe. That mouse lived in the kitchen for months and eluded both my cats and my attempts to trap it. I'd see it occasionally dashing across the kitchen in a blur, and I learned why it was such a survivor.

For starters, mice are fast. A mouse can run 12 feet in a second. Maybe not as fast as that speedy cartoon mouse, but fast enough to dodge my old cats. Mice are also excellent swimmers. They're pretty tough, too, a mouse can survive fall of eight feet onto a hard surface.

Fortunately, this mouse had no company, because a mouse is sexually mature when it's a month old. A female mouse can become pregnant again within two days after giving birth. A female mouse can have eight litters in its year-long life, with litters averaging four to seven pups. So a single female can potentially produce up to 56 offspring in a year. Mice will reproduce year-round in a stable environment with sufficient food and water.

The mouse in my kitchen must've slowed down in his old age, because one night the cat's incessant meowing brought me to the kitchen, where he proudly stood over the now defeated rodent.

Click here to view this episode in separate page.

Minks: Kodiak's newest invasive species

On an overcast morning at Dog Bay on Kodiak Island, a thin brown weasel darts along the intertidal. It's a mink. Mink are not native to Kodiak, and were introduced to the island around 2013. The introduction was not legal, and the animals are considered to be an invasive species on the island.

State wildlife biologist Nathan Svoboda said the Kodiak Fish and Game office is getting more reports of mink sightings as time goes on. Trappers on the island are also catching them in traps, and while the population isn't exploding, numbers are increasing every year. Svoboda said most of the sightings have been around the town of Kodiak.

Although mink are trapped in Alaska, they are not particularly valuable or sought after. Between 2014 and 2017, the average price paid to a trapper for a mink pelt was just about 10 dollars.

In the 1800s and early in the 20th century, many different species of plants, fish and animals were introduced to new areas of North America, with no thought to potential negative consequences. In many cases, invasive plants, fish and snails have profoundly affected their new aquatic ecosystems.

Once thriving sea bird colonies on a number of islands in Alaska were destroyed when foxes were introduced with the plan that, like mink, they would be harvested for their fur.

Click here to view this episode in separate page.

Click here to view this episode in separate page.

Mountain Lions in Alaska

The forests of Alaska are home to large predators like bears and wolves, but Alaska is considered to be outside the range of cougars, also called mountain lions and panthers. Cougar populations are increasing in many western states and Canada, and the big cats are expanding their range. The Yukon Territory was considered to be outside the cougar's range until recently. The first confirmed cougar sighting in the Yukon was in 2000. In 2015 two cougars were photographed just outside Whitehorse, and Canadian biologists say there is now evidence of a small, established breeding population of cougars in the Yukon.

State wildlife biologist Nick Demma studies large carnivores. He said expanding mule deer populations could help bring cougars into the state. Alaska used to be outside the range of mule deer, but deer are moving into Eastern Interior Alaska, and have been documented as far west as Fairbanks. Demma said: "Mule deer are a main prey for cougars where they co-exist. Mule deer sightings in the eastern Interior appear to be increasing and because source populations exist for cougars and mule deer next door in the Yukon it is certainly reasonable to expect that cougars could follow an expanding mule deer population eastern Interior Alaska."

Click here to view this episode in separate page.

Muskox

Muskoxen, like this baby muskox calling in the Alaska Zoo, represent an important success story in wildlife conservation.

Muskoxen are northern animals, well adapted to life in the Arctic. At the close of the last ice age, muskoxen were found across northern Europe, Asia, Greenland and North America. But after the ice age, the musk ox faced a threat more dangerous than wolves and bears - humans. By the mid-1800s, muskoxen had disappeared from Europe and Asia. By the 1920s, these animals were gone from Alaska as well. Overhunting by local residents was probably a contributing factor. Whalers re-supplying their ships with meat also took a heavy toll in some regions, as did Arctic exploring parties.

By the 1920s, the only remaining muskoxen were found in east Greenland and arctic Canada. International concern about the impending extinction of this animal led to a move to restore a protected population in Alaska.

In 1930, 34 muskoxen captured in East Greenland were brought to Fairbanks. This small herd was then transferred to Nunivak Island, a large island in the Bering Sea about 200 miles west of Bethel. The muskoxen thrived there and by 1968 the herd had grown to 750 animals.

