Sounds Wild
e-Library Multimedia

Click here to view this episode in separate page.

Click here to view this episode in separate page.

Crèche

On a midsummer day a flock of 40 mergansers swims along the edge of a saltchuck, an intertidal pond. They favor the shallows and the margins of the waterweeds - there are hungry eagles watching and the vegetation provides an escape to cover. This is no ordinary flock; it's comprised almost entirely of young of the year, big merganser ducklings banded together in a crèche. There are a few adult females mixed in, but there are too many ducklings for these to be their babies. The adults are essentially babysitters.

A variety of birds will form crèches, aggregations of young watched over by a few adults. Some penguins do this, Canada geese, and some terns. Flamingos also do this, and parents will return to the crèche to feed their young. It was once thought that adults indiscriminately fed the young, but observations showed adult flamingos find and feed their own young. Terns also recognize their own young by their voices and calls.

Birds aren't the only animals to form crèches. Spectacled caiman, a South American crocodile, raise their young in crèches, one female taking care of her own as well as other mother's offspring. Lions also form crèches, and females within a pride will provide mutual protection and even nurse each others' cubs.

Merganser chicks, like other ducklings, are precocial and don't need a lot of care - they hatch out capable of swimming and feeding themselves. A few adults keep watch for predators and help keep the crèche together. In a few months, these young ducks will be adult size and ready for their first winter.

Click here to view this episode in separate page.

Ducks aplenty

Fall in Alaska, and ducks and geese are on the move. About 20 percent of all North American waterfowl - at least 34 different species - spend the summer nesting season in Alaska. Seven million ducks summer in Alaska, including half of North America's pintails, and 80 percent of the world population of Pacific black brant. More than a million geese spend the summer nesting season in Alaska.

Alaska supports the entire U.S. breeding populations of several species of seaducks including spectacled, king, and Steller's eiders; as well as long-tailed ducks; and all three species of scoters - black, white-winged, and surf scoters, and many of these also winter in coastal Alaska. 20,000 trumpeter swans, 70,000 sandhill cranes, and 120,000 tundra swans and summer in Alaska.

Because waterfowl migrate across state and international boundaries, the Alaska Department of Fish and Game's Waterfowl Program collaborates with other state and federal agencies, in particular the U.S. Fish and Wildlife Service, in management of waterfowl.

Alaska's waterfowl biologists have studied scoters, sandhill cranes, dusky Canada geese, harlequin ducks and Steller's eiders. Biologists are continuing to monitor the recovery of harlequin ducks in Prince William Sound following the Exxon Valdez oil spill. And banding projects are helping biologist monitor birds and better understand the different populations and the distribution of migratory waterfowl throughout the Pacific flyway.

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.

Emperor geese

On a blustery gray fall day, a flock of geese sets down in a protected cove on the west side of Kodiak Island. These are emperor geese. The emperor goose is an Alaska bird - virtually the entire world population is found only in Alaska.

Some geese migrate thousands of miles between their summer nesting areas and their winter refuges. The dusky Canada goose nests on Alaska's Copper River Delta and winters in Oregon's Willamette Valley. But most emperor geese winter and summer in Alaska. While a small number do nest across the Bering sea in the Russian far east, ninety percent of the geese breed on the Yukon-Kuskokwim Delta. Most of the remaining ten percent nest on the Seward Peninsula. In the fall these emperor geese move south a few hundred miles and winter in the Aleutian islands and along the Alaska Peninsula to the coast of Kodiak Island.

Since 1981, biologists have flown annual spring surveys in to estimate goose numbers. In the 1980s, the population declined from more than 100,000 birds in 1982 to fewer than 45,000 in 1986. Hunting was closed, and over the following decades numbers gradually increased. The most recent count was almost 86,000 birds and in 2017, and after a 30-year closure, a limited hunt was reinstated, allowing an Alaska hunter to take just one Emperor goose during the fall hunting season. With careful management, Alaska's unique population of emperor geese will continue to grow.

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.

Kingfisher eyes

A kingfisher is perched on a branch over the water, watching a school of salmon fry. When the moment is right, she dives, plunging under the water and emerging with a wriggling fish.

It's quite a feat for a kingfisher to catch a fish underwater because from the air, the fish isn't where it appears to be. Water bends light rays more than air does and viewed from the surface, the fish is actually a few inches away from where it seems to be. Kingfishers solve this with a special feature in their eyes that we don't have. In the back of a human eye, on the retina, is a little pit called the fovea with a lot of visual cells that create an area of very acute vision. The kingfisher has not one but two foveas, separated by a little distance, and their vision shifts smoothly from one to the other as they enter the water. When the kingfisher dives into the water, the second fovea is engaged, and that gives the diving bird high visual acuity at the all-important last moment before it grabs its prey with its bill.

