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Download Episode: Bison Foray (MP3 file 1,411 kB)

Bison Foray

A giant brown wood bison stands in a vast green meadow near Galena in Interior Alaska. He's almost as big as an SUV, a hulking bull approaching the prime of his life. He's called bull 161, sometimes known as the Galena Bull because he hung around Galena in 2017.

Bull 161 is a traveler. He was born at the Alaska Wildlife Conservation Center in 2011, and in 2015, when he was four years old he was one of 130 wood bison released to the wild near Shageluk, on the Innoko River. He stayed there near the main wood bison herd for the first year, and in early summer of 2016 he moved about 50 miles south to the Holy Cross area on the lower Yukon. In January 2017 he was near Galena, 180 miles north!

Young adult bull bison often go on forays. If they find a location with good habitat, they may spend a year gaining weight, and return to the herd as a larger, stronger, more successful competitor during the breeding season. Bull forays are also a way that bison herds expand their range. Once a bull returns from a foray he may collect a group of cows and bring them back to the newly discovered habitats.

One large bull has done that. He spent almost a year alone near the mouth of the Iditarod River, then in fall of 2016 he returned to the core bison area near Shageluk, joined a group of 10 animals, and in 2017, they followed him back to the Iditarod. After almost a year, that group has grown to 24 bison, including 5 new calves.

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Download Episode: Farewell Bison (MP3 file 1,407 kB)

Farewell Bison

When wildlife biologist Roger Seavoy flew an hour south of McGrath in the spring of 2014 to survey bison, he found more than he'd seen in years - more than 400 animals. That's good news for a herd that declined considerably a decade ago.

The Farewell herd is one of four herds of plains bison in Alaska. The herd inhabits the Farewell area of the drainages flowing into the Kuskokwim River, about 200 miles west of Anchorage. Plains bison are an exotic species - they were introduced to Alaska in 1928 - and herds exist near Delta Junction, and near the Copper and Chitina rivers. in the mid-1960s, 38 bison from the thriving Delta herd were released to establish the Farewell herd.

By the late 1990s the Farewell herd numbered about 350 animals. Then around 2000, bison numbers started dropping. Hunter harvest and especially decline in habitat quality were big factors. Hunting was curtailed and numbers started increasing, but the biggest help was a fire.

A wildland fire in the spring of 2010 spread out into the bison range and burned several thousand acres, revitalizing the plant community. Bison, and moose, thrive on the forage that grows abundantly after a fire. With nutritious forage available, bison numbers increased quickly.

Seavoy has about 30 bison equipped with radiocollars, which helps him locate the members of the Farewell herd. In his last spring survey he counted 319 adults and 85 calves.

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Download Episode: More Wood Bison (MP3 file 1,407 kB)

More wood bison

In late May, 2015, a one-ton wood bison bull is loaded into a shipping container at the Alaska Wildlife Conservation Center in Portage. A month earlier, about 100 wood bison cows and calves were flown in a giant transport plane to Shageluk, and then released into the wild near the confluence of the Yukon and Innoko Rivers. Like muskox, wood bison are native to Alaska and were extirpated in the 1800s. The wood bison release is the culmination of a 20-year effort to reintroduce the animals to their native range. Wood bison are giant cousins to the more familiar plains bison, and are the largest land animal in North America.

Rather than fly the massive males to the wild, Fish and Game elected to send them by boat. Breeding season for wood bison is in July, and biologists knew the big males could arrive after the initial introduction established the herd. A dozen bulls were trucked up the Seward and Parks Highways to Nenana, where they were loaded on a barge for the four day trip down the Tanana River to the Yukon, where they could reunite with the herd. Each bull was kept in his own air-conditioned container to insure they would not overheat on the trip. Biologists plan to barge 16 more bulls to the release site later in the summer of 2015.

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Download Episode: One-Ton Bison (MP3 file 3,817 kB)

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Download Episode: Plains Bison 2017 (MP3 file 1,407 kB)

Plains Bison in Alaska

On a cold October day, a bison hunter is crossing an open field of brown stubble near Delta Junction in Interior Alaska. He's alert, and he's focused on a line of trees ahead. He doesn't realize it, but a group of two dozen plains bison is quietly crossing the field behind him. He catches sight of them as they drop over an embankment, but it's too late to take a shot. He told me later how impressed he was with how quiet and elusive those huge animals proved to be.

Plains bison were introduced to Alaska in 1928, when 23 animals from Montana were brought to Delta Junction. Three died within a few months, so all of the plains bison in Alaska today are descendants of 20 animals. As the herd in The Delta Junction area grew, a few dozen animals were released into other areas of Alaska, establishing a total of four herds of plains bison totaling about 1,000 animals in 2017

The Delta herd in the central Tanana Valley near Delta Junction has about 360 bison. The Chitina River herd inhabits the area around the Chitina River from the confluence of the Tana River and the Chitina Glacier. It's the smallest herd with about 50 animals.

The Copper River Herd, about 100 miles east of the Chitina, near the Alaska/Canada border is slightly larger, with about 60 animals.

The largest plains bison herd in Alaska is the Farewell herd. The Farewell herd inhabits the Farewell area of the drainages flowing into the Kuskokwim River south of McGrath. It's been growing steadily for the past decade, and the most recent survey in 2017 counted 500 animals.

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Download Episode: Swimming Bison (MP3 file 1,413 kB)

Swimming bison

In the summer of 2015, wildlife biologist Tom Seaton was flying over wet sedge meadows in interior Alaska checking on the newly introduced wood bison. As he flew over the Innoko River, he saw eight bison of the Lower Yukon/Innoko Rivers Herd swimming across the river - seven big adults and one rusty red calf. Numerous sets of tracks leading into and out of the water up and down the muddy river bank showed that bison had crossed the Innoko many times.

