Filling the Gaps

December 10, 2017 / Mike Fitz / 3 Comments

Last July on bearcam, we witnessed the ascent of 32 Chunk in the hierarchy at Brooks Falls. Chunk was the largest bear to consistently use the falls in July, and most bears didn’t challenge him. We watched Chunk interact with many bears, occasionally with some that I (and many bearcam watchers) didn’t recognize. In mid July, for example, we saw Chunk displace another large adult male.

GIF of bear on left moving away from approaching bear who appears at right.

In this GIF from July 2017, a unidentified bear avoids the approach of 32 Chunk.

At the time, a few bearcam watchers speculated the subordinate bear may have been 856, who was the most dominant bear at Brooks River for many years. As I wrote in a previous post, I didn’t think this was 856. So who was it? Was he a previously identified bear or a newcomer to the river?

Before his seasonal position ended this fall, Ranger Dave from Katmai posted photos of several bears who were seen along the river, but were unknown or unrecognized by webcam viewers. Assuming Ranger Dave’s IDs are correct, which they are much more often than not, the unknown bear in the GIF above could be #611.

Bear 611 at Brooks Falls in 2017. Photo courtesy of Dave Kopshever and Katmai National Park.

611 is a bear I don’t know much about. According to my notes, he was first identified in 2015, but only in September and October not in July. Preliminary bear monitoring data from that fall state this bear was an older subadult or young adult at the time.

611 in September 2015, the first year he was identified. NPS photo.

I may be splitting hairs or misunderstanding Dave’s intent, but note that Ranger Dave said, “This is believed to be 611” when he posted the photo. Perhaps there’s still some uncertainty regarding the ID. Filling in the gaps of who’s who at Brooks River can be difficult, and it isn’t possible to identify every bear with certainty. But—based on scars, size, head shape, and ear color—I am fairly convinced the bear in the 2017 photo posted by Ranger Dave is the same bear that Chunk displaced in the GIF above.

At Brooks River, I made the effort to learn to recognize the bears who used the river frequently. Since bear behavior is often complex and can vary from animal to animal, recognizing individual bears leads to a better understanding of their growth, behavior, and strategies for survival. If 611 returns in 2018, we’ll have another opportunity to observe his behavior. Will he challenge other adult males for fishing spots or will he avoid confrontation more often than not? Whatever happens, it will allow us to learn just a little more about the bear world.

Late Season Bears on Dumpling Mountain

October 17, 2017 / Mike Fitz / 8 Comments

Dumpling Mountain, in west-central Katmai National Park, rises gently between Naknek Lake and Lake Brooks. Overridden repeatedly by glaciers during the last ice age, its slopes contour less abruptly than taller mountains to the east. About half the mountain’s topographical prominence lies above timberline. The upper mountain is a chilly, wind-swept place (especially in mid October) where only hardy, ground-hugging shrubs and forbs grow.

Tundra on upper Dumpling Mountain on August 22, 2015

Tundra on upper Dumpling Mountain on September 30, 2015.

The Dumpling Mountain Cam recently captured footage of a mother bear and three yearling cubs there.

The Dumpling Mountain Cam is located about 2,150 feet above sea level on the mountain’s dry alpine tundra, just under 300 feet below and .75 miles distant from the mountain’s 2,440-foot high summit. I hiked up Dumpling Mountain dozens of times, mostly to escape the relative hustle and noise of Brooks Camp, but I rarely saw bears on the mountain. Tracks, sure. Scat, definitely. But bears? Almost never. They don’t use the mountaintop as frequently as other areas. So why would bears venture nearly to the summit of Dumpling now? Are they migrating to a denning site?

Last fall, in a blog post for explore.org, I discussed what is known about the denning habits of Brooks River’s bears. From limited radio tracking studies done in the 1970s, we know these bears probably den on steep, well-vegetated slopes that collect a lot of snow. The same study determined Katmai’s bears denned, on average, at 1,300 feet in elevation.

