On woodpeckers and bears

All quiet on the home pond, just a few loafing male mallards and a wandering bunch of big ducklings. Not so, on the suet feeder, occupied by a male hairy woodpecker. An adult nuthatch was taking issue with his occupancy, darting at him repeatedly, making him duck and dodge. Eventually, both birds departed. The nuthatches have been feeding a sturdy juvenile, stuffing it with suet and peanut butter (and insects too, I hope), and perhaps there was a sense of ownership. But it was certainly a surprise to me, seeing that little nuthatch go after the woodpecker that weighs about six times more.

Up on Eaglecrest’s Lower Loop, a three-toed woodpecker was drumming energetically on the top of a tall dead snag. Presently, another woodpecker flew in and they both went off somewhere briefly, and then one came back to the snag. I don’t know what was going on, but that prompted me to learn a little more about their drumming behavior.

Both male and female three-toed woodpeckers drum (as is true of at least some other species too). There are two styles of drumming: fast, which is more common, and slow. Fast drumming typically includes about sixteen hits at an average rate of over thirteen hits per second. It is used primarily for territorial advertisement, often in response to another drummer. Slow drumming  averages about nine hits at a rate of just over eleven hits per second. It occurs between members of a pair, apparently as a way of locating each other and getting together.

There hasn’t been much bear traffic in my yard, but up near the visitor center, a friend made some good observations. Two little bear cubs were up in a cottonwood tree, pulling in branches and snacking on the ripening seed pods, while mama rested at the foot of the tree. One of the cubs started to descend but panicked and started bawling. So mama scrambled up to guide the little fellow down, the sibling cub coming along too.

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Photos by Kerry Howard

A number of years ago, we often saw bears up in the cottonwoods, feeding on male and female flowering catkins and on seed pods, but that activity seemed to have diminished recently, so it was good to hear that our bears still do this. When we first noticed this behavior, years ago, it seemed perhaps a bit unusual and certainly interesting, so we wrote a small paper about it and sent it to a journal. “We” in this case was comprised of me, three very experienced Forest Service rangers, and an ADFG statistician. Well!! The journal rejected our paper, disbelieving our observations—even though black bears all across North America are known to eat catkins of many species! Now, I’ve written a lot of scientific and natural history papers, and as an author, I know to expect journal editors to request revisions, sometimes extensive ones. But this was the only time in a long career that I’ve experienced rejection based on disbelief. Harumph (and a few other, unprintable, words)!  Fortunately, we had more photos of our bears in action in our cottonwoods, and those photos eventually persuaded the journal to accept our paper.

Some of the trees near the visitor center still show signs of bears getting access to catkins and pods: some large branches are missing altogether, broken off when bears pulled them in toward the trunk where they perched securely. Many small branches are gone, too, broken off by bears or by porcupines, which relish the catkins and pods too. We noted that female trees endured heavier damage than male trees, probably because of the extended depredation of seed pods after the floral catkins were gone.

Squirrels and mice relish the seeds in the seed pods too. I find evidence of their work on the ground and occasionally see them in action.

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Fun at Home

I love to walk our trails, just to see what I can see. But sometimes there’s a lot to see in my front yard and pond. Then I wear a path from window to window (with side trips to the fridge and tea kettle). This spring has provided some home-based fun.

The shenanigans of the mallards are an annual happening. The ducks start to visit the pond soon after ice-out. Pairs sort themselves out and by late May mama ducks start to bring their tiny ducklings for an occasional visit. This year there were several brood of eight or nine and one brood of just one duckling.

The littlest ones have a hard time jumping up to join mama on the bank for a rest. They zip back and forth in front of her and make lots of futile little leaps. The female often tries several spots before finding one they can all master. Sometimes only part of a brood makes the jump and the rest have to find access at some distance and make a small overland trek. When ducklings are small, the mother broods them, making herself as broad as possible to cover them all, although even then a few heads and tails poke out from under her.

