Chapter 8: Grizzlies in Central and North Alaska

Grizzlies, Eskimos, and Biologists: Cross-cultural Bear Management in Southwest Alaska. By Lawrence J. Van Daele, Alaska Department of Fish and Game, Dillingham, Alaska and co-workers, in Ursus 12:141.152:

Study Area

“The study area was in the southwest Kuskokwim Mountains, midway between Dillingham and Bethel, Alaska. In encompassed 2,850 km² of public lands, including parts of Togiak National Wildlife Refuge, Yukon Delta National Wildlife Refuge, and Alaska State lands.

The mountains intercepted moist winds blown inland from the Bering Sea, and low clouds and fog often covered the area. Mean annual precipitation was 89 cm, including 177.5 cm of snow. Snow persisted in lower elevations from late October to May, and vegetation developed rapidly during the short growing season. Mean maximum and minimum temperatures for January were -10.5°C, and for July were 18.5°C and 7°C, respectively.

Mountainous portions of the area were sparsely vegetated with low growing shrubs and herbaceous plants. Mid-slope areas (300-600 m) were covered with dwarf shrubs, including Labrador tea, crowberry, and sedges, interspersed with dense stands of willow and mountain alder. Lowland areas (150-300 m) were dominated by bog willow (S. arctica) and dwarf birch (Betula nana) as well as various species of berry-producing shrubs including lowbush blueberry, cranberries and bearberry. Cottonwoods dominated the overstory in riparian areas, with willows and Kenai birch in the under story.” Lawrence J. Van Daele et al. (2001:141, 142)

The Kilbuck caribou (Rangifer tarandus) herd (~5,000 animals) was resident to the study area, and in recent years the area was used by a portion of the Mulchatna caribou herd (~200,000 animals). Moose (Alces alces) relatively new to the area, occurred in low densities along riparian corridors.” Lawrence J. Van Daele et al. (2001:142)

Brown bear study area in the south-western Kuskokwim Mountains, Alaska, 1993-97, at the Bering Sea. From: Lawrence J. Van Daele et al. (2001:142) Fig. 1.

Research Results

We captured and marked 60 bears (21 males, 39 females)

Size of adult (<5.5 yrs old) brown bears captured in the southwestern Kuskokwim Mountains, Alaska, 1993-97. Table 2.

Adult males, mean body weight 235.9 kg, range 158.8-299.4 kg.

Adult females, mean body weight 133.0 kg, range 99.8-200.0 kg.

Lawrence J. Van Daele et al. (2001:147)

Home Range and Habitat

“The mean home range for adult females in the study area was 398.1 km².

We located 87 dens for 30 bears. Mean den elevation was 632 m (range 336-1,220). Most dens were in steep, rocky areas (71%), while 13% were in tundra habitats. Most individual bears used the same denning area in consecutive years. Den entrance began in early October and continued through November. Emergence began in late April, and all bears were out of their dens by the end of May.” (2001:147)

“By early July, most collared bears moved to mid and lower elevations (150-600 m) where they were observed eating emergent herbaceous vegetation, squirrels, ptarmigan and caribou. Bears rested in alder and willow thickets when the extended daylight hours resulted in higher ambient temperatures. This pattern persisted until late July when spawning Chinook salmon arrived in the study area and some bears moved to rivers and spawning streams. There were no concentrated feeding areas in the study area where large numbers of bears congregated; rather, they were spread along riparian areas. This distribution pattern persisted through August.

By early September hard frosts had yellowed most herbaceous vegetation and many shrubs and trees had lost their leaves. Bears began to devote most of their waking hours to feeding on various species of berries. As the month progressed, observations during tracking flights suggested that the bears expanded their foraging activities to include all available food sources. Denning activity (movement to denning areas and digging) commenced by late September, and most were in their dens by late October.” (2001:148)

“The study area was beyond the tree line and typical of much of western Alaska. There was a short growing season and limited resources, yet there were significant runs of various salmon species. Bears within the area exhibited characteristics (colour, size, and behaviour) that suggested the population was a mixing area for coastal brown bears and interior grizzly bears.

The bear population occupying the southwest portion of the Kuskokwim Mountains is at least as dense as other bear populations in interior and north-western Alaska. Female home ranges are much larger than those noted on Kodiak Island, but are comparable to other interior Alaska brown bear populations, suggesting habitat similarities (Table 3).” (2001:150)

From: Lawrence J. Van Daele, Alaska Department of Fish and Game, Dillingham, Alaska and co-workers, in Ursus 12 (2001:148). The female home range at Terror Lake, Kodiak Island is 28 km². The female home range at the Noatak River, Northwest Alaska, is 993 km². That is 35.5 times larger. The density at the Noatak River, Northwest Alaska, is 13.9 / 1,000 km². At Terror Lake, Kodiak Island it is 233.8 / 1,000 km². That is 16.8 times less than on Kodiak Island. The Noatak River lies north of Kotzebue and south of the foothills of the Brooks Range. It flows into the Chukchi See..

