Brooks River

Brooks River Bears Need Your Help

/ Mike Fitz / 18 Comments
two sleeping bear cubs

402’s spring cubs rest near the Lower River Platform at Brooks River on October 24, 2013.

Addendum: Please read the response to this issue by Katmai’s Superintendent, Mark Sturm.

In 2017, an elevated bridge and boardwalk will be constructed at Brooks River. In this post, you’ll find a letter that asks Katmai National Park to further restrict the timing of staging and construction for the bridge. My reasoning is outlined in the letter. I wrote it because I believe no staging or work on the project should happen from late June to late July or September and October. Brooks River’s bears, especially those who are not habituated to people, need complete access to the lower river area in the fall. That is their last chance to gain weight before hibernation. The current work schedule allows staging and work to begin when bears need Brooks River most. This is not acceptable.

You are welcome to use the letter to contact the park. You can use it as is, or personalize it as you see fit. You can copy the letter’s text below or download the rich text file which can be used with almost all word processing software.

Before you contact Katmai with your thoughts, please consider the following…

  • The construction dates for the bridge project are in a federal contract which has already been awarded. If the dates can be modified it won’t be a simple process since it’s currently a contractual obligation. Don’t expect any change, if it comes, to be quick.
  • Form letters are easy to respond to, because the recipient only needs to write one response. Personalized messages often require more in-depth responses.
  • Phone calls can be more effective than written correspondence.
  • Be polite and respectful when you contact the park. The people who manage Katmai are intelligent and well-meaning. They do not deserve insults or personal attacks.

You can contact the park in several ways.

And now the letter:

Superintendent Sturm,

As you know, an elevated bridge and boardwalk will be constructed at Brooks River in 2017. The summary of work outlined in the project’s construction specifications generally restricts work and staging of equipment and supplies outside of July. Yet, it places minimal restrictions on staging and construction in late summer and fall. This will have serious impacts on bears who need full access to the river in September and October. I urge you to reconsider the construction schedule and modify the current contract to minimize the project’s impact on bears.

The construction schedule allows work in the river corridor to commence as soon as October 1. Work hours outlined in the construction specifications also permits staging on the spit at the mouth of Brooks River anytime after August 1. These activities can potentially displace many bears from the lower river, especially those who are not human-habituated.

Dozens of brown bears gather at Brooks River throughout September and October. The fall feeding period is especially critical, since bears are hyperphagic and need access to Brooks River’s abundant salmon. The river mouth provides salmon catch rates far higher than other areas of the river. Additionally, many bears who use the river in the fall are not habituated to people or vehicles. Habitat use by these bears is already restricted by the presence of people. Staging and construction in the fall will further displace these animals. Impacts to wildlife and the visitor experience from staging and construction of the bridge is of short duration, but can potentially be serious for individual bears who need to utilize the river. Bears that feed at Brooks River may do so because they know of no other or better place. For them, salmon in Brooks River ensures their yearly survival.

I understand that water levels in Naknek Lake provide a narrow window to transport materials and supplies to Brooks River, and often this can only occur in mid to late summer. However, this does not justify displacing bears from the food resources they need to survive, even for one season. Brooks River is a world famous bear viewing area. In FY16, the bearcams received 40 million hits. Brooks River’s wildlife deserves the highest level of protection possible. To do this, I urge you to place further restrictions on the construction schedule for the elevated bridge at Brooks River. Staging should only occur outside of July and September-October. Construction and clearing work in the river corridor should begin no sooner than November 1.

I look forward to your response and thank you for your time.

Addendum: Please read the response to this issue by Katmai’s Superintendent, Mark Sturm.

Bears Have Long Memories

/ Mike Fitz / 12 Comments

Mother bear standing on rock. Her cub sits on the rock between her legs.Bear cubs are apt to reflect mom’s mood. When she’s relaxed, they are relaxed. When mom is alert and stressed, her cubs are on edge. Cubs also take a keen interest in anything that their mother investigates. In this way, they learn much about what to eat, where to find food, and many other survival skills. In this way, mother bears are teachers. However, mother bears may teach their cubs behaviors that lead to conflict with humans.