Dumpling Mountain offers much suitable denning habitat. Although none of the bears radio-collared at Brooks River in the 1970s were tracked to it, I found at least three areas with bear dens in my explorations of the mountain. None are visible within the Dumpling Cam’s viewshed, but they aren’t very far away either.

Screen shot from Google Earth. Purple polygon is viewshed of Dumpling Mountain Cam. Text reads: "Dumpling Mountain Cam" "Bear Dens" "Bear Dens" "Bear Den in Video"

All the dens I found on Dumpling Mountain were around the 2,000 foot elevation line or lower. The purple area represents the Dumpling Mountain Cam viewshed.

Person squatting in entrance to bear den.

Yours truly sits at the entrance of a bear den on Dumpling Mountain.

Bear dens are cozy places. An entrance tunnel leads to a sleeping chamber, which is usually just large enough for the bear crawl into and turn around. Brown bears have the strength and endurance to dig their dens quickly, but den excavation typically takes place over several days. They may also make several excavations near their denning site, perhaps aborting these first attempts due to poor soil conditions.

Bear abundance at Brooks River peaks in late September and early October then decreases coincident with fewer spawning salmon. The bears’ migration away from the river doesn’t necessarily mean they’ll immediately head to their denning site. Bears can still find opportunities to feed elsewhere, even on Dumpling.

These bears on Dumpling may not have been moving to a denning site. Instead, they could’ve been there to eat. Their time on camera showed them traveling, playing, and grazing. Crowberry (Empetrum nigrum), alpine or bog blueberry (Vaccinium uliginosum), and lingonberry (Vaccinium vitus-vitae) all grown on the mountain’s tundra and can be important, and easily accessible foods for bear. Wild berries in Katmai are a fickle crop though. Some years, berry plants produce bumper crops, while in others I was hard pressed to find many berries at all. When one or all are abundant, however, berry-filled scat reveals the bears’ motivation on the mountain. In October, all three species can linger on the bush, but lingonberries are most likely to remain abundant into fall.

Lingonberry (Vaccinium vitis-idaea)

dark purple bear scat on ground-hugging shrubs

This dark purple bear scat is filled with black crowberry (Empetrum nigrum).

Bog or alpine blueberry (Vaccinium uliginosum)

Dumpling Mountain offers several things bears need—food in the form of seasonally abundant berries, open space relatively free of human disturbance, and pockets of prime denning habitat. Bears using the mountain, especially in the fall, could be there to locate a denning site, to graze frozen berries, or simply on their way from one place to another.

Addendum:

Some bearcam viewers have speculated the bear family recently seen on Dumpling Mountain was 854 Divot and her three yearlings. While the video evidence is inconclusive I saw Divot on Dumpling Mountain in the spring of 2015, so the mountain is part of her home range.

What is Hyperphagia?

October 7, 2017 / Mike Fitz / 3 Comments

Side-by-side comparison of bear in late spring and late summer. Text reads, "747 June 13, 2107" "747 September 11, 2017"

Photos of bear 747 from late spring and late summer illustrate this bear’s substantial weight gain. Photos courtesy of Katmai National Park.

As we’re in the midst of Fat Bear Week, it’s a good time to ponder some of the mechanisms that allow bears to gain enough weight to survive hibernation. Bears get fat to survive and hyperphagia is how they do it. In the bearcam week in review for October 5, I briefly explained hyperphagia. Here it is in case you missed it.

Bears experience hunger in ways humans do not. They need to eat a year’s worth of food in six months or less to survive winter hibernation and the lean months of spring. To do this they eat A LOT, especially at this time of the year.

In bears, hyperphagia is the period of excessive eating which takes place in late summer and fall. During this time black bears will eat 20,000 calories of food per day. Katmai’s brown bears can easily eat even more by catching calorie-rich salmon. Even though their calorie intake is extremely high, hyperphagic bears don’t feel full.