A South American fish called anableps has a similar, but opposite arrangement in its eyes. The fish swims at the water surface and can see above and below the water at the same time. The upper half of its eye is adapted for seeing in the air and the lower half of the eye is adapted for seeing under water.

Click here to view this episode in separate page.

Kittiwakes

Above a small rocky island in Glacier Bay, hundreds of grey and white seagulls wheel and dive. They're black-legged kittiwakes and this is a summer nesting colony. Nesting is one of the only times kittiwakes come to land. A true gull of the sea, kittiwakes spend most of their lives away from land. They don't need freshwater and drink only seawater. Like many ocean-going birds, kittiwakes have a special gland that desalinates their blood and secretes an extremely salty fluid into their nasal cavities, which then drips from their nostrils.

There are two kinds of kittiwakes, black-legged and red-legged kittiwakes. Red-legged kittiwakes are uncommon, they're mainly found in the Gulf of Alaska and more than 90 percent of Alaska's red legged kittiwakes nest on the Pribilof Islands in the Bering Sea. These birds were profoundly impacted by the introduction of rats to the Pribilofs, which eat eggs and birds.

Black-legged kittiwakes are far more common and favor Arctic and subarctic waters across Western and eastern North America, as well as Scandinavia and eastern Siberia. Kittiwakes are the only cliff nesting gull, and they can nest on nearly vertical cliffs, laying one or two eggs in a small nest made of seaweed or moss. Some winter entirely at sea, others travel down the east and west coasts. In coastal New England states, Kittiwakes are also known as frost gulls, where their arrival in the autumn coincides with the first frosts. Their more common name, kittiwake, comes from the sound of their calls.

Click here to view this episode in separate page.

Loons

Camping on a lake in late summer, we hear a loon calling. A loon calling at night is often answered by its mate, but this one is calling solo. Loons are water birds, only going ashore to mate and incubate eggs. Their legs are placed far back on their bodies, excellent for swimming but awkward for walking.

Loons are well equipped for their submarine maneuvers to catch fish. Unlike most birds, loons have solid bones that make them less buoyant and better at diving. They can quickly blow air out of their lungs and flatten their feathers to expel air within their plumage, so they can dive quickly and swim fast underwater. A loon shoots through the water like a torpedo, propelled by powerful thrusts of those strategically placed feet. When their quarry changes direction, loons can execute an abrupt flip-turn: they extend one foot laterally as a pivot brake and kick with the opposite foot to turn 180 degrees in a fraction of a second. Loons sometimes work together to chase schools of fish.

Loons are agile swimmers, and they move pretty fast in the air, too. Migrating loons have been clocked flying at speeds more than 70 mph. But because they're heavy, they need a lot of water to take off, and will run across the top of the water for sometimes hundreds of yards, flapping hard, to get enough speed to get airborne.

Click here to view this episode in separate page.

Murrelet Triangle

Marbled murrelets are listed as endangered and threatened over most of their former range along the Pacific Coast from California north to British Columbia. They spend most of their lives at sea, and are very secretive nesters when ashore. Although this is a very elusive bird for people to see down South, it is by far the most abundant seabird in Southeast Alaska, home to the world's greatest concentration of murrelets.

For a number of years Biologist Matt Kirchhoff worked with marbled murrelets in the waters just south of Juneau, in Stephens Passage, Tracy Arm and Port Snettisham. He saw thousands of birds, and on the basis of those surveys, Port Snettisham has been designated a globally Important Bird Area by Bird Life International and Audubon.

However, in recent years, Kirchhoff and his colleagues have found an even higher concentration of birds in and near Glacier Bay - the "murrelet triangle." During the summer, tens of thousands of marbled murrelets nesting in surrounding forests congregate in the area to forage for fish and krill. Murrelet surveyors have counted as many as 5,000 murrelets an hour flying into this area during morning feeding migrations.

The area is bounded by Sitakaday Narrows in Glacier Bay, Point Adolphus on North Chichagof Island, and Lemesurier Island in Icy Strait. The upwelling of cold, nutrient-rich water brings feed, drawing humpback whales, murrelets, sea lions and other predators.

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.

Pigeon Guillemot

Pigeon guillemots are among the most common seabirds in the west, and among the most abundant diving seabirds in Southeast Alaska. They are found from the Bering seacoast in Northern Alaska along the Pacific coastline to Southern California.

Pigeon guillemots are black birds with a distinctive white bar on each wing and bright red legs and feet. In winter, their plumage becomes more mottled, but the white wing bars still stand out. They nest in loose colonies, often above rocky shores.

They are alcids, members of a family of diving birds that includes murres, murrelets, auklets and puffins. Alcids "fly" underwater, swimming with their wings rather than their legs. Guillemots are about a foot long, slightly larger than murrelets. Like murrelets, they sometimes have difficulty taking off, so to escape danger, they are more likely to dive and swim than to take off and fly.

