Tag Archive: Katmai
Brown Bear Mating Behavior
Thus far in my field observations I haven't been able to observe personally any kind of mating behavior via the live webcams available at the Katmai National Park. However, Explore.org, the group responsible for hosting the live cameras, also provides a handful of highlight videos from this year and past years, which allows viewers to see footage of different activities they are less likely to stumble upon via the live feeds. I found one such video, a highlight video entitled "Bear 856 Pursues Female Bear 410 at Brooks Falls, Alaska", which provided a small glimpse of some of the brown bear mating behavior . It's a relatively short clip, less than two minutes in length, and shows the male bear 856 following female bear 410 as she walks around Brooks Falls. He walks into the frame from the right side, she makes her way toward the far bank, and begins to move more quickly downstream, almost running. He pursues her back upstream, around the small sandbar, back to the fall pool, up over the falls, toward the foreground and along the lip, before the clip ends. Their pace is never very fast, although at times she seems to scramble a bit and pick up her pace.
More on brown bear mating behavior to come…
Tags: animal behavior, Brooks Falls, brown bears, Coursera, field notes, Katmai, mating, video
A Swim at the Mouth of Brooks River
Filed under: Katmai Brown Bear Field Notes — 1 Comment
While the Brooks Falls webcam at Katmai National Park is more popular and seems to have a great deal more activity on a daily basis in terms of brown bear-watching, I was determined to find some bears at the other cam, downriver at the mouth of Brooks River, at the Lower River webcam. After several days of checking in there, I finally caught a glimpse of a bear there for enough time to feel like it was worth including here. Following my previous conventions, I'll refer to this bear as Bear G.
First, a note about the Lower River webcam. While the Brooks Falls webcam seems to focus almost exclusively on the Falls themselves, with an occasional pan to the right to see downstream a bit, the Lower River webcam covers a much wider area near the mouth of the Brooks River. It seems to pan across an almost 360-degree space, including the mouth of the river, a pedestrian bridge crossing the river, and a somewhat marshy-looking area of the river banks with taller grasses, a bit farther upriver from the mouth. Depending on the time of day and the amount of activity in each spot, the camera could be focused on any of these areas, or somewhere in between. There definitely seems to be an "operator" of some kind who monitors the camera, panning and zooming based on when there are bears or other interesting things present, and moving the camera to different views of the river from time to time.
So… around 1:15pm local time today, I saw Bear G near the mouth of the Brooks River, walking across a small strip of land at the farthest point near the river's mouth. Bear G is light brown to dark blonde in color, with a roundish-dish-shaped face, darker fur on its legs and chest, and a darker patch of fur on the back of its neck. It seems to have a slightly short, perhaps upturned snout, and seems a bit thinner and smaller than some of the other bears I've seen. No other distinguishing marks were visible due to the distance. Bear G walked along the narrow strip of land, sat at the end of the point of land for a moment or two, looked around, scratched itself behind the ear in much the way you would see a domestic dog scratch itself, then turned, walked back a bit, and went into the water away from the camera and began to swim off to the left. It would stop every so often and sort of get into a standing posture, look around, then go back into a swimming posture. After swimming off diagonally to the left a bit, it turned, swam directly right back toward the land, where it eventually came out of the water further to the right from where it had gone in, and began to walk back off to the right, off camera.
It wasn't entirely clear to me what behavior the bear was demonstrating here. It may have been foraging for fish (though it did not catch any if it was fishing), may have been looking for another bear, may have been performing some kind of recreational activity (just swimming for fun), or something else.
Tags: animal behavior, brown bear, Coursera, field notes, Katmai, Lower River, MOOC, swimming
Field Observation Animals: Brown Bears
To serve as an introduction to the species before I begin logging my own observation notes, here's a brief overview of the brown bears found in Katmai National Park. Their scientific name is Ursus arctos; they are commonly known as both the brown bear and the grizzly bear. From what I've been able to tell so far, the difference between the two is somewhat arbitrary, and has more to do with where they're found rather than an actual difference in genetics. Those bears found closer to the coasts and relying more heavily on fishing (such as the ones at Katmai), are known as brown bears, while those found further inland, and may have access to mountain goats, sheep, and moose, are more often known as grizzly bears, a subspecies of brown bears (Ursus arctos horribilis).
