Thursday, January 28, 2010

2008 KATMAI BEAR TRIP REPORT: PART 5 (GEOGRAPHIC HARBOUR - INDIVIDUAL BEARS)

Al (a.k.a. Scarface) - the alpha boar in Geographic during our stay in 2008.

One of the big stars of Geographic Bay was a big, heavily scarred male that we called “Al” (as in Al Pacino - Scarface). He appeared to be the dominant bear, as all other bruins in the area gave him wide berth. While we never saw any bears fighting at Geographic, the evidence of some serious combat was obvious.

A boar with a serious flesh wound. Injuries like this typically heal very quickly.

On one of our last days in Katmai, we observed a large boar with a flap of flesh peeled back from a large, open wound on its hind quarters. Every adult boar had war wounds. In most cases, these were gashes on the forelegs or wounds around the neck. One bear had a gash on its head that almost reached the eye (at first we thought the eye had been damaged). While everything seemed fairly copasetic during our stay, the area was no doubt an arena from some terrific bruin battles.

A large boar bearing wounds on the forelegs and around the neck - war wounds from intense bruin battling!

Grizzly Aggression

Stonorov and Stokes (1972) found that there were four situations in which aggression most often occurs in brown bear aggregations. They were: 1. when one bear moves too close to another bear (invades personal space) 2. when one bear loses a challenge but then redirects its aggression toward a nearby bear (displacement aggression) 3. when two bears compete for a preferred fishing site 4. when two strange bears meet.

Stonorov and Stokes describe what typically happens during an intense, aggressive encounter between two bears that are similar in social ranking. Firstly, the bears confront one another – that is, they face each other with the front legs stiffened, the heads are lowered slightly and all movements are slow and deliberate. Also, the ears are laid back, both have their mouths open to expose their canines (known as a weapons threat) and there is excess saliva production. (Bears often drool when they are stressed.)

One of two things can happen at this point – one of the bears may back down or one or both bears may charge. When charging occurs one or both bears run at each other with their heads lowered and their ears back, with mouths open slightly. If neither bear breaks off the charge and retreats at this point, the bears will come to blows. The bruins may swipe at each other with their fore paws, bite each other (usually on the neck) or lock jaws. In some cases, they bite the neck region and shake their heads violently.

When one bear has had enough, it will drop its head even lower than its opponent and begin to slowly back away (facing the winner of the battle). After putting some distance between it and the dominant combatant, the subordinate may turn and walk or run away. The dominant bear might also turn its back to the other bear and move off while still in close proximity to its opponent. This is an exhibition of winner's supreme confidence - it knows that the beaten bear will not attack again, even when the winner turns his back and makes itself more vulnerable. During combat, there will be lots of vocalizations - this is one thing that differentiates fighting from playing (the latter is a relatively quiet activity).

References:

Stonorov D. and A. W. Stokes. 1972. Social behavior of the Alaska brown bear. Int. Assoc Bear Res. & Mang. 23: 232-242.

© Scott W. Michael

BROWN BEARS: HANDLING AND INGESTING FISH PREY

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In the video featured above, you will see various fishing methods and some of the handling methods described in the article below. A few things to look for: there is a sequence of video that shows a big brown bear deftly removing the brain from a fish. There is a scarred, big boar diving into a deep river pool from the shoreline and submerging in an attempt to capture its slippery quarry (he finally succeeds in capturing a "spent" fish in the video and stands on its hind feet as it tears the fish apart). Toward the end of the video, you will see a large boar launching some of its great bulk from the river and plunging back into the water with fore legs outstretched. At one point, it has herded a big school of salmon along the river bank and appears to be trying to push some of the fish onto the shoreline. Turn up the sound and enjoy!


Grizzlies use a number of different handling techniques when feeding on salmon. In most cases, the savvy “fisherbear” will grasp its prize in its jaws and carry it from the waterway to the shore, a gravel bar or surrounding grassy meadow/woodland (subordinate grizzlies, in the presence of conspecifics, are often more likely to move farther from the capture site than larger, more dominant bears). They then place their catch on the ground and stand on it with the fore paws. How the prey fish is processed may vary from one individual bear to the next or from one location to another. In many cases the first thing a bear will do is bite down on the posterior region of the fish and remove the tail section. Another body tissue targeted early in the handling process is the skin. To skin its quarry, the bear will grasp the skin with the incisors and pull upward, peeling the integument from the salmon’s body.