The unpaired males that have already fathered these broods are hanging about, all revved up and looking for more action. They harass any late-forming pairs and even mothers with babies, causing lots of fuss and flapping. The female with one offspring was persistently pursued, driving her to protest continually and even leave the pond several times. If I opened the windows, I could hear the little one peeping in apparent distress.

A flotilla of visiting ducklings is probably what brought an eagle down to march along the bank, eyeing one brood with malevolent intent. (Yes, I know, eagles have to eat too.) A swoop or two over the water failed, as the brood scooted for cover, and the eagle left, still hungry.

Juvenile juncos had been chip-chipping in the woods along various trails since mid-May. Here at home, there were well-fledged juveniles, of two separate families, by the first week of June, quite able to pick up seeds for themselves but often waiting for dad to deliver. It was the male juncos that stuffed the juveniles with peanut butter and seeds, leading me to suspect that the females were back on eggs again, for second broods. (They can do three or four a year.) The juveniles tried the peanut butter feeder occasionally but looked like they needed some practice, and they preferred to wait for dad.

A male hairy woodpecker made occasional visits to peanut butter and suet, but by mid-June his visits were quite frequent. He hacked out big chunks of suet and carried them off, leaving crumbs for the little birds to pick up. He would swallow several bits of peanut butter but carry away one last load in his bill. So I knew he had a family. And finally, a big, well-feathered fledgling joined his father on the deck railing and begged for peanut butter. I wondered if the mother was tending another young one somewhere.

The chickadees were feeding big kids too. And a great treat was seeing the whole family of nuthatches crowding together on a small block of suet. Two sleek fledglings chipped off bits of suet for themselves, but were also happy to have chunks delivered by the parents.

A bear came to eat horsetail in my front yard. They do this every year. Often they lie down flat and just scoop in the green stuff. This guy got up and wandered up toward the house, sniffing and sniffing, then stood under the edge of the deck to sniff some more. No doubt the aroma of peanut butter was in the air. Before I could say oh-oh, the bear shot up a nearby tree like lightning, just a black blur. It went up above the roof level, out of sight. Now, I’m not too enthusiastic about a bear on my roof (or deck). I raced outside to check the roof, but by then it was already down and gone. The tree was just a bit too far away from roof and deck. But just in case, I have moved the alluring feeder to the other end of the deck; the birds are getting used to the new arrangement.

One more bear story: A medium-size cinnamon bear came and foraged on horsetail. That gave me time to see that she looked like she’d worn a collar for a long time because her fur was very worn in a circle around the neck, but she had no visible ear tags. Eventually, she started to wander out of sight. Immediately, an alder tree across the pond gave a violent shudder, and a massive glossy-black bear suddenly appeared in the yard. He chomped a couple of horsetails but was much more interested in her, and he followed her off into the neighbors’ yard. It’s that time of year for bears!

Watching young animals

The first part of July gave me some very nice opportunities to observe young critters just learning to make their way in the world.

Above the tram in Bear Valley, we watched a bear family foraging on green herbage. Mama was all business, but the cubs were more interested in playing. The two larger ones wrestled and rolled, boxed and bumped, flattening the vegetation after mama had forged ahead. Cub number three was a little smaller than its siblings but eventually trotted out of the thickets to follow the rest.

The forest at the top of the tram gave us a close-up look at a mixed-species flock of birds. First we saw a nuthatch, then a chickadee and a couple of siskins, and then the trees were full of a family of golden-crowned kinglets, including numerous fledglings. Accompanying this gang were two brown creepers, hitching up the tree trunks and acrobatically working along on the underside of branches. The entire flock foraged in plain sight for at least five minutes. Mixed-species flocks are thought to be advantageous to the participants, especially in keeping multiple eyes on the lookout for predators, but all the fluttering activity may also stir up insect prey.

On my home pond, we’ve had the duck wars. Three female mallards have brought broods of ducklings to forage along the pond margins and rest in the weeds on shore. Three broods, all of different ages, and the female with the oldest ducklings tended to rule the waters. She often chased all the others, sometimes very aggressively. Her ducklings were quite well feathered in mid July, and those of the next oldest brood were just beginning to show real feathers amidst the down. Then calamity struck—I heard a female quacking loudly and persistently, and I looked out to see that her brood had just been reduced from four to three. With the remaining ducklings closely huddled around her, she fussed continually for at least two hours, and I finally went out—to discover a sorry little pile of down under the trees on the far bank. I suspect a goshawk had found its lunch. The female went on fussing for another hour or more before accepting the new reality.