Satiety is the feeling of fullness after a meal. During hyperphagia, a bear’s body temporarily suppresses the normal mechanisms that balance food intake with weight gain. The body says, “You aren’t full. You don’t have enough fat reserves and need to eat more.” In short, hyperphagic bears don’t feel sated. This contrasts with the excessive eating of bears in June and July when they are eating a lot, but their bodies probably still respond to a feeling of fullness (which is sometimes hard to believe when you watch Otis or 747 catch fish after fish after fish). Hyperphagia, therefore, is a physiological state of bears in late summer and fall, as much as it is a behavior we can see. It’s how they prepare to survive the famine ahead.

747 should be your choice for Fat Bear Week

October 3, 2017October 3, 2017 / Mike Fitz / 18 Comments

There are small and fat bears, old and fat bears, young and fat bears, just plain fat bears. But none, NONE I say, are as fat as 747 in 2017. He has earned my official endorsement in the 2017 Fat Bear Week tournament.

fat bear walking in shallow water near grass

747 displays his massive silhouette near Brooks Falls on September 6, 2017.

747 is a mature adult male in the prime of his life. He has gained at least as much and probably more weight than all others. In my opinion, 747 is the biggest and fattest at Brook River.

Compare 747’s overall size in late spring…

747 in mid June 2017. Photo courtesy of David Kopshever.

…with his fatness in early September.

747 is so fat, his belly almost touches the ground.

Still not convinced? Then watch this video of 747 from September 6, 2017.

Since then, 747 has gained even more weight.

Too much fat is unhealthy for humans, but fat is essential to the survival of brown bears. It is a savings account against famine. Without ample fat, bears do not survive hibernation. In spring, often a season of starvation for bears, females with cubs will metabolize fat into milk to nurse their growing cubs, and adult males will use their fat to fuel their pursuit of mates.

747 won’t be rearing any cubs next spring as male brown bears play no role in raising offspring. During a season when almost no high calorie foods are available to bears, 747 will use his fat to roam the landscape for mates instead.

747 faces some tough competitors in this year’s tournament, but don’t fall for any other fat bear propaganda from the fake news mainstream leftwing socialist progressive liberal media. 747 is larger and fatter than any other bear at Brooks River. He’s huge, tremendous, and will win “bigly.”

2017 Fat Bear Week bracket with 747 as champ

This is my 2017 #FatBearWeek bracket. I look forward to seeing your bracket and campaign posters in the bearcam chat on explore.org.

Testing the Water

October 2, 2017 / Mike Fitz / 2 Comments

At Brooks Falls, most bears tend to focus their efforts at one or two fishing spots. More rarely, a bear will learn to fish successfully almost anywhere at the falls. 503 has used several different fishing spots at Brooks Falls this year—the far pool, near the downed log, the jacuzzi, and the lip. Is he learning to become a generalist angler or will he eventually specialize in a particular spot? Bears from Brooks River’s past and present can offer us some insights into 503’s potential future. Read more in my latest post on explore.org.

Injured Nose Bears

September 29, 2017September 29, 2017 / Mike Fitz / 7 Comments

It’s not uncommon to see bears with open wounds and distinctive scars, like bear 83 who seems to repeatedly get injured.

Photo of 83’s wound from 2015. In 2016, his rump was injured again courtesy of bear 747.

Wounds and the subsequent scars are useful when identifying Brooks River’s bears, since each bear carries a unique suite of them. 83 now sports a large scar on his rump.

The lump on 83’s rump marks the scar from his 2015 injury.

Sometimes though, we see bears with scars or injuries that may be more than superficial, perhaps impacting the sense they rely on most.

On September 13, 2017, a bear with a large, distinctive scar on his left shoulder was photographed at Brooks River.

Photo courtesy of Lee (aka RiverPA) via Flickr.

Most distinctively, his nose is split.