If food is in short supply (e.g., it is early in the salmon run or if fish numbers are down) the bear will consume the entire fish. If food is abundant, the bruin may select the choicest parts of the fish and leave much of its behind for scavenging birds, other mammals or even other bears (e.g., subordinate individuals or those that are poor at fishing). As mentioned in other posts, the skin is preferred as are the brains, but rather than ingesting the entire head, the bear often bites through the top of the cranium and laps out the brain or plucks them out with its incisors (see video footage above).

Not all bears take the time to leave the stream to eat their prize. It is not uncommon to see a bear, standing in knee deep water, clamping the fish against the front foreleg with the opposite paw (some bears employ this technique when eating fish on shore). The bear then rips the fish apart, one bite at a time. If the water where a fish is captured is shallow enough, some bears will pin the fish to the stream bed, while in a state of repose, and then stick their head underwater and rip pieces from their piscine prize (the bear will raise its head to masticate and then submerge to take another bite).

I have noticed that in many cases the fish rarely struggle much after being trapped in the bear’s jaws. They seem to go limp. They may flop about if the bear should drop them on the shore before pinning them down to eat, but otherwise they resist very little while in the jaws of the bruin. (I did see occasions where they fish would struggle if a bear bit down on the upper back.)

© Scott W. Michael

2008 KATMAI BEAR TRIP REPORT: PART 4 (GEOGRAPHIC HARBOUR - INDIVIDUAL BEARS)

A sow with her older cubs attempts to teach them to fish, although they prefer to play and loot their mother's catch.

Geographic Habor’s fishing grounds were also home to a vivacious family unit, consisting of a sow and a pair of ~ 2 1/2 year olds. The mother was an efficacious “fisherbear,” while her cubs did little fishing. Instead, they spent much of their time grappling with each other like hairy Sumo wrestlers! When they were not playing, they were shadowing their mom and stealing any fish that she hauled in. Most of the time she would let them take off with her catch, although she did occasionally attempt to wolf down some of her piscine prey before she was looted by her greedy brood. On one occasion she lost her patience and cuffed one of her overzealous offspring before giving in and letting go of her fish (see video below). Occasionally, the two hooligans attempted to include mom in their frolicsome behavior. She complied a couple of times, jawing at her young assailants.

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A trio of grizzlies: a sow with her two offspring (these to youngsters are probably 32 months old). Note how she does all of the fishing, while they benefit from the fruits of her labor! Compare these two laggards with the adolescent fishing machine below.

In contrast to these impish, 2.5-year olds, we observed an amazing young bear that was a fishing machine! This bruin was a ~ 1.5 year old (usually referred to as a yearling) with a light colored (nearly blonde) mother. The pair initially made their presence known when the mother, with the cub trailing behind, were observed chasing another bear. They gave up their half-hearted chase and began to slowly meander toward the prime fishing area. Once they arrived at the river bank, it was not long before the yearling was chasing and even catching salmon! (There were few other bears in the area at the time.) The mother bear seemed to lag behind the young bear, keeping close enough to protect its progeny if the need arised, but yet far enough away to allow it to learn some life skills. The young bear was such an enthusiastic piscator that at one point it had a fish in its mouth, while it attempted to capture a second salmonid (see the video below)!

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The fishing exploits of an ~ 1.5-year old (yearling) bear - this young bruin was a very effective fisherman, as you will see in the video above.

© Scott W. Michael

2008 KATMAI BEAR TRIP REPORT: PART 3 (GEOGRAPHIC HARBOUR - INDIVIDUAL BEARS)

A sow with a first (spring) cub. Bother were very flighty. At one point, the cub ran into the tall grass and it took the nervous mother 20 to 30 seconds to relocate her progeny.

During our stay at Geographic Harbour, we spotted one sow with a first year (spring) cub, both of which were quite flighty. The sow had large, white fringed ears and her cub looked very healthy (it was quite chubby!). The first time we saw them, they made a brief appearance at the river when four or five other big bears were around. Their stay was brief, being cut short when the nervous cub was startled and dashed into the tall grass. Mother gave chase and after 20 to 30 anxious seconds was able to relocate her frightened offspring. The pair disappeared after that, apparently in search of safer pastures in which to feed.

On our last day at Katmai, this sow and her cub reappeared. The mother’s desire to increase her nutrient intake apparently overcame her concern about exposing her cub to conspecifics. The mother succeeded in catching a few fish, with the cub trailing right behind her (this includes venturing into the rapid moving water in the center of the stream). The cub also ate some its mother’s catch. It is sad to think that this tubby little bear has about a 40 % chance of surviving to adulthood.