A friend and I were scrambling along the bank of one of the tributaries of Fish Creek one day. As the valley narrowed down to a canyon, we practically stumbled over a female porcupine with her offspring. Mama quickly hid her head under a log, leaving her spiny back bristling in our direction. Baby, on the other hand, fiddled around a few minutes, then clambered over a stick and slowly made its way between two tree roots. There if finally did the right thing (for a porcupine) and wedged its head into the fork between the roots and erected its defensive spines over the only exposed part of its little body. This little guy was a tad slow off the mark: baby porcupines can execute the typical defensive maneuvers almost immediately after birth. And this one had had weeks to practice. We left them in peace, of course.

Another friend and I led a guided hike up Gold Ridge on a nice but rather foggy day. There were some spectacular flower shows, and an assortment of marmots, including a young one just poking its head above the flowers. We also had a treat, in the form of a juvenile golden-crowned sparrow. The juvenile looked nothing like its nearby parent except in general shape; it had no strong black and gold crown stripes, but it did have conspicuous almost-golden spangles all over its back. This observation was special, because we’d never before seen a juvenile so close-up, even though this bird nests up there regularly.

We saw one female sooty grouse, with some wee chicks hidden in the low vegetation, and one rock ptarmigan, which might have been guarding an invisible brood. But both grouse and ptarmigan seem to be much less common on the ridge than they were just a few years ago.

Gray-crowned rosy finch adult. Photo by Bob Armstrong

On top of Gold Ridge, we hoped to find gray-crowned rosy finches that nest in the cliffs up there. And, in between swirls of fog, there they were. Adults were feeding fledglings at the edge of a remnant snow bank. The fog made it difficult to see plumage colors, and all the birds just looked black, but eventually we could discern some pattern and distinguish parent from chick. The juveniles were plump, active, and fully capable of doing their own foraging, but –in the way of all young songbirds—they wanted their parents to deliver.

The end of August

A rather dismal August finally dripped to a finish. The sodden ground could hold no more water, so the streams were raging torrents and trails were squishy. The lovely long days of summer were just a memory, as day-lengths shortened rapidly. The fall season in Juneau can be pretty gloomy, but instead of pouting and whining (well, mostly instead), I found some cheering things to see.

Out near the glacier, a very late brood of barn swallows lined the edge of their nest with five widely gaping beaks every time a parent bird arrived. Each time, one lucky nestling would get a bug or two from a busy adult; feeding five big chicks took a lot of work. But all five chicks fledged a day later and were lined up on a fence railing, awaiting food deliveries.

On my home pond, there was another late brood, this one of mallards. A female appeared, trailed by two large offspring that were getting their real feathers. All that was left of the babyish down was a small poof on the rump. These two, about half the size of the female, were the remainder of a brood of five or six ducklings, but both of them, with mama, appeared for many days and finally looked just like her in both size and plumage.

The star of the show near the Visitor Center was a young porcupine, recently abandoned by its mother. That’s normal for this time in the porcupine year. Junior could be seen by numerous enchanted visitors, as it steadily gobbled alder leaves right next to the trail. For variety, it nibbled on some cottonwood leaves or climbed up a willow to demolish more leaves. Its right front leg seemed to be sore and was seldom used, but that didn’t deter the little guy from climbing trees and roaming around the area in search of green delicacies.

A whale-watching tour near Shelter Island found several humpbacks, and soon we were surrounded by them. The adults were placidly diving and coasting along, while a calf was showing off. It breached many time, it lunged repeatedly, and it rolled again and again. Its youthful exuberance entertained us well.