Photo courtesy of Lee (aka RiverPA) via Flickr.

This appears to be an old injury and when I saw these photos I wondered have we seen this bear before?

In 2010 and 2011, a subadult bear with a torn nostril was seen at Brooks River. Bear 253 was a young subadult at the time, but Katmai’s bear monitor was not able to determine its sex. Its nose was most likely injured in 2010 as photos from 2011 show some healing.

Bear 253 on September 6, 2010. NPS photo.

Bear 253 on October 8, 2010. NPS photo.

Bear 253 on September 6, 2010. NPS photo.

Bear 253 on September 17, 2011. NPS Photo.

Bear 253 on September 27, 2011. NPS Photo.

Bear 253 on September 17, 2011. NPS Photo.

253 probably isn’t the unidentified male photographed with the nose injury this past September though. 253’s muzzle is long and somewhat pointed while the male bear’s muzzle is blockier in shape. The nose injury on the male bear also seems more symmetrical than 253’s.

Would injuries like these impair these bears’ sense of smell? Perhaps, especially if it reduced the surface area inside the nose where scent can be detected.

Bears have a legendary sense of smell. The inside of their nose is filled with many turbinals, a complex scaffold of paper-thin bones. Humans have turbinal bones too, just far less than ursids. In black bears, for example, these bones greatly increase the surface area inside the nasal cavity, providing 100 times more nasal mucosa, or mucous membranes, than humans. More tangibly, if the area of muscous membranes inside the human nose equals the area of your typical postage stamp, then the area covered by mucous membranes inside the black bear nose covers an 8.5 x 11” sheet of office paper. On the surface of the membranes are millions and millions of scent detecting cells. In short, bears live in a world of odors we can scarcely imagine.

Like human eyesight, hearing, and smell, the strength of these senses likely varies in bears. Some bears may have worse eyesight than others (although it’s a myth that bears have poor eyesight; they don’t). Others may have worse hearing. In the case of bears with injured noses, they may not be able to smell as well as their cohorts. (It’s important to note that in the case of 253 and the adult male seen this past September, the injury to their nose may not be deep enough to affect the turbinals.)

If bears are anything though, they are tough survivalists. A nose injury could impose a severe disability on them, but that won’t stop them from doing whatever they need to do to survive.

My Trip to Brooks Camp 2017: Day Four

September 20, 2017 / Mike Fitz / 12 Comments

Rain falling on a tent is the least motivating sound in the world and I heard it off and on through my last night in the Brooks Camp Campground. But by dawn, the rain nearly ceased and since this was my last morning to watch bears, I wasn’t about to let some drizzle get in the way of bear watching.

First, I had to get to the river. The campground is set almost a half-mile from the mouth of Brooks River. The walk between is easy enough, mostly flat and over crushed gravel trails, unless bears get in the way. After exiting the campground’s electric fence (5,000 volts of shock value), I stepped on to the beach to check if it was free of bears.

The trail to and from the campground parallels the beach, a place bears utilize frequently as a travel corridor or a place to rest. When bears are on the beach they are generally too close to the campground trail for it to be used. That morning, in the dim blue-gray light of an overcast dawn, I could see one bear sleeping between the visitor center and me. Giving this bear space was simple enough, all I had to do was swing through the forest and follow the faint trace of the waterline that ran to the campground. The risk in this plan though was the limited visibility in the forest. I moved slowly, watching and listening carefully for bears. The few belly holes along the route were empty and I safely reached the main trail with only a few moments lost.

At the river mouth, plenty of bears were active. 409 and her yearlings fished near the bridge and 410 stood still on the spit when a new family of bears appeared, one that I hadn’t yet seen in person. It was 435 Holly and her two very plump spring cubs.

bears standing on edge of lake with mountains in background

435 Holly and her two spring cubs stand near 410 on the spit at the mouth of Brooks River.

Crossing the river wasn’t as straightforward as the previous morning though as 409 and her two yearlings fished within a few yards of the bridge. As the family slowly made their way downstream, I prepared to speed walk across the bridge when the opportunity arrived. Just as 409 and her cubs waded far enough downstream of the bridge (more than 50 yards) I crossed quickly, and just in the nick of time. As soon as I reached the lower river platform, 854 and her cubs appeared on the Corner where I was standing.