Ginger Bear - a young bear, possibly chased off early from its mother. This is one of many pink salmon this little bear was able to capture.

On our second day at Geographic, we observed a small bear that cautiously made its way to the river. It appeared to be a young bear – possibly a runty three-year old. We speculated that it may have been run off by its mother prematurely or possibly it had somehow lost its maternal parent? It came to the river to fish and was successful in its efforts. Rather than eating it near the stream bank, the little bear grabbed its salmon by the tail and sought solitude in the tall grass. When fishing, it was very aware of its larger ursid neighbors, no doubt cognizant of its greater vulnerability because of its small size. This bear had a very distinct appearance – it was rather skinny and had large ears (it almost had a fox-like look about it). We dubbed it Ginger Bear because of its lighter pelage. We were to encounter ginger bear on a couple of occasions (more on this bear later).

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2008 KATMAI TRIP REPORT: PART 2 (GEOGRAPHIC HARBOUR)

Geographic Harbour (Amalik Bay) is picturesque, sheltered and infested with brown bears!

On previous trips to Katmai, most of our bear-viewing had taken place at Hallo and Kukak Bays. On our 2008 trip, we didn’t get to either of these sites as bear numbers were sparse at the time. Instead, we spent much of our adventure in Geographic Harbour, a picturesque site at the head of Amalik Bay. Like the rest of Katmai, the scenery is magnificent and bears are ubiquitous - there are usually at least two or three bears fishing in the main stream that flows into the bay. The harbour is surrounded by a high profile landscape that provides natural protection from the inclement weather that rushes across the Gulf of Alaska. It provides an ideal anchorage and a calm landing “strip” for float planes.

The downside of Geographic, is that on a clear day you are likely to share the prime bear-viewing spots with a number of “day-trippers” (these bear-viewers arrive by floatplane and remain in Geographic for two to four hours before being whisked back to Homer or Kodiak). During our stay, there were times where we were in close proximity to at least 30 other bear-viewers. While it certainly takes away some of the “wilderness feel” of the experience, this “bear paparazzi” did not seem to bother the bears that frequent Geographic Harbour (mind you, there may be other bears that would come and fish here but do not while the viewers are present). Also, in the early mornings and from mid-afternoon on, we were the only people among the bears.

A rotund sow (possibly a barren female - see notes in text below) exhibiting the typical Geographic Harbour dark pelage.

Interestingly enough, the bears that frequent Geographic Harbour tend to be darker in color than their Hallo Bay “cousins.” While you see some darker bears in Hallo, almost all the bears at Geographic are chocolate brown. While I am sure it varies from year to year, there were fewer bears at any one time on the Geographic stream than we had seen in early to mid-August at Hallo (we saw as many as 23 bears at once during one of our previous Hallo Bay visits, while the most Ursus arctos in view at any one time in Geographic was less than 10). This may be due to the fact that the prime fishing spots (at least those in view of the bear-viewing areas) in Geographic are not as abundant so there is less space for bears to fish comfortably around one another (fishing spots are more abundant when the tide is out).

In Geographic, there is high grass meadow (Calamagrostis spp.) that grows right up to the edge of some portions of the river. It was not uncommon to see subordinate bears, standing on their back legs, peering above the grass to make sure it was safe to take up a position along the water way. At low tide we would take-up a station on the intertidal flats, where bears fished in the dendritic tributaries that branched out from the main river channel. There is also a viewing pad, consisting of a flat, slightly raised bank situated along the edge of the stream that can be used at both low and high tide. It was not uncommon for bears working the stream edge to come within 15 to 20 feet of this viewing area.

While the area was never overrun with bears, there was often good fishing action in Geographic, especially at and around low tide. We saw numerous salmon pulled from the water by subadults, and both adult boars and sows (although the latter were slightly more abundant in the area). There were some fat, beautiful sows around the river, several of which were very effective at catching fish. One of these females was huge! Brad Josephs, brown bear expert, speculated that this was possibly a barren female, as they have a propensity to become very rotund.

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2008 KATMAI BEAR TRIP REPORT: PART 1

In late August of 2008, Janine and I were joined by five other photographers/naturalists on a trip to Katmai National Park. This included Larry Jackson, Debbie Titus, David Salmanowitz, and Larry and Nancy Peterson*. I had been to Katmai in 2006 and 2007 and was excited to get back, as well as share this very special place with great friends. Based on their reactions, I think they too have caught the bear bug - at least three of the five have expressed an interest to go back next year!