Mixed flocks of migrant songbirds flitted through the shrubbery in several places. Yellow-rumped warblers, ruby-crowned kinglets, Wilson’s warblers, and probably others searched for insects in the foliage. A friend watched an orange-crowned warbler probing both ends of a rolled-up cottonwood leaf in hopes of extracting the caterpillar within. Those masters of fast, erratic flight, the dragonflies, were no match for the wily olive-sided flycatchers, which perched in dead treetops and nabbed the big ‘darner’ dragonflies as they hunted small insects over a creek.

Those of us who hang out near Steep Creek and the glacier were pleased to see an old ‘friend’ appear, strolling on the beach (or what beach there was, given the high waters). This was Na Tláa, the Clan Mother, a.k.a. the grandma bear, who is about twenty-three years old and has not had cubs for several years. She was not very plump and, long after other local bears had their new coats, she was still molting; her back was covered with long, bleached-out, reddish fur, while the rest of her showed shiny black new fur. This old bear foraged on this and that in the vegetation, caught a fish and ate it, looked at more fish in the ex-beaver pond, and eventually wandered on down the lakeshore.

High on the list of fun stuff was an encounter on the Perseverance Trail on the very last day of August. Two friends and I were coming down the trail, just below the Horn (where two benches provide a view of Snowslide Gulch). Some distance ahead of us there appeared a large black lump, followed by two smaller black lumps, moving slowly up the trail. Ooooops! What now?! Steep cliff up on our right, steep cliff down on our left, and nowhere to go but back. So we quietly backed up a hundred yards or so to the Horn, intercepted two other down-hikers, and waited. And there they came, mom and two cubs.

I suggested that we all go up on the little rubble slope on the inside of the curve, to allow the bruins plenty of room between us and the railing. Bad idea! Mom took one look at us and turned around, heading back down the trail. But she hesitated and looked back, as if she really wanted to continue upward. So we all scuttled into a corner of the fence behind the benches. Ah! Much better! The family turned back uphill and sauntered past us—Mom completely calm and owning the trail, the kids a bit skittish. So on they marched, right up the trail. There had been clear signs that some bears had used the trail above, bears that had been eating loads of stink currants. Nevertheless, we hoped they’d find a good place to leave the trail, so as not to be bothered by other hikers.

She was presumably a Town Bear, because she had an ear tag. This female bear was very well-behaved, from our perspective. And we had respected her space. A good encounter!

Bear stories from Anan Creek

Our two-day visit to Anan Creek south of Wrangell took place after the peak of the spawning run of pink salmon, but the waters were still black with fish on their way upstream. There was plenty of bear activity, especially in the afternoons, and the crowds of (other) tourists were much diminished by this time. So we could move around the observation platform easily, to wherever the viewing was best. We saw only black bears near the platform, but brown bears, including a female with two cubs and a lunge-feeding singleton, were regularly seen in the lagoon downstream.

Here are some of the more interesting observations:

–A small bear, probably kicked out by its mother not too long ago, came watchfully down through the boulders toward the creek. Its favorite spot was a narrow crevice between boulders, just above the water. This crevice had a front door, opening near the water, and a top door or chimney, opening through the ‘roof’. It was a big jump down to the front door, so every time this little bear came to its special place, it sat down near the chimney, dropped its little hind end through the hole, and slid down to the floor of the crevice. Then its nose would appear at the front door, as it checked for the presence of other bears and then tried to catch a fish.

It wasn’t a very effective predator on the numerous pink salmon, so it often scavenged fish remains left by other bears. Some of those remains were pretty worn out—bleached, bedraggled, ratty, and rotten. But the little guy was making some kind of living and putting on some weight.

One afternoon, a slightly larger, single bear come to the area and the two had a face-off. The little guy seemed to be dominant, and the bigger one backed away and wandered up the hill. It started to eat gray stink currants, and a few minutes later, the littler bear came up-slope and munched on another patch of currants not far away.