We don't think of bison as swimmers. Plains bison are stocky, muscular beasts, and wood bison are even bigger, with muscular shoulders and a massive shoulder hump. Plains bison and wood bison both evolved from a common ancestor, the now extinct steppe bison. Plains bison evolved in open country further south, while wood bison developed attributes better suited to the north - a heavier coat and the massive shoulders that enable them to plow through deep snow. In summer, they range across a landscape of meadows around lakes and rivers, and they are capable swimmers.

Although bison of the Lower Yukon/Innoko Rivers Herd frequently cross the Innoko River two animals are even more ambitious and aquatic. Satellite tracking shows that these two bison have explored habitat along the Yukon River between Russian Mission and Galena, swimming across the nearly mile-wide Yukon River several times.

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Download Episode: White Bison Calf (MP3 file 1,408 kB)

White bison

A super cub airplane is flying over the lush green expanse of Interior Alaska, about 60 miles south of McGrath. Wildlife biologist Josh Peirce is conducting the spring 2017 survey of the Farewell Bison herd, and he spots a very unusual looking calf. It's white. The three-month old calf is mixed in other normal-looking, cinnamon red-colored calves of the year, and the big dark brown adult bison.

The white calf was born into the Farewell Bison Herd, one of four herds of plains bison in Alaska. Plains bison, smaller cousins to the giant wood bison, were introduced to Alaska in 1928 when animals from The National Bison Range in Montana were brought to Delta Junction. All of the bison in Alaska's four herds are the descendants of 20 animals. The farewell herd has about 500 bison.

White bison are well documented, but they are very rare. There are about 1,000 bison in Alaska in those four herds, and this is the only white animal known in Alaska.

In bison country in the Lower 48, tourism and marketing outfits will tout statistics on the occurrence of white bison that are not reliable. "One in a million, or one in ten million, but there aren't a million bison in North America."

There are about 380,000 plains bison in North America, in private herds, and in public herds in state, county and national parks. As of 2017, there are about two dozen white bison known in North America, counting the new calf in the Farewell herd.

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Download Episode: Wood Bison 2016 (MP3 file 1,406 kB)

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Download Episode: Wood Bison 2018 (MP3 file 1,409 kB)

Wood Bison 2018

In June of 2018, fifty dark brown wood bison are grouped together in a green sedge meadow near the lower Yukon River. Six cinnamon colored calves of the year are mixed in with the adults. It was a hard winter for these wood bison, and they're just now gaining back weight they lost over the winter.

Alaska's only wild wood bison herd had significant losses in spring of 2018, decreasing from about 140 animals in June of 2017 to a count of 90 animals in June of 2018.

Those 140 wood bison were in excellent body condition in the fall of 2017. But in late February 2018 it started to snow and sometimes rain at least once a week. This deep, firm snow made it hard for bison to move and find food under the snow. Wolves were another factor. Wolves had a major advantage during March and April because they could run on top of the snow and bison and moose had a very difficult time moving. As the weeks went by, the wolves got stronger from eating so well and the herbivores got weaker from the increased harassment by wolves and the lack of access to forage.

About fifty bison succumbed to starvation and predation in the difficult spring of 2018. But the remaining 90 wood bison rebounded fast when the vegetation greened up in May. These hardy survivors are the bison that can handle a difficult winter event. By mid-June bison were fattening up, and 11 new born calves were counted in June of 2018

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Download Episode: Wood Bison 2021 (MP3 file 2,337 kB)

An orange airplane flies over the broad green expanse of Southwest Alaska near the Lower Yukon River in late June of 2021. The plane is the Fish and Game de Havilland Beaver, equipped with an ultra-high-definition digital camera for aerial photocensus surveys. These surveys are most often conducted on Alaska's caribou herds, but this June, Alaska's four herds of plains bison have been surveyed. Today, it's photographing Alaska's wood bison, in the Lower Innoko-Yukon Rivers herd, near Shageluk. The photographs enable biologists to count individual bison, and identify the smaller, reddish brown calves.

Calving is at an all-time high, with 26 calves born in the spring of 2021. Overall, the herd has grown by more than 10% in the last year, to a total of 103 bison. Since the release of the wood bison herd in 2015, it has grown in four out of six years. The two years of decline were likely due to ice layers forming in the snowpack from winter rainstorms and warming events.

Bison are good at foraging in deep, soft snow, but ice layers in the snowpack make this more difficult. In late winter of 2021, there was deep snow, but no ice layers. With any luck, there will not be rain-on-snow events in coming years and this herd will have a chance to grow even more.

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Download Episode: Wood Bison Reintroduction (MP3 file 1,411 kB)

Wood Bison Reintroduction

In late May, 2015, a one-ton wood bison bull is loaded into a shipping container at the Alaska Wildlife Conservation Center in Portage. A month earlier, about 100 wood bison cows and calves were flown in a giant transport plane to Shageluk, and then released into the wild near the confluence of the Yukon and Innoko Rivers. Like muskox, wood bison are native to Alaska and were extirpated in the 1800s. The wood bison release is the culmination of a 20-year effort to reintroduce the animals to their native range. Wood bison are giant cousins to the more familiar plains bison, and are the largest land animal in North America.

Rather than fly the massive males to the wild, Fish and Game elected to send them by boat. Breeding season for wood bison is in July, and biologists knew the big males could arrive after the initial introduction established the herd. A dozen bulls were trucked up the Seward and Parks Highways to Nenana, where they were loaded on a barge for the four day trip down the Tanana River to the Yukon, where they could reunite with the herd. Each bull was kept in his own air-conditioned container to insure they would not overheat on the trip. Biologists plan to barge 16 more bulls to the release site later in the summer of 2015.

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