We were the guests of bear-viewing guru John Rogers (Katmai Coastal Bear Tours). He runs a number of boats along the Katmai coast and he, and his guides, know the area and the bears like no one else. I had been with John on my two previous trips and once again, John and company came through with a truly amazing wildlife experience!

Katmai Notes

In my past two visits to Katmai, I did my bear-viewing in early to mid-August. This year, we arrived in the land of the great bear a little later in the season (from August 22 until August 31st). We hoped to see more corpulent bears (as a result of a few more weeks at the “salmon buffet,” which is available from July into September) as well as some different behaviors. It was highly likely there would be more fishing activity as at least three and possibly four species of salmon (chum, pink, sockeye, and possibly silver) could be “running” at that time. I also wanted to document bears feeding on moribund and/or dying salmon, as this food source is an important part of the diet of hyperphagic bears.

It turned out the fish were present in large numbers. In fact, in certain parts of the Alaskan Peninsula (e.g., Bristol Bay), there were reports of huge fish runs. I certainly observed bears catching more fish during this trip than I had seen on previous visits (in the past two years I had seen relatively small runs when I visited). We observed pink (Oncorhynchus gorbuscha), chum (O. keta) and sock-eye salmon (O. nerka) being plucked from Katmai’s rivulets. While there were definitely more fish, we saw fewer bears than we had on our past trips. Some locals speculated that the reduction in fishing bear numbers was a function of an abundant berry crop – many of the bears were in the ”bush” gorging on salmon berries. Even though Ursus arctos numbers were down, there were still more than enough bears to keep us in a constant state of awe.

First Stop Kodiak

We began our trip in Kodiak – the jumping off site to Katmai (i.e., you take a float plane from Kodiak to the Katmai coast to meet the “bear boat”). We arrived at Kodiak about five days before our Katmai trip was to commence. Katmai Coastal Bear Tours recommends that you show-up in Kodiak at least a couple days before your scheduled departure, just in case it is necessary to make an early trip to Katmai. If inclement weather is forecast for the day you are scheduled to travel to Katmai, John may have you fly out to the boat one or even two days earlier in an attempt to ensure you get to spend the time you paid for with the bears.

Spending some time on Kodiak is a treat in and of itself! It is one of the most beautiful places I have ever seen, especially when viewed from the air. There are valleys, mountains, rocky coastlines replete with tide pools, clear streams and lakes and lush vegetation (the latter is a function of the high precipitation levels [average annual rainfall of 173 cm, average snowfall 198 cm]). And, of course, it also has a large population of brown bears (a.k.a. Kodiak bears). How many Comfort Inns in the world have a sign posted on the door suggesting that guests be very careful while moving about the parking lot after dark as a curious bear has been sighted lurking around the hotel! During our stay, there were a couple reports of Kodiak bear being sighted fishing in local streams. While we did not see any bears on Kodiak, we did visit a beached humpback whale carcass in hopes of seeing some scavenging brown bears. We also did lots of hiking, learned about spatterdock (Nuphar luteu) (thanks to Larry, our amateur botanist), enjoyed some amazing scenery and found some great intertidal, invertebrate life.

Fortunately, the weather was good while we were on the island (although we arrived on a blustery, rainy night) and we were able to get off to Katmai on schedule. In the next post, we will take a look at our first bear-viewing stop, Geographic Harbour.

URSIDOPHILES 2008

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* Larry and David are great dive buddies and accomplished photographers - Janine and I have spent many hours with them in the Western Pacific, both above and below the water! This was the first time we had traveled with Debbie - she was a delight to have on the trip and an accomplished photographer in her own right. Larry and Nancy are good friends from Lincoln, Nebraska (where we reside) that are passionate about wildlife. We want to thank these five great travel companions for sharing this wonderful ursid-rich experience with us!

© Scott W. Michael

MARINE MAMMALS ON THE MENU

A veritable brown bear buffet! Photo taken by Scott W. Michael.

It looked like a big, white amorphous blob at first glance, but after further investigation one could make out the mouth-end of the beast, the flukes and flippers. It was a humpback whale that had washed up on the shore of Fort Abercrombie State Historical Park, Kodiak (Alaska) about a week before we searched it out. We had heard reports that the whale had been deposited by winds and waves on the Kodiak coast, but finding the rotting blubber-laden beast was to prove a bit of a challenge. When we visited the local rangers station, they didn’t seem too eager to tell us where it was. After further probing, they finally shared the approximate location. As we left the office, a ranger mumbled “Watch out for bears.” We concluded this is why they were hesitant to share the cetacean’s resting place - they did not want to have to deal with a problems that can occur when people and food hoarding bears cross-paths.