–A larger, very rotund bear ambled down to a streamside boulder and stood elbow deep on a rock. It was a very effective fisher, snapping up salmon in its jaws with almost every try. It captured about twenty fish in short order, and about eighty percent of those were ripe females. These females were carried about ten feet away to a regularly used ‘chomping block’. There the bear stripped out the roe (full of fat), usually also ate the brain (also very fatty), and sometimes consumed part of the back meat. The remains dropped into a convenient hole below the eating site. There they accumulated, available for other bears to winkle out, a full forearm stretch. The few male fish the bear grabbed were usually bitten in the abdomen (to make absolutely sure they were not females?) and released, either stranded on a big boulder or dropped back into the water.

A little later, an even bigger bear approached and occupied the same spot. This one just sat in the water up to its shoulders, looking around sedately. Occasionally it snapped at a fish and usually missed. Its favored method of capture seemed to be trapping a fish against a front leg with the opposite paw. This bear did not seem to forage selectively on females, in contrast to the former occupant of the boulder. It captured as many males as females, and even ate part of the males (especially the brain).

–A good-sized bear liked to hunt in a small eddy below a gigantic rock. A very effective hunter, it slowly walked up to the eddy and usually snapped up a fish in one or two tries. Flapping fish clenched in its jaws, the bear made its way to selected eating places directly below the observation platform. There it would lie, on a bed of slime and rotten fish parts, eating in peace and occasionally peering up at the human visitors through the cracks in the platform.

The best part was the route the bear chose to use for carrying its prey up to the chosen eating place. Did it use the easy path, which came up the slope gradually, around a clump of bushes? No. Instead, it came straight up a vertical route, swinging its hefty body around like a huge monkey, from one obviously well-known paw-hold on tree roots to another. And it went back down by the same route, but backwards, heaving its considerable backside around and swinging off the tree roots until it found familiar footholds, then dropping down to all fours and turning around.

–The Anan Creek observatory is well worth a visit, and it is worth staying on the platform for more than an hour or two. Permits are required during the main season of the bear activity, but they are limited in supply, so reservations need to be made well ahead of time. We rented the cabin on the shore, about a mile or so away from the observation platform, and walked up the trail each day, meeting the occasional bear. Food must be left in lockers at the cabin or the check-in point at the trailhead landing. Having been there once, I would happily go again!

Bear watching in spring

By early June, the cottonwood seed pods are fat with maturing seeds, and that’s when local bears (and porcupines) love to eat them. In some places in Juneau, many of the cottonwoods have broken-off tops and lots of missing branches on otherwise vigorous trees. That’s the result of harvesting by eager bears that commonly break off branches in order to reach the apparently delectable seed pods.

One day in very early June, I enjoyed two hours of primo bear-watching. A glossy female black bear perched high in a female cottonwood; her two tiny cubs scrambled around, beside and above her. The cubs were already very adept at climbing; they reached out to pull in small branches that held the dangling chains of seed pods, deftly stripping off the pods.

Photo by Janice Gorle

One cub clung to a slightly wobbly vertical branch at the very top of the tree. Rockabye, baby! Suddenly, mama’s big jaws chomped through the branch about two feet below the cub; with a crack and a swish, down came the tree top, cubbie and all. Cub and treetop fell ten or fifteen feet and landed safely, cushioned on a hammock of dense spruce branches well above the ground. The cub was not perturbed by the fall and immediately started to munch the seed pods from the broken-off tree top; it was later joined by its sibling.

Sometime later, the little family slid down the tree and ambled off along the hillside. A bit unsettled by some rowdy dogs that raced into the area, mama sent her cubs up another cottonwood and followed them up. Luckily, it was another female tree, so this refuge provided snacks as well.

Snacks were followed by naps: cubbies up in the tree and mama on a mossy bed among some boulders. After fifteen or twenty minutes, mama called the young ‘uns down. They gamboled up to her, in her mossy nest, and nursed for a few minutes, humming softly. Then they all departed up the hill.

Spatial overlap between bears and humans

A neutral bear encounter. Photo by

Coastal Alaska supports both black and brown bears, both of which inhabit the rainforest and potentially eat much the same kinds of food. Where they occur together, how do they get along?