Photo opportunities are limited with my durable but optically limited waterproof camera. Still, over the next 150 minutes, I watch 14 different bears (23 counting dependent offspring) using the lower Brooks River.

Bear 879

854 Divot and her yearling cubs

708 Amelia and one of her 2.5 year-old cubs.

group of 11 black and white magpies in grass

Magpie convention

With my time at Brooks Camp running low, I ventured to the falls for one last look at the largest of the river’s bears. 32 Chunk, 151, 474, 480 Otis, and 747 round out the adult male roster this morning. When 747 sees 474 walk upriver, 747 directly approached 474. Both of the palindromic-numbered bears began to cowboy walk and mark trees, 474 on the shore near the platform and 747 on the island downstream of the falls. When 474 moved behind the platform, likely as a subtle move to avoid 747, the larger 747 marked the same tree and urinated in the same places as 474. Out of the water, 747’s true size is revealed. He’s a giant of a bear, far fatter and larger than any other on the river.

Bears use scent marking and body posturing to communicate their relative level of dominance. This morning, 474’s avoidance of 747 and 747’s subsequent scent marking of the same spots indicate 747 was the dominant bear, which is not surprising based on his gigantic proportions.

Before I left the falls for the final time (this year at least), I watched a young subadult bear fish the lip. She appeared well practiced in this spot. Bears rarely fish the lip of the falls in late summer, a time when nearly all salmon have reached their spawning site and lack the energy reserves or motivation to surmount the falls. The abundance of silver salmon in the river this year, however, allowed her to exploit this fishing spot during a time when it usually wouldn’t be worth visiting.

This young subadult has fished the lip of Brooks Falls often recently. While bearcam viewers have speculated she might be one of 402’s emancipated cubs, this bear looked too big for a 2.5 year-old.

I encountered no significant delays on my return to the lodge to check in for my flight out. Lots of bears milled around the lower river, but I remained on the beach in front of the lodge to sit and watch 435 Holly and her cubs rest nearby.

435 Holly and spring cubs

Brooks River is a special place, unique among national parks, and I felt fortunate to spend time there once again even if the visit was too short.

My Trip to Brooks Camp 2017: Day Three

September 19, 2017 / Mike Fitz / 15 Comments

When you enjoy watching wildlife as much as me, you don’t want to waste time with biological tasks like sleeping. Still, sleep is a necessity and I can’t watch bears in the dark. After a reasonably restful night, I woke before sunrise and left the campground when there was just enough light for me to see without a headlamp or flashlight. This would be my last full day at Brooks River in 2017 and intended to make the most of it.

Early morning hours at Brooks River are generally quiet. Planes haven’t arrived and most people are either sleeping or focused on breakfast. The dominant sound at this hour tends to be the cry of glaucous-winged gulls.

Bears like early morning meals just as much as people, and I fully expected to find bears too close to the trail or bridge for me to reach the relative safety of the lower river wildlife viewing platform. Luckily, the corridor from the lodge to the bridge and the platform was clear before 7 a.m. In a short while, however, bears filled the void and for much of the rest of the day the bridge would remain closed to people.

When I first reached the platform, only 409 Beadnose and her yearlings were visible. Her cubs behaved quite independently, catching most of their own salmon. Yet they remained prone to begging food from their mother and bawling when they want to nurse. Two subadults entered the river upstream of the platform. 410 made the most of her chance for breakfast, eating at least five salmon carcasses in a half hour. It was still too dark for my point-and-shoot camera to take clear photos, so I sat back, watched, and took notes.