It turns out that dead whales are a favorite of coastal brown bears in parts of coastal and insular Alaska. The tons of rotting blubber, flesh and whale organs can produce an olfactory beacon that can reach the nasal epithelium of a brown bear many miles away (there are anecdotal accounts of bears smelling putrid whale from 20 miles away). The culinary tastes of a brown bear are not that refined, and besides whale flesh has lots of nutrients that can help a bear lay down fat for the denning period. The only drawback to eating a dead whale is the flesh can be hard to handle. The skin is so tough that even a massive brown bear can have a difficult time tearing a chunk free and masticating it. (The blubber layer of a whale’s flesh can be as thick as 43 to 50 cm!)

A whale carcass can attract many bears, as was the case on the California coast centuries ago. In the book “California Grizzly” (1955) the authors share the following:

Those (ed. grizzly bears) living near the seacoast were attracted to the bonanza supply where ever a whale washed ashore – and the one-time abundance of whales in our coastal waters probably made this a not uncommon event. The first reports of bears eating this food was by the VizcaĆ­no party at Monterey in 1602; a very large whale had gone ashore, “ and the bears came by night to dine on it” (Wagner, 1929). Revere (1849) wrote that the carcass of a whale, thrown upon the beach, will attract a “regiment of bears” – and Kotzebue (1921) used the term countless “troops.”

On the shores of Kodiak Island and along the Katmai coast, groups of brown bears feed on moribund whales, while on the Kenai Peninsula, bears of various age classes are reported to move to Bristol Bay to scavenge on dead gray whale (Eschrichtius robustus) (Glenn and Miller, 1980). In the Yukon, grizzly bears have been observed to scavenging on Beluga (Delphinapterus leucas) carcasses. Troyer (2005) reports seeing 12 bears feeding on a gray whale carcass at the same time (there were 18 bears in the immediate vicinity). He states that all of the bears worked over the carcass, only occasionally engaging in brief altercations during the feast. Some bears would leave, only to have their place taken over by another bear. Bear continued feeding on it for a week, at which time the remains of the carcass were carried away by the tide. There are reports of observers seeing brown bears entering or appearing from a hole in a large whale carcass. Apparently, the bears entered the bloated whale to feed on the internal organs or chew at the muscle from the inside. After gorging themselves with whale flesh, brown bears may roll on the odoriferous carcass. The function of this behavior (which, unfortunately, is also a habit they share in common in domestic canines) is not known.

Brown bears occasionally capture live pinnipeds, like these harbor seals. Photo by Scott W. Michael

Not only are moribund marine mammals consumed, brown bears have actually been known to captured and kill pinnipeds. Of course, polar bears are well known form their seal-eating habits. They have developed hunting strategies and physical adaptations to effectively exploit this resource. Grizzlies, on the other hand, feed on these animal opportunistically. If a hungry bear encounters a hauled out seal that it can get to before the latter can reach the water, it may attempt to subdue it. For example, grizzlies have been known to eat harbor seals (Phoca vitulina) along the Alaskan Peninsula and in the Northwest Territories of Canada. They are more susceptible to bear attack than some other pinnipeds (e.g., sea lions) because they are much more cumbersome and would have a more difficult time escaping if they are too far from the water’s edge. Seals are also more likely to be found along sandy shorelines, where bears sometimes hunt. That said, in most cases, seals haul out on small islets along the shore – habitats that are not often visited by grizzlies. There are also rare reports of big coastal brown bears taking on walruses (this has been reported on the Kenai Peninsula) (Glenn and Miller, 1980).

(Unfortunately, it turned out we never did encounter any bears on the Fort Abercrombie humpback carcasses the day we visited it, but I would not be surprised if it was eventually located and fed upon by opportunistic brown bears.)

References:

Glenn, L. P. and L. H. Miller. 1980. Seasonal movements of an Alaska Peninsula brown bear population. Int. Conf. Bear Res. And Manage. 4:307-312.

Check out these videos of brown bears feeding on dead whales:

A group of brown bears feeding on a whale carcass on coast of Kodiak Island, includes wallowing on dead cetacean (please pardon the silly commentary). Click here.

© Scott W. Michael