In Southeast, both species occur in many areas, and one can watch both species fishing for salmon in places such as Anan Creek. Here the black bears tend to avoid the brown bears, but there are usually so many salmon that both kinds of bears feed well. But that is not always the case.

Brown bears achieve larger body size than black bears of the same age and gender. Larger body size allows brown bears to be dominant over black bears and potentially to exclude them from choice feeding areas. Salmon spawning runs are prime foraging places and brown bears are often capable of near- monopolies there. One study near Denali found that brown bears ate much more salmon than black bears, in general, and when salmon runs were poor, black bears got no salmon at all because brown bears prevented access to the streams. So in years of small salmon runs, black bears had poor body condition and poor reproduction.

Another study, on the Kenai Peninsula, also found that brown bears ate far more salmon than black bears. Occasional male black bears visited salmon runs but obtain few fish and no female black bears had access to the stream. Both species of bear ate berries extensively, but fruits made up a higher proportion of energy intake for black bears. Part of the Kenai Peninsula apparently lacks brown bears, for some reason, and in that area, black bears normally consume lots of salmon.

Although both species of bear occupy much of Southeast, there are broad areas where only one kind of bear has well-established populations. On Admiralty, Chichagof, and Baranof islands, only brown bears occur. But why, given that they co-occur with black bears in other areas? On the other hand, on the islands south of Frederick Sound, including Haida Gwaii, only black bears are found. However, fossil remains show that brown bears formerly occurred there , and brown bears are seen there upon occasion even now, but they do not establish breeding populations. Why are the browns absent in these regions? Selective hunting? Some subtle habitat change? An interesting puzzle.

Humans now occupy significant chunks of coastal Alaska, largely displacing bears from most urban and agricultural areas. Rather than deal here with the obvious issue of habitat usurpation by humans, I’d like to focus on the possible effects of hunting and bear-viewing activities. Human hunting pressure might change interactions among bears, if it is focused on one gender or if it significantly reduces bear density. In addition, we have so many bears that bear-watching has become a profitable business as well as a popular activity for local folks.

A study in south-central Alaska found that where brown bears are not hunted, males clearly dominate at most fishing sites except when fishing is poor; at good fishing sites, males were far more common than females. Big bears need to spend more time fishing to get enough fish to eat; fishing is very inefficient for them when capture rates are low. However, where bears are hunted, male brown bears were not more common than females at good fishing places. Hunting pressure is heavier on males than on females, reportedly, which would reduce their numbers. In addition, where they are pursued, males may become more wary than females, such that they sacrifice good fishing for perceived safety. Whatever the reason, fewer males meant that females, especially those with cubs, had more access to fishing sites.

Add bear-viewing humans into the mix of interactions, and researchers found that adult male brown bears tended to avoid the humans, showing more avoidance in areas where hunting pressure was higher. Males also avoided humans more when there were alternative foraging sites in the same region, but if there were no alternative sites, male tolerance of human viewers increased—and presumably females then got fewer fish.

A study in British Columbia found that females with cubs spend less time fishing when big males were active; these females had about a third less consumption of salmon than undisturbed females. Bear-viewing activity tended to displace the big males, providing mother bears with increased access to fish. Mere presence of humans had little effect on foraging of females.

Near the Mendenhall Visitor Center, most of the black bears that use the area are females and young bears; there are few adult males. Observers believe that here, too, bear-viewing humans provide smaller bears with a safe area to forage, where they are not displaced by big males. It would be interesting to learn where the adult male black bears in this region go to forage! At Pack Creek on Admiralty Island, most of the brown bears foraging on salmon in the estuary near the viewing area are females and subadults, and that the males tend to forage farther upstream, away from most humans. On Admiralty, hunting is generally harder on brown bear males than females, especially in spring, so perhaps males are rightfully more wary.

Thus, the general consensus seems to be that females avoid big males when they can and take advantage of their absence when possible, including finding temporary refuge near bear-viewing activities on humans.

Spatial overlap among bears…

Coastal Alaska supports both black and brown bears, both of which inhabit the rainforest and potentially eat much the same kinds of food. Where they occur together, how do they get along?