Brown bears of Alaska

On 13. 1. 2003 the Second Channel of German Television showed at 16:15 o'clock the documentary film, Nomads of the North by Andreas Kieling:

"Alaskan coastal mountains: 2 brown bears at the water-fall. The salmon there swim up the rivers from May to September. Salmon form there by far their most important source of food.

A young grizzly in the forest tundra of North Alaska with musk-oxen.

Tundra grizzlies must eat now much, to put on enough fat for the winter. Already in summer, they ate mostly plants. Day after day they eat now the sweet blue berries. That is their main source, so that they will be able to survive their seven months long winter-sleep. A tundra grizzly eats sweet blue berries. The grizzlies will go now to their caves. There the snow will cover them for the next half year." – Andreas Kieling (2003)

At 01. 01. 2004 the ARD television station at 19:10 o'clock showed the documentary film Denali National Park by Guenter Goldmann and Phil Golas. At Mount McKinley, North America’s highest mountain.

"At the beginning of April: The snow melts. A female grizzly bear with 2 cubs. During the last winter they slept in their den (cave). Now they look for fodder. They are still in their thick winter pelt. The food of the grizzly in the Denali National Park, in the south of Alaska, but north the Coast Range, consists up to 80% of plants. But they do digest the plants only poorly, as their excrements shows.

The wolves and bears there kill 9 of 10 of the newly born moose calves. The timber wolf weighs there 80 kg. The grizzly bear weighs there at least as much as 4 wolves, about 320 kg.

A grizzly in late autumn in its summer-pelt, when the blue berries are ripe and sweet. It eats now blue berries. Thus they are able to up on here a large fat reserve for the long winter, because the blue berries contain now much sugar." – Guenter Goldmann and Phil Golas (2004).

At the 12.^. 3. 2002 the television station WDR showed at 20:15 o'clock the documentary film, Grizzlies, giant bears in North America by Jeff Turner, Canadian animal film maker:

"In the northern tundra of Alaska. Tundra grizzly in Alaska. In a sprint it can reach 50 km/hour.

Grizzly in tundra with cotton-grass near a caribou herd. 

Grizzly and wolves at the carcass of a moose (European elk).

Most Grizzlies do spend the largest part of the day eating plants. Fresh sedge (reed) is their main food.

A grizzly bear at Canada’s west coast is eating grass. It is tender and easily digestible. It contains also protein, but less than meat. Therefore it is not so nutritious. Therefore the bear must eat much more in order to become full.

A grizzly in the mountain tundra. In the autumn, when the berries are ripe. It may eat many berries. In one day it may eat up to 100.000 berries.

Bear in mountain tundra.

At the coast it is easier for the grizzlies to find enough food. Here they dig out shell-fish.

At low-tide they walk over the mud-flat and search for the shell-fish, which are hidden in the mud.

A coastal female brown bear with cubs digs out shell-fishes. The cub will remain three years with its mother. It learns from her, how to survive.

Coastal female brown bear with two cubs catches a salmon. At such a bottleneck, at the water-fall in the creek (brook), the bear devours enormous amounts of fish, without overexerting itself.

When the brown bear catches salmon, it puts on each day a fat-reserve of 5 pounds (2.5 kg).

When they catch many salmon, they will eat only their most nourishing parts, mainly the eggs, the roe (spawn, caviar).

For the coastal female bear the salmon migration is the most important time of the year, in which she is able to store enough fat reserves.

Everywhere at the coast of Alaska the brown bears search for salmon, at the seawater, where the salmon leave the ocean.

On Kodiak Island: A female bear in a lake dives 6 m deep, to pick up the dead salmon, which lie at the bottom of the lake.

Coastal brown bear at the Brooks Falls at the coast of Alaska. They catch the salmon, while these jump up the water-fall, so that they will be able to swim to their spawning places." Jeff Turner (2002)

Yukon Territory

How large and how heavy is the brown bear or grizzly bear in the Yukon Territory: in the central part and further north on the arctic tundra, near the Polar Sea? I wrote to John Storer, Palaeontologist for the Yukon Territory, and asked him. He replied on the 8^th of July 2004:

“I asked the Yukon Government’s bear biologist, and she told me that she had rather little data on the sort you need. However, she did say that the brown bears in Yukon seem to be relatively homogeneous in size, not being larger or smaller in one part of the territory or another except for the few coastal Alaska bears (Kodiaks) that come up the Alsek valley and a few other places.

Adult female brown bears range between 120 and 320 pounds (54.43 kg and 145.15 kg).

Adult males range between 250 and 700 pounds (113.40 kg and 317.51 kg).

The average female is about 220 pounds (99.80 kg), when she emerges from the den.

And the average male is about 370 pounds (167.83 kg).