Geography & Habitat
Brown bears occur throughout Alaska except on islands south of Frederick Sound in southeast Alaska, west of Unimak in the Aleutian Chain, and Bering Sea islands. They also occur in Russia, northern China, northern Japan, Europe, western Canada, and in limited portions of the northwestern United States. (Source: Alaska Department of Fish & Game)
Image Source: Alaska Department of Fish & Game
Katmai's brown bears are some of the largest bears in the world. They can stand 3-5 feet (.9-1.5 m) at the shoulder and measure 7-10 (2.1-3 m) feet in length. Most adult males typically weigh 600-900 pounds (272-408 kg) in mid-summer. By October and November, large adult males can weigh well over 1000 pounds (454 kg). Adult females average about 1/3 less in weight than adult males. (Source: National Park Service)
Brown bears in the wild can live for 20 to 30 years, although most brown bears die in their first few years of life. In captivity, brown bears have been known to live up to 50 years. (Wilson and Ruff, 1999)
Fur is usually dark brown, but varies from cream and light blonde to almost black. Individuals in the Rocky Mountains have long hairs along the shoulders and back which are frosted with white, giving a grizzled appearance, hence the common name grizzly bear in that region. Brown bears are extremely strong and have good endurance; they can kill a cow with one blow, outrun a horse, outswim an Olympian, and drag a dead elk uphill.(Source: Animal Diversity Web, University of Michigan Museum of Zoology)
Mating & Reproduction
Brown bears mature sexually between 4-6 years of age, but continue growing until 10-11 years old. Bears have been known to live and reproduce in Yellowstone Park at 25 years of age, and potential lifespan in captivity is as great as 50 years. (Wilson and Ruff, 1999)
Female brown bears copulate with multiple males during estrus, which lasts 10 to 30 days. Males may fight over females and guard them for 1 to 3 weeks. Female receptivity is probably communicated by scent marking throughout her territory. (Wilson and Ruff, 1999)
The brown bear mating system is polygynandrous (promiscuous), and takes place from May to July. Fertilized eggs develop to the blastocyst stage, after which implantation in the uterus is delayed. The blastocyst becomes implanted approximately 5 months after mating, usually in November when the female has entered her winter sleep. A 6 to 8 week gestation follows, with births occurring from January to March (usually while the female is still in hibernation). Total gestation time, including pre-implantation, ranges from 180 to 266 days. Females remain in estrus throughout the breeding season until mating occurs and do not ovulate again for at least 2 (usually 3 or 4) years after giving birth. Two to three offspring are generally born per litter. (Source: Animal Diversity Web, University of Michigan Museum of Zoology)
Cubs are born in the den during January and February. Twins are most common, but litter sizes can range from 1 to 4. When the cubs emerge in June, they may weigh up to 15 lbs (7 kg) and they actively explore their world under the constant supervision of their mothers. Mothers can be furiously protective of cubs, however less than half of the cubs survive. Families typically stay together for 2 or 3 years and after separation female cubs tend to stay near where they were raised while males go farther afield. Most brown bears are sexually mature at 5 years old; however females often do not successfully produce a litter until later. The mating season is in the spring (May to July) and they are serial monogamous (have one mate at a time, but several each year). The oldest brown bear in Alaska was a 39 year old female, while the oldest male was 38. (Source: Alaska Department of Fish & Game)
Image Source: National Park Service
Tags: animal behavior, brown bear, Coursera, field notes, Katmai, MOOC
Field Observation Site: Katmai National Park, Alaska
The brown bears I'm observing for my field notes assignment are found in Katmai National Park & Reserve in Alaska, USA. According to the Katmai website, there are approximately 2,200 brown bears inhabiting the Park, and, in their words: "As many bear populations around the world decline, Katmai provides some of the few remaining unaltered habitats for these amazing creatures. At Katmai, scientists are able to study bears in their natural habitat, visitors are able to enjoy unparalleled viewing opportunities, and the bears are able to continue their life cycle largely undisturbed."
For a geographical context, here's a series of sequentially more zoomed-in maps (via Google Maps) of the location of Katmai National Park & Reserve in Alaska, the Brooks River & Falls, and the corresponding live webcams which allow for Internet-wide viewing of brown bears at Katmai.