Pigeon guillemots forage closer to shore than other Southeast alcids. There's a good reason for that: Unlike murrelets, which generally forage in the water column and feed on schooling fish such as herring, guillemots usually dive to the seafloor and hunt for fish along the bottom. Blennies, small, eel-like fish, are a favorite food. Guillemots also eat mollusks, crustaceans and marine worms.

One special adaptation for this sea floor foraging is the pigeon guillemots' blood, which is rich in hemoglobin and has the capacity to hold more oxygen than the blood of most seabirds, and to metabolize that oxygen faster.

Click here to view this episode in separate page.

Click here to view this episode in separate page.

Scoters

Scoters are big black sea ducks, fairly common in coastal Alaska. They congregate in large flocks in the spring, sometimes numbering thousands of birds, before they migrate to freshwater marshes in interior and northern Alaska and Canada to nest.

Scoters' wings make a whistling sound as they fly. These big ducks don't leap into flight like mallards, they need some "runway" space on the water to get going, and their wings slap against the surface as they gain the speed to get fully airborne. Once aloft they are powerful fliers and cover hundreds of miles in just a few days during migration.

Scoters feed on mussels and other shellfish, including small crabs. The scoter's gizzard is like a powerful fist that crushes mussels and grinds up the shells. This organ can crush a clamshell that would require a hammer for us to break open. Scoters in a flock dive in sequence like falling dominoes. Within a few seconds, as if cued by some secret signal, dozens or even hundreds of ducks plunge beneath the water. In a large flock, one edge dives first, and row after row of ducks disappears. About 20 or 30 seconds later, they pop up, and in the course of five or 10 seconds the entire flock reappears.

There are three kinds of scoters - surf scoters, white winged scoters and black scoters. All are similar at a glance - large black ducks generally in big flocks. Those flocks may contain a mix of the three species.

Scoters are commonly called coots on the East Coast, and surf scoters are known as skunk-head coots because of the black and white markings (These are not to be confused with the "real" coot, a duck-like bird in the rail family). Back east, white-winged scoters form winter flocks numbering tens of thousands of birds; a raft of 180,000 scoters was counted off Long Island, New York, on a December day in 1952.

Click here to view this episode in separate page.

Seabird colonies: Nesting Niches

On a windy summer day at south Marble Island in Glacier Bay, thousands of seabirds cling to the rocks, hundreds more wheel overhead, and even more swim in the choppy water. The rocky, barren island is a well-known seabird nesting colony, and in late June, gulls, cormorants, pigeon guillemots, kittiwakes, puffins and murres are abundant.

95% of seabirds are colonial nesters, and seabird colonies offer outstanding wildlife viewing. Many seabirds show remarkable loyalty to specific colonies and exact nesting spots, returning to the same site year after year, and they will aggressively defend that site from rivals. This increases breeding success, provides a place for returning mates to reunite, and eliminates the need to prospect for a new site. Young adults breeding for the first time usually return to the colony of their birth, and often nest very close to where they hatched.

On one hand, all these nesting birds are after the same things - protection from nest predators like eagles, ravens, and otters, and access to food for themselves, their mates, and their young. But different species have different nesting needs. Puffins dig tunnels and nest underground. A female mmurre lays a single egg on a narrow rock ledge. The pointed egg, shaped like a top, rolls in a tight circle should it become dislodged. Pigeon guillemots lay two eggs and typically nest in crevices and tiny caves in the rocks. Glaucous-winged gulls generally nest in concentrated colonies, in close proximity to one another with nests commonly hidden in ryegrass or built on bedrock.

Click here to view this episode in separate page.

Click here to view this episode in separate page.

Trumpeter Swans

As spring comes to the north and the ice goes out on lakes and rivers, a giant white bird can be seen winging into Interior Alaska - the trumpeter swan.

Weighing as much as 25 pounds, the trumpeter swan is the heaviest wild bird in North America and the biggest swan on earth. Heading north in the spring on wings that can span eight-feet, these snow white giants fly in goose-like Vee-formation, stopping to rest and feed on emerging aquatic vegetation. Geese, ducks and tundra swans often accompany the trumpeter swans at these stopovers, benefitting from the vigilant trumpeter's keen eyesight.

Trumpeter swans are dabblers and feed in water like mallard ducks, head down and feet up, tearing aquatic plants from the bottom. They also use their webbed feet to dig up bank-side roots and tubers.

Trumpeters were on the brink of extinction in the early 20th century, due to unrestricted market hunting, egg collecting and the lucrative international feather trade. The discovery of a population around Alaska's Copper River in the 1950s provided a source for reintroductions, and the trumpeter has made a remarkable comeback.

Alaska is the summer home to most of the world's trumpeter swans. They build their nests on beaver lodges and mounds of vegetation in shallow freshwater marshes and lakes. Pairs form long term bonds and will return to the same nest year after year to lay eggs and raise their young.

Click here to view this episode in separate page.

Click here to view this episode in separate page.