409, her cubs, and two young subadult bears all eventually wandered toward the river mouth and the beach in front of the lodge, allowing more people to cross the bridge. As the platform got noisier, I decided it’s a good time to wander to Brooks Falls.

The walk to the falls is quiet and uneventful, but bears used the trail just moments before. Foam clung to the surface of a large puddle of urine and bright red, relatively undigested lingonberries polka dot the surface of a fresh pile of scat.

Even with the high abundance of salmon, bears were still feeding on berries.

The falls platform was empty when I arrived and no one else arrived for the next hour as bears remained too close to the bridge for people to cross. Within my experience at Brooks Camp, it’s rare to have the falls platform to yourself when bears are around.

I quickly forgot about being alone though as bears were quite active. 410 had made her way from the lower river to the falls where she fished her normal spot in the far pool. 68 was giving it a shot in the jacuzzi. Both bears ignored each other and remained separated by about 30 yards. When 747 arrived 68 quickly moves out of the jacuzzi to make way for the larger bear.

After 747 decided to push the other bears around, 503 appeared in the far pool. While 747 is absolutely the largest bear at Brooks River, I was shocked at 503’s size. He’s not particularly fat, but’s he’s very big for his age. Bears grow quickly yet I don’t recall ever seeing a 4.5 year-old brown bear as big as 503.

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503’s story is well documented here and here.

Returning to the lower river, I watched more subadult antics. Now after 10 a.m., the bridge had not yet opened because bears were consistently within 50 yards of it. Four to five subadult bears, all of which I saw the previous day, fished and played nearby.

409 Beadnose and her yearlings wandered toward the bridge from the lake to rest.

Around 11:30 a.m., I contemplated crossing the bridge to eat lunch. At Brooks Camp food can only be eaten inside of buildings or at designated picnic areas. Possession of food, unless actively transporting it from one designated area to another, is also prohibited. With lots of bears in sight, I reasoned I could ignore my hunger pangs and eat later.

Upstream, 854 Divot and her yearlings scavenged for fish. Not yet having the opportunity to observe them much on this trip, I waited for them to fish their way downstream. Fall bears have a pattern though; they fish then sleep. Many human-habituated bears—especially 854 Divot, 409 Beadnose, 410, and 435 Holly—often choose to sleep near the trail between the lodge and the river. When that happens, the trail is usually closed until the bears wake and move on. I knew I risked a long delay getting to and fro if Divot and her cubs chose to sleep near the bridge or trail.

Which they did. At 12:10 p.m., Divot and cubs settled in for a nap on the bank just upstream of the floating bridge. With no alternative route around the bears, the bridge and trail were closed. There was nothing to do but wait. Bridge closures and Brooks Camp’s famous bear jams can be frustrating situations for people unaccustomed to them or too impatient for them, but bears need the habitat near the mouth of the river as much as they need the falls. To make a long story short (one I hope to tell in greater detail in the future) 854 slept in that spot for two hours and with many other bears fishing in the river, the bridge didn’t open for over three hours.

A half hour after crossing the bridge though and refreshed after a quick snack, I was back at the river when word of Otis’s arrival at Brooks Falls spread among the staff. Not knowing if I’d get another chance to see him before leaving the next day, I skipped bear viewing at the lower river to go to the falls, where I found 480 Otis as well as 68, 503, 719, 747, and an unidentified subadult.

480 fishes in his office at Brooks Falls shortly after arriving. 747 sits in the water nearby.

Rain moved through later in the evening, but I still had one more morning of bear watching to enjoy before my flight out.

My Trip to Brooks Camp: Day Two

September 18, 2017 / Mike Fitz / 19 Comments

Due to strong winds, I was unable to reach Brooks Camp on time. The next morning, as instructed by Katmai Air, I arrived at their dock before 7 a.m. I was eager to get on the “first load.” Evidently everyone who didn’t reach Brooks Camp the previous day was told they’d be on the “first load,” which caused Katmai Air to deal with some cranky customers. (Not me, I might add, but I understood others’ frustration.)

Looking southwest toward Mount Brooks from the air.

Around 8:40 a.m., I arrived at Brooks Camp—or Lake Brooks to be exact. Winds out of the east were still too strong for planes to land on Naknek Lake, but I didn’t mind the view of Dumpling Mountain and the head of Brooks River.

Dumpling Mountain and the outlet of Lake Brooks

After heading straight to the visitor center to get my bear orientation…

Yes, even former rangers are required to attend the bear safety talk upon arrival at Brooks Camp.

…I hurriedly pitched my tent in the campground….

My tent in the far southwest corner of the campground, as far away from other people as I could get.

…and walked back to the lower river to binge watch bears.

Fine pumice sand, evidence of the powerful winds from the previous day’s storm, was all over the beach.

In September, the wildlife-viewing platform near the mouth of Brooks River is my favorite place to be. Upstream, just where the river enters my line of sight from the platform, thousands of salmon work to complete their life cycle. As the fish weaken and die, the river’s current sweeps them downstream. Where the river’s current is not longer strong enough to carry them further, it drops the barely live and dead fish, making the river mouth and meanders just upstream the most productive salmon scavenging areas at Brooks.

When I arrive on the platform four subadult bears play and fish, while 409 Beadnose and cubs lounge nearby. After another large salmon run, the bears at Brooks River are well fed, and perhaps as a result the younger bears were especially playful.

brown bear standing with front paws on boulder

One light brown subadult bear out of this bunch very much resembles 273’s yearling in 2016. This bear appears to be a young subadult, but is large for a 2.5 year-old.

Around noon, after Beadnose and cubs settled into a nap below the platform, I decided to visit Brooks Falls, where bears had been fishing in higher than average numbers for this time of year. I had a hypothesis as to why, but I needed at least a few cursory observations to support it.

Over my short stay, the vast majority of fish I saw bears catch at the falls were silver (coho) salmon. This run begins in August and often continues through September. Larger on average than sockeye, a single, fresh silver salmon can provide several thousand calories for bears skilled enough to catch them. Like the beginning of the sockeye run in late June and July, the late run of silver salmon is most accessible to bears at Brooks Falls.

Two adult male bears, 68 (left) and 879, fish the far pool of Brooks Falls.

But bears in the lower river make huge energy profits as well. In the early evening, after skipping a true lunch to eat an early dinner (to maximize bear watching time), I return to the lower river until sunset. 410 and 409 Beadnose both patrol the river slowly, snorkeling for any salmon that can swim away. In a half hour, 410 eats four fish. Over an hour, Beadnose leisurely consumes eight. These are relatively low catch rates for this section of river, yet even assuming the salmon carcasses provide less than half the energy they did in July (spawned out fish may contain 2000-2500 calories or less compared to the 4500 calories when the first arrived) 410 and 409 still ate at least 8,000 and 16,000 calories respectively. In past years, when 410 has remained within my line of sight longer at the lower river, I’ve counted her eating 41 fish in 3 hours 25 minutes. Even if she only ate part of each fish, when your profit is measured in calories needed to survive winter hibernation, this isn’t a bad day’s work.

As the sun begins to set behind the western toe of Dumpling Mountain, I relaxed to watch bears come and go from the river—128 Grazer, 409 Beadnose, 284, 410, 708, 610, four unidentified subadults, 879, 474, and many cubs. If the sun didn’t set so soon and I didn’t risk running a gauntlet of bears in the dark to get to the campground, I would’ve remained out for much longer. Responsible bear watching, however, includes not wandering around in the dark, so I retire to the campground eager for sunrise and another day on the river.

There is no average bear

August 21, 2017 / Mike Fitz / 12 Comments

In many ways, we can stereotype bears based on their age, sex, and reproductive status. While watching bears and even interacting with bears, certain stereotypes are useful. They help us begin to understand and explain a wide spectrum of behavior exhibited by a group of intelligent animals.