In Southeast, both species occur in many areas, and one can watch both species fishing for salmon in places such as Anan Creek. Here the black bears tend to avoid the brown bears, but there are usually so many salmon that both kinds of bears feed well. But that is not always the case.

Brown bears achieve larger body size than black bears of the same age and gender. Larger body size allows brown bears to be dominant over black bears and potentially to exclude them from choice feeding areas. Salmon spawning runs are prime foraging places and brown bears are often capable of near- monopolies there. One study near Denali found that brown bears ate much more salmon than black bears, in general, and when salmon runs were poor, black bears got no salmon at all because brown bears prevented access to the streams. So in years of small salmon runs, black bears had poor body condition and poor reproduction.

Another study, on the Kenai Peninsula, also found that brown bears ate far more salmon than black bears. Occasional male black bears visited salmon runs but obtain few fish and no female black bears had access to the stream. Both species of bear ate berries extensively, but fruits made up a higher proportion of energy intake for black bears. Part of the Kenai Peninsula apparently lacks brown bears, for some reason, and in that area, black bears normally consume lots of salmon.

Although both species of bear occupy much of Southeast, there are broad areas where only one kind of bear has well-established populations. On Admiralty, Chichagof, and Baranof islands, only brown bears occur. But why, given that they co-occur with black bears in other areas? On the other hand, on the islands south of Frederick Sound, including Haida Gwaii, only black bears are found. However, fossil remains show that brown bears formerly occurred there , and brown bears are seen there upon occasion even now, but they do not establish breeding populations. Why are the browns absent in these regions? Selective hunting? Some subtle habitat change? An interesting puzzle.

Brown bear in Glacier Bay. Photo by Jos Bakker

Humans now occupy significant chunks of coastal Alaska, largely displacing bears from most urban and agricultural areas. Rather than deal here with the obvious issue of habitat usurpation by humans, I’d like to focus on the possible effects of hunting and bear-viewing activities. Human hunting pressure might change interactions among bears, if it is focused on one gender or if it significantly reduces bear density. In addition, we have so many bears that bear-watching has become a profitable business as well as a popular activity for local folks.

A study in south-central Alaska found that where brown bears are not hunted, males clearly dominate at most fishing sites except when fishing is poor; at good fishing sites, males were far more common than females. Big bears need to spend more time fishing to get enough fish to eat; fishing is very inefficient for them when capture rates are low. However, where bears are hunted, male brown bears were not more common than females at good fishing places. Hunting pressure is heavier on males than on females, reportedly, which would reduce their numbers. In addition, where they are pursued, males may become more wary than females, such that they sacrifice good fishing for perceived safety. Whatever the reason, fewer males meant that females, especially those with cubs, had more access to fishing sites.

Add bear-viewing humans into the mix of interactions, and researchers found that adult male brown bears tended to avoid the humans, showing more avoidance in areas where hunting pressure was higher. Males also avoided humans more when there were alternative foraging sites in the same region, but if there were no alternative sites, male tolerance of human viewers increased—and presumably females then got fewer fish.

A study in British Columbia found that females with cubs spend less time fishing when big males were active; these females had about a third less consumption of salmon than undisturbed females. Bear-viewing activity tended to displace the big males, providing mother bears with increased access to fish. Mere presence of humans had little effect on foraging of females.

Near the Mendenhall Visitor Center, most of the black bears that use the area are females and young bears; there are few adult males. Observers believe that here, too, bear-viewing humans provide smaller bears with a safe area to forage, where they are not displaced by big males. It would be interesting to learn where the adult male black bears in this region go to forage! At Pack Creek on Admiralty Island, most of the brown bears foraging on salmon in the estuary near the viewing area are females and subadults, and that the males tend to forage farther upstream, away from most humans. On Admiralty, hunting is generally harder on brown bear males than females, especially in spring, so perhaps males are rightfully more wary.

Black bear at Mendenhall Glacier. Photo by Bob Armstrong

Thus, the general consensus seems to be that females avoid big males when they can and take advantage of their absence when possible, including finding temporary refuge near bear-viewing activities on humans.