In a study recently published in the journal PLOS One, researchers from the University of Alberta found that behavior that leads to conflict with humans is not genetic. It is learned. Bears who were raised by mothers with a documented pattern of conflict with humans were more likely to be involved in conflict with humans as adult bears. The study identified 213 bears (118 males and 95 females) through DNA extracted from hair samples, then examined behavioral patterns in both father-offspring and mother-offspring relationships. The researchers concluded over 60% of offspring from “problem mothers” were likely to be “problem bears.”* In contrast, only 29% of bears from “problem fathers” were identified in bear-human conflicts. This was very similar to the percent of bears (30%) involved in bear-human conflict raised by mothers with no history of conflict with people. Since male bears have no role in raising cubs, the evidence in the study suggests that behavior leading to conflict with people is learned, not inherited through genes.

Behavior of offspring was not related to the behavior of the father bear. http://dx.doi.org/10.1371/journal.pone.0165425.g002
Bears raised by mothers with a history of bear-human conflict have a higher likelihood of conflict with people. http://dx.doi.org/10.1371/journal.pone.0165425.g002

If you watch Katmai’s bearcams, you may be familiar with the escapades of 273 and her cub. These bears are famous for their curious and playful nature. Over the past two summers, they were prone to investigate almost anything that caught their attention. In 2015, they damaged buildings at Brooks Camp which prompted rangers to escalate their hazing techniques to deter them.

Tar paper shack surrounded by portable electric fence.

This building was damaged by 273 and cub in August 2015. I helped to erect the electric fence as a temporary deterrent to further damage.

They repeatedly damaged a sign near the bridge over Brooks River.

They caused wildlife technicians to photo-bomb a live chat on archeology.

They even played with unattended construction equipment.

I took the video of 273 and her cub with the construction equipment from inside a cabin last summer. Clearly, this family has demonstrated an interest in human objects and equipment. They are also relatively habituated to the presence of people. Since 273 has exposed her cub to people and buildings, does this increase the likelihood that the cub will repeat those behaviors when he becomes an independent bear? All signs point to yes.

I’ve long suspected that bears raised by highly human-habituated mothers are more likely to demonstrate high levels of habituation toward humans when they are adults. I’ve also suspected the same with bear-human conflict. If mom teaches her cubs to investigate human equipment or seek out human food, then the cubs are going to remember those experiences when they become independent bears. The study from Alberta provides some evidence to support my suspicions.

Does this mean that 273’s cub is destined to damage property at Brooks Camp? Not necessarily as long as rangers, lodge staff, and visitors at Brooks Camp are vigilant and actively work to eliminate conflict between bears and people. (Access to lots of natural food is extremely important too.)

Mother bears are teachers and cubs are students, but not everything cubs learn from mothers is advantageous in a world where habitat is increasingly crowded with people. Mother bears teach their cubs many survival skills, some of which can lead to conflict with humans. We can’t change the way bears live, nor should we. The onus is on us to act in ways that allow bears space to live and survive without learning behaviors that lead to conflict.

——-

*I discourage the use of “problem bears” as a term to describe bears involved in bear-human conflict. The term was used in the study, but this label stigmatizes bears in negative, anthropomorphic ways. These bears are only exploiting opportunities presented to them. The problem isn’t the bear. The problem is the temptations for conflict provided or caused by people.

Brown Bear Fatness Index

/ Mike Fitz / 6 Comments

Brown bears get fat, often really fat. They also lose a lot of weight and sometimes become really skinny. They are often fat and skinny in the same year. When you watch brown bears, either in person or via bearcam, you can sometimes make a fairly accurate determination of a bear’s body fat and relative health by looking at its shape.

Fatness can be used as an indicator of health in brown bears. Brown bears need to eat a year’s worth of food in six months or less to survive, and body fat is the key their survival. They can lose 30% or more of their body weight during hibernation and can continue to lose weight throughout the spring when few high calorie foods are available. In the Brooks River area, only after green plants begin to grow and salmon have arrived do most bears begin to regain lost weight and start to accumulate body fat.