To stereotype a group of bears, adult males who rank at or near the top of the hierarchy are probably the least likely to act like a kid. They are the least likely to play or show overt curiosity towards new things. For most of bearcam’s history (2012-present) we’ve watched bears like 856, 747, and 814 dominate the falls through their size and assertiveness. These bears showed little interest in other bears except when establishing or reaffirming their dominance, stealing fish (especially 814 Lurch), appropriating preferred fishing spots, or when seeking a mate. Their behavior framed (biased?) our expectations of bears at the top of the hierarchy. They acted like stereotypical dominant males, and in their own ways, average bears.

But this logic can only take us so far, because there are no average bears.

This past July 32 Chunk displaced 856 as the most dominant bear at Brooks River. Chunk is approximately 12-13 years old and is perhaps the largest bear to use the river regularly this summer. Much of his behavior, especially early in Brooks River’s salmon run, is typical of a big dominant male. Not only did he displace other bears, he also wasn’t successfully challenged for food or fishing spots.

Notice how 856 quickly vacates the jacuzzi and doesn’t even attempt to challenge 32 Chunk.

Initially, 32 Chunk fit our expectations of a dominant male, but over the past two weeks or more bearcam has captured Chunk play fighting with another large, and older adult male, 755 Scare D Bear, as well as scavenging fish from him.

Just what is going on? Has Brooks Falls gone topsy-turvy in the wake of this summer’s hierarchy shift? Or this something more akin to the peculiarities of individual bear behavior during a summer when salmon are plentiful?

In July especially, Chunk fit the stereotype of a dominant adult male—challenging and displacing other bears, marking trees and cowboy walking in full view of other large males, and courting females. Since then, he’s behaved in ways that do not fit the dominant male stereotype—waiting patiently downstream of 755 for scraps of fish (a behavior more akin to scavenging than begging) and even initiating prolonged play fights with 755.

Play among adult male bears in their early teens is uncommon, but not unprecedented. I’ve previously wondered if bears outgrow play, and my personal observations suggest the frequency of play decreases as bears age. (I’m more surprised by 755 Scare D Bear’s willingness to play-fight, something I’ve never witnessed from him, than from 32’s).

Chunk’s play behavior separates him from bear 856 who was the most dominant bear seen through the entire history of bearcam until this summer. 856, like 24 BB before him, was hyper-dominant. As far as I know, this term has never been formally described in the scientific literature about bears. Tamara Olson, one of Katmai’s former bear biologists, introduced me to it. As I understand the term, hyper-dominance in bears is a willingness to continuously assert dominance over other competitors, giving them no slack, no chances to gain an edge. 856 became the river’s most dominant animal in 2011, when he was about the same age as Chunk is now. Once 856 became more dominant than 814 Lurch, for example, he repeatedly approached and displaced Lurch, perhaps in an effort to remind his large competitor, “Don’t challenge me or infringe on my space.”

Perhaps a lack of other large males who can challenge Chunk has allowed him to exhibit more playful and less hyper-dominant behavior. The relatively high abundance of salmon at Brooks River this summer also influences how bears interact with each other. To add another stereotype to the mix, bears are generally more playful and more tolerant of each other when they are well fed.

Because of his rank at the top of the hierarchy, we expect Chunk to behave like more like 856 than a youthful subadult. However, no biological edict commands Chunk to fit our expectations. His bimodal behavior is uncommon among adult male bears of his rank. Yet, Chunk can play-fight with other bears and still maintain an exceptionally high rank in the hierarchy.

The average bear is an amalgam of our observations and conclusions, created to help us better understand the lives of bears. No single bear will ever fit this role completely. Chunk can be both playful and dominant. He is no anomaly, because the average bear doesn’t exist.

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Wandering at Large

explorations and thoughts about the natural world

bears