Muskox from Nunivak herd have been translocated to establish new herds, on the Seward Peninsula, on Thompson and Nelson Islands, in the Arctic National Wildlife Refuge, and on Wrangel island and the Taimyr peninsula in Russia. By the year 2000, there were almost 4,000 muskoxen in Alaska. In recent years herds in the Arctic Refuge and adjoining areas have declined somewhat, but other wild populations are growing. This baby muskox is a descendant of the original 34 brought to Alaska from Greenland.

Click here to view this episode in separate page.

Muskox Hair

A muskox calf calls out before his morning feeding at the Alaska zoo. Biologists are studying wild muskox and captive muskox are helping by supplying strands of hair from their shaggy coats. Like the analysis of hair for drug testing in people, hair from animals reveals chemicals, elements like mercury, hormones and environmental contaminants. Stable isotopes of carbon and nitrogen can be detected in hair, correlating to diet and seasonal changes in diet. Reproductive hormones may indicate pregnancy and steroid hormones correlate to stress.

Testing hair from captive muskox with known histories helps biologist understand what is detected in wild muskox.

The fresh green plant growth that wild muskox eat in the spring is more nitrogen-rich than their winter diet. When detected as stable isotopes of nitrogen in a length of hair, this graphs on a timeline as seasonal peaks and valleys. Events like a pregnancy or a stressful winter can be sequenced on a timeline and correlated with other information like weather data and can indicate how environmental conditions might affect the animals.

Click here to view this episode in separate page.

Click here to view this episode in separate page.

Neophobic rats

Man is rats' best friend. Humans provide food and shelter for rodents, but most importantly, humans provide transportation. Rats have long profited from their close association with humans, tagging along as people colonized the Earth. This "commensal" trait is just one of the qualities that have helped rats and mice spread throughout the world.

Three rodent species have caused the most profound problems worldwide: the Norway rat, the roof rat and the house mouse. All breed year-round, have short gestation periods and large litters. They quickly populate new environs and recover rapidly when their numbers are reduced.

One thing that makes rats so successful is their feeding behavior, a sophisticated balance of caution and curiosity. Rats have a strong dive to explore and will thoroughly learn all aspects of their home environment. This inquisitive behavior would make rats easy to trap or poison if it wasn't inhibited by another behavior called neophobia - a fear of new things. Rats will quickly detect but shy away from new objects in their environment.

"It's a perfect strategy for survival," Dunlevy said. "There are always some segments of a population that are at extremes - very cautious or very curious - so one segment or the other will survive or be favored by natural selection."

Click here to view this episode in separate page.

Pikas

The shrill whistle of a pika carries across a talus slope in Interior Alaska. Another pika answers. Pikas are small mammals, not much bigger than a softball. They behave a bit like marmots, scurrying around rock piles and ducking into crevices, but they are related to rabbits, and look like a cross between a rabbit and a little Guinea pig.

Pikas prefer cold climates. In the Lower 48 they are found at high elevations, and pikas in the Himalayas live at higher elevations than almost any animal on Earth, at elevations close to 20,000 feet above sea level. Pikas live in rock piles and talus slopes, finding shelter in the cracks and crevices. Their entire home range is typically just 100 feet or so in size.

Pikas have an interesting behavior - they harvest grasses, flowers, leaves and green plants in the summer and spread the vegetation out on rocks to dry in the sun. They guard their hay piles, because other pikas will steal them. Like squirrels and beavers, they spend the summer months gathering food to store for winter. They do not hibernate, and are active under the rocks all winter, living on their cache of stored food.

Pikas call in the spring to attract a mate. Like marmots, they call as a warning that a predator is about. They also call back and forth in defense of their hay piles and caches.

Click here to view this episode in separate page.

Click here to view this episode in separate page.

Porcupines in Winter

Hiking through the woods on a winter day I come across the tell-tale sign of a porcupine - the crusty snow under a spruce tree is littered with twigs, needles and small branches, nipped off and dropped as the porcupine feeds. She's camped out in the branches up above and from the number of the nip-twigs, she's been there for a while.

The area beneath a winter porcupine tree can become a kind of feeding station for other animals trying to survive. Snowshoe hares come to eat porcupine leftovers, then lynx and coyotes come in for the hares. It's amazing how many different animal tracks you can find in the snow around one of these trees.

Porcupines live within a home range and during winter cold snaps or storms, they den up, sheltering in a rock crevice, root wad, hollow log, or, like this porcupine, up in a tree. They don't hibernate, but grow a thick furry undercoat for insulation beneath their famous quills.

Like North America's other large rodent, the beaver, porcupines eat the soft inner bark of trees known as cambium. They leave distinctive tooth-marked bare patches on tree trunks, where they gnaw away the bark and eat the underlying cambium. In Southcentral they feed on birch and white spruce cambium, as well as spruce needles. In Southeast they eat Sitka spruce needles and twigs, and in the north they may subsist on willow twigs. For SW…

Click here to view this episode in separate page.

Porcupine antibiotic quills

A few years ago my friends' dog got nailed by a porcupine. We wrapped her in a blanket and pulled a dozen quills out of her mouth and muzzle, but we missed one in the roof of her mouth. We discovered it a few weeks later when it came out by itself... on the other side. The quill migrated all the way through her muzzle and emerged point first.

Porcupine quills have microscopic barbs that do more than make them stick in the skin of an attacker; they cause the quill to work itself deeper into the victim. Porcupine researcher Uldis Roze noted similar experiences with migrating quills, including one that worked its way through his arm. Roze was astonished - not by the quill's action, but by what didn't happen. There was no infection. Curious, he investigated, and discovered that quills possess antibiotic properties.

Porcupine quills are coated with fatty acids that give the quills a greasy feel.

Extracts of quill fatty acids strongly inhibited the growth of six bacterial strains.

Roze suggests that porcupines benefit from antibiotic properties because they commonly quill themselves. Although porcupines are good climbers, they seek precarious places because they favor the leaves and buds at the ends of branches and the tops of trees. Roze examined 37 porcupine skeletons and found that one-third had suffered fractures from falls, and he commonly saw falling-related injuries in porcupines he studied. Roze suggests that quill antibiotics may limit self-injury suffered in such falls.

Click here to view this episode in separate page.

A big porcupine waddles along the shoulder of the highway on a September evening, and fortunately a passing driver gives him a wide berth as she drives by. It's the fall mating season for porcupines, and males like this are on the move, looking for receptive females. People see porcupines more often in the fall because a male may expand his home range (of six to 12 acres) as much as five times in mating season. A female is in estrus just once a year, for about 12 hours. That's a narrow window, but males find them using their sense of smell. Females signal with a scent on their bodies and in their urine, and males track them down. If more than one male is interested in the same female, they will fight for the opportunity to mate.

Porcupines have an extremely long pregnancy, about seven months, the longest of any rodent. Moms give birth to just a single baby in the spring, called a porcupette. The quills are not a problem for the mother at birth as the porcupette is encased in a little sack known as a caul. The porcupette's quills are also soft and harden within an hour. The porcupette stays with its mother throughout its first summer, wandering off in the fall by the time she's ready to mate again.

Click here to view this episode in separate page.

The Quill coat

On a fall day in southeast Alaska near Juneau I’m deer hunting, sneaking through the coastal rainforest. I spot a big cavity in the roots under a spruce tree, and there’s fresh dirt thrown out – something has been digging. Is it a bear den? I cautiously approach and peering into the darkness I see what looks like a porcupine. It’s not moving and as I lean closer, I smell it – it’s dead. But it’s also not really a porcupine. I pull it out with a stick and discover that it’s a porcupine skin– all the fur and hair and quills, but the body is gone. It’s very weird.

Doing some research, I learn there’s a name for this. It’s called a quill coat. There’s a predator that is skilled at killing porcupines, and it’s able to completely skin the animal before eating it – leaving the quill coat behind. That animal is a fisher, a large cat-like weasel – bigger than a marten and smaller than a wolverine. Fisher are new in the Juneau area, expanding their range west along the Taku River from British Columbia down to the coast. Fisher attack a porcupine’s vulnerable areas, biting the face and flipping them over to tear into the soft, quill-free underbelly. They’re good climbers and can climb down a tree head-first – all the better to take out a porcupine that’s climbing up.

Click here to view this episode in separate page.

Click here to view this episode in separate page.

Bats and rabies

On a warm Sunday afternoon in June 2022, a woman spots a small dark creature crawling across the lawn of her apartment building in Douglas Alaska. It’s a bat, out in the daytime, which is pretty weird. Sometimes a healthy bat may be disturbed from its daytime roost, or may become disoriented and will be seen in the daytime, but will fly off and find cover. This one just laid there, so she scooped it into a small cardboard box without touching it, and called Fish and Game. A biologist collected the sick bat and sent it to Fairbanks. There, testing by wildlife veterinarian Kimberlee Beckmen revealed the bat was carrying rabies. This is the first time a bat in the Juneau area has tested positive for rabies.

Fish and Game’s Wildlife Health and Disease Surveillance Program tests about a half-dozen bats a year for rabies. In more than 50 years of testing in Alaska close to 200 bats have been examined; in all that time only six bats have tested positive for rabies. All six rabid bats were found in Southeast Alaska, either dead or exhibiting abnormal behavior.

Most rabies in Alaska occurs among arctic and red foxes in northern and western coastal areas. Dogs and other mammals are sometimes infected, and its important that people keep pets vaccinated. In this case, there was no report of any other animals or people being affected.

Click here to view this episode in separate page.

Raccoons

Growing up in Oregon, raccoons were a familiar sight. They lived in the abandoned orchard behind my house, and I'd see them and their distinct tracks down at the slough where I fish. Raccoons aren't native to Alaska, but there have been a number of attempts to introduce them. Raccoons were introduced in the late 1920s or early 1930s by fur farmers to Long Island, near Kodiak. They persisted for a few years but have not been seen for decades and are presumed to be extirpated.

In Southeast Alaska, eight raccoons from Indiana were released on Singa Island near Prince of Wales in the early 1940s. These were Melanistic raccoons, with black fur, and their descendants were reportedly seen into the 1990s. There have been no sightings in recent decades.

In 1950, raccoons of unknown origin were released or escaped on Japonski Island near Sitka. They were seen for years around the garbage dump by the Sitka airport until the early 1970s but haven't been seen since.

Raccoons were introduced to Haida Gwaii in British Columbia and spread to nearby islands where they have seriously impacted colonies of nesting seabirds. These non-native predators could've inflicted similar damage had they become established in Alaska.

Click here to view this episode in separate page.

Rats

It's a quiet late summer night in an Anchorage neighborhood. A truck sits in the driveway of a house, and suddenly there's movement in the shadow. A big rat with a long tail scurries from the shadow of the house, pauses for a moment in the driveway, then scurries under the truck. The scene was captured on a home security video camera, and the footage was provided to Fish and Game via the department's online reporting website - which also provides an email and phone contact to report sightings or rats and other invasive critters. Photos are helpful, and better yet, kill the rat and freeze it, and give it to Fish and game.

Rats are not well-established in Anchorage, and to help keep it that way, it is illegal to keep pet rats in the city. Biologists think the critter in the video was likely a muskrat - and that's a good thing. Muskrats are native to Alaska, and Norway or brown rats are invasive. Norway rats aren't Norwegian, they're from the Asian steppes and as people spread across the globe, rodents tagged along. Rats and mice are responsible for billions of dollars of damage worldwide each year. They eat and contaminate vast quantities of crops, food and livestock feed, chew through communication and electrical lines, and spread a variety of diseases to humans, livestock and wildlife. Fish and Game is working to minimize the spread of rats in Alaska.

Click here to view this episode in separate page.

Red fox gone

A red fox approaches a visitor to Round Island in Bristol Bay. Foxes here are habituated to people and are pretty tame. Red foxes are able to reach Round Island in winter on sea ice, and colonized this island on their own. But foxes were introduced to hundreds of islands in Alaska in the 1920s for fur farming, and they were largely abandoned when the industry collapsed during the depression. Foxes were introduced to about 180 islands in Southeast Alaska, 73 islands in and around Prince William Sound, and 51 islands around Kodiak. None remain. Over time, after the fur farmers quit caring for the foxes, they disappeared. Various reasons contributed: they depleted the available food, they were outcompeted by otters and other native predators, and they were eaten by bears and other predators. While foxes are abundant across most of Alaska and in the Yukon and British Columbia, they don't seem to do well on these coastal islands.

Foxes were introduced to 88 islands in the Aleutian chain, and on many of these islands they thrived after they were abandoned. The difference was nesting seabirds and unfortunately, they devastated vast numbers - entire colonies of island nesting sea birds. Introduced foxes have since been eradicated on dozens of these islands, and large and sometimes spectacular increases in bird numbers have been documented.

Click here to view this episode in separate page.

Click here to view this episode in separate page.

Click here to view this episode in separate page.

Squirrel Midden

On a weekend camping trip, my daughters find a squirrel midden at the base of a big spruce tree. The owner of the midden announces his displeasure at our presence. The midden is a large, fluffy mound of shucked spruce cone scales, many feet deep, left over after the squirrel ate the tiny seeds inside thousands of spruce cones. The pile is interlaced with tunnels, and the squirrel has hundreds of cut cones stashed in the midden, his store of food for the upcoming winter. Squirrels don't hibernate and are active all winter

Alaska's red squirrels are found across the forested areas of the state. They're fiercely territorial, defending a territory about one-acre in size, and will drive off any interloping squirrels, and even birds like Steller jays. They are also curious and opportunistic, and will raid a neighbor's cache if they can.

An acquaintance in Fairbanks snared squirrels at a midden near a house because the homeowner had problems with squirrels getting into his roof and tearing up the insulation. They ended up with 48 squirrels. There were not 48 squirrels initially in that one territory or using that midden, but when one squirrel disappears from its territory, other squirrels from the surrounding area infiltrate in.

Click here to view this episode in separate page.

Squirrel Tracks

Squirrels are rodents, and like all rodents they have four toes on their hand-like front feet and five toes on their hind feet. The hind feet have a distinct heel and offer an important clue for track identification for rodents - the three middle toes of the hind feet are parallel to each other, and noticeably longer than the two side toes. Alaska his home to two tree squirrels, the red squirrel and the northern flying squirrel, and Arctic ground squirrels are the single ground squirrel species.

Squirrels move mostly by bounding - and the hind feet land in front of the front feet. Flying squirrels actually hop; in a hop, the front feet stay in front of the hind feet. Flying squirrels are nocturnal and they're rarely seen, but you may find sign. In winter, you might spot the sitzmark in snow, the impression made by the squirrel's feet and body where it landed. A sitzmark in an open area with tracks leading off is a good indication of a flying squirrel.

A gliding animal like the flying squirrel can be expected to leave intermittent trails, but so does the red squirrel, because its trails are mostly tree to tree. Red squirrels store food in underground caches, and their tracks reveal their routes between holes at the base of trees. They're territorial, so their tracks form a small group of trails as they run repeatedly back and forth between the holes and trees in their home range.

Click here to view this episode in separate page.

Swimming cats

On a cold dark November night, a lynx stands on the banks of the Tanana River south of Fairbanks. The river has not yet frozen, but large plates of ice swirl in the current. The lynx wades into the freezing water and begins swimming across the river.

Researchers with the University of Alaska Fairbanks collared 23 lynx between 2008 and 2012. Knut Kielland and his colleagues are studying lynx movements and learning about habitat, activity patterns, and dispersal. The collars allowed them to precisely track the movements of these northern wild cats.

They were surprised to learn that several of the animals repeatedly swam across the Tanana River in October and November, in freezing weather but before it froze solid. The Tanana is a large, swift, glacial river; it is the largest tributary of the Yukon River and more than a mile wide in places, with braided channels. One male crossed the main channel of the river six times in November. Another male crossed the Tanana 14 times Tanana between September and November, and swam across sloughs and channels of the river (up to 50 meters wide) an additional 20 times. A female lynx swam across the river 11 times and swam across smaller braids, channels and sloughs 40 times in freezing cold weather.

Click here to view this episode in separate page.

Click here to view this episode in separate page.

Bats

A cargo ship approaches the coast of Australia. It's been at sea for weeks, and passed through the Panama Canal. The ship picked up a hitchhiker in Panama. A fruit bat.

Bats sometimes roost in ships in port and may be transported to new areas. Silver-haired bats have been found hibernating in ships and yachts in New York. Little Brown Bats roosted aboard a ship that traveled from Canada to Europe, flying ashore after arrival in the Netherlands. The presence of individual Little Brown Bats in rabies-free Iceland has been attributed to travel by ship.

Bats are also translocated when they get closed inside shipping containers. Free-tailed bats from the tropics have been transported in fruit shipments. A Pallid Bat was discovered in Victoria, British Columbia, in a shipment of lettuce from California.

One concern is that these bats could introduce rabies and other diseases to rabies-free areas. Another concern is the transmission of a bat disease that's killed millions of bats in eastern US in the past decade, white-nose syndrome. It's suspected that a bat sick with the disease discovered in 2016 near Seattle, more than a thousand miles from the nearest known infected bats - could have made it to Washington via a cargo ship.

Scientists with the Alaska Department of Fish and Game are collecting reports of bats found aboard vehicles, in shipping containers, or flying out of containers when they are opened or unloaded. This can help better understand, and hopefully combat, the spread of bat diseases to Alaska and other western states.

Click here to view this episode in separate page.

On a summer day at 3,000' in the open green alpine of Baranof Island in Southeast Alaska, a creamy white mountain goat peers over a cliff. Mountain goats were introduced to Baranof Island in 1923, but those goats are not the ancestors of this big nanny. Her ancestors were here in the ice age.

A hundred years ago, believing there were no goats on Baranof, Alaska's territorial governor authorized a transplant. 18 mountain goats were captured in Tracy Arm, a fjord south of Juneau, and brought about 100 miles west to Baranof and released. Over subsequent decades the population grew, and in 2005 a survey counted 1,500 goats. In recent years, tho, researchers studying mountain goat genetics discovered there are two, different lineages on Baranof- one a carbon copy of those Tracy Arm mtn goats - and another that's unique to Baranof Island.

During the ice age, parts of Southeast Alaska, including parts of Baranof Island, were ice free and served as refugia for many different animals. It turns out that mountain g oats had been living in the remote mountains of Baranof for thousands of years when the new goats were introduced.

Click here to view this episode in separate page.

White-nose Bat

On a calm night in early April, 2016, a biologist is checking a bat detector near Juneau. The device hears and records the high-frequency calls bats make, and there are a lot of bats out this night. These are little brown bats, the most common and widespread bat in Alaska. They've been active for weeks, and emerged from hibernation in Southeast Alaska almost a month early this year.

Populations of little brown bats in the Eastern U.S. have been decimated over the past decade by a disease called white-nose syndrome, a fungus that grows on bats during the winter while they are hibernating. In some areas, 99 to 100 percent of the little brown bats have died, and biologists estimate more than six million bats in the east and Midwest have died from this disease.

In mid-march of 2016, a sick bat was found on a trail by a hiker in the forest about 30 miles east of Seattle. The bat died a few days later and tested positive for White Nose syndrome. This is the first case of the disease west of the Rockies; in fact, it's 1,300 miles west of the nearest cases in Minnesota and Eastern Nebraska. How this western bat acquired an eastern disease is unknown, and bat researchers are working hard to learn how and why the disease showed up in Western Washington, and if any other bats are carrying it.

Click here to view this episode in separate page.

Who hibernates?

Hoary marmots are just one of seven mammals in Alaska that curl up in dens or burrows and sleep through Alaska's cold, dark season. The other mammalian hibernators are Alaska marmots, woodchucks, black bears, brown bears, arctic ground squirrels and brown bats.

Hibernation is not the same for all animals. Arctic ground squirrels are the deepest sleepers and survive in a catatonic state by dropping their metabolism and core body temperatures to 27 degrees Fahrenheit, the lowest known body temperature for a hibernating mammal.

While arctic ground squirrels hibernate alone, Alaska's marmot species hibernate in family groups or small colonies in burrows under rock piles or boulder fields. They insulate their rocky burrows with dry foliage and plug the entrance before they settle in for a six or seven month sleep.

The little brown bat, which is just about half the size of a chickadee, is the tiniest hibernating mammal in Alaska. Bats hibernate in groups, in protected roosts called hibernaculum, which may be inside tree cavities, abandoned buildings or caves. It is believed that bats in Interior Alaska migrate to moister, warmer parts of the state to hibernate.

Bears are the lightest sleepers, and will wake up occasionally and move around inside the den, shifting their sleeping position. Bears also shift positions to better conserve heat and to prevent pressure sores from developing. Waking a hibernating arctic ground squirrel can take hours or days. Bears, on the other hand, can rouse quickly when disturbed.

Click here to view this episode in separate page.

Wolverines

It's chicken day at the Alaska zoo, and the wolverines are excited. One wolverine isn't happy when another starts watching her eat, and hisses like an angry cat. But he's got his own chicken and he's not interested in taking her bird away. Fish and Game researchers Howard Golden and Mike Harrington are studying wolverines, and said despite their reputation as antisocial loners, wolverines can be pretty tolerant of each other if there's no competition for food. They've seen wolverines in the wild playing, and watched them long enough to see they're socializing, not fighting.

Wolverines are scavengers. They've got a really good nose, they can smell food over long distances or buried deep under the snow. But they're also very opportunistic and kill small game. Ground squirrels and marmots are important prey items, as are snowshoe hares and voles. In coastal areas wolverines eat the eggs of ground nesting birds like oystercatchers and gulls.

Wolverines are very strong for their size and have incredible stamina. Golden and Harrington tracked 15 wolverines and said a wolverine can cover 30 miles in a night in search of food, although about eight miles a day was average for females and a bit more for males, up to about 12 miles a day. They are excellent climbers and traverse incredibly rugged mountainous terrain, quickly climbing steep, icy slopes.

Click here to view this episode in separate page.