While fat is important to bears, a thin bear isn’t necessarily an unhealthy bear. Young subadult bears and yearling cubs, for example, often appear thin in spring and early summer before many high calorie food sources are available. These bears usually regain lost body mass in summer and early fall.

Polar Bear International developed a handy scorecard to measure the relative fatness of polar bears. I’ve adapted it for brown bears. My brown bear fat index uses the same categories as the polar bear index, which ranges from skinny/emaciated to very fat/obese. I also included additional information for each category such as the age/sex class most likely to be in a category and the time of year bears are most likely to be in a category.

Please note, my brown bear index is subjective and based on my observations at Brooks River, Katmai National Park, Alaska. The polar bear fatness index is also subjective, but less so than mine because researchers who handle immobilized bears can palpate the animal to estimate its body fat content. (Katmai’s Changing Tides project also tracks body fat content in female brown bears, but uses bioelectric impedence analysis.)

Brown Bear Fatness Index

Emaciated: bear appears skinny with ribs, vertebrae, and hip bones usually clearly visible unless covered by fur.

  • Time of year most likely to happen: late winter through early summer, but can happen in all seasons.
  • Age/sex Class: Older bears, especially older mothers with newborn cubs and injured bears
emaciated 16 Cinnamon.jpg

16 Cinnamon shows an emaciated figure in July 2010. Notice his prominent hip bones and shoulder blades. If he had less fur, his ribs would also be noticeable.

emaciated 16 Cinnamon_2.jpg

In this photo, also from July 2010, Cinnamon’s vertebrae seem visible through his fur. Despite his lack of body fat in July, he survived winter and returned to Brooks in 2011. At the time, he was estimated to be at least in his late 20s, but could’ve been older.

Thin: vertebrae and hip bones partly visible; narrow body

  • Time of year most likely to happen: late winter through early summer, but can happen in all seasons.
  • Age/sex class: subadults, yearling cubs, 2.5 year-old cubs, older bears, and mothers with newborn cubs
thin 234 Evander fishing near the far pool 2.jpg

234 Evander in July 2010 displays a thin body with noticeable hip bones. Evander was an older bear (probably older than 20 years) in 2010.

thin 503.JPG

In this photo from early July 2016, 503 Cubadult appears thin with slightly visible hip bones. His narrow body shape is not uncommon for young subadult bears (he was 3.5 years old in July 2016), and does not necessarily indicate poor health. Rather it reflects the time of year and his low rank in the bear hierarchy.

Average: hip bones and ribs not visible; the bear’s body, neck, and head are evenly proportioned

  • Time of year most likely to happen: all year, but most often summer
  • Age/sex class: all ages
average 505.JPG

This adult female, 505, is well proportioned and a good representative of average fatness for an early to mid summer bear. Photo taken on July 8, 2016.

Fat: fat over rump, stomach hangs low; bear’s neck is semi-fat but doesn’t distort the size of the head

  • Time of year most likely to happen: late summer and fall
  • Age/sex class: adult males in prime of life in mid summer, all bears late summer and fall
Fat 89 Backpack_03_09132015.JPG

Katmai’s brown bears most often reach the fat class in late summer and fall when salmon are readily accessible and have been so for two months or more. In this photo from September 2015, 89 Backpack displays the typical body shape of a fat bear. Most bears attain this body shape before they hibernate.

fat 747.JPG

Sometimes large adult males, like 747, can reach the fat category by the end of July. Some bears aren’t this fat when the go into the den, yet 747 reached this size months before hibernation. This photo was taken in late July 2015.

Obese: stomach hangs very low; bear’s neck is very fat and makes head appear smaller in proportion to its body

  • Time of year most likely to happen: very late summer and fall
  • Age/sex class: adult males in prime of life and adult females without cubs
Obese 747.jpg

This NPS photo of 747 epitomizes an obese bear. (He should’ve won #FatBearWeek. Election was rigged!) Seriously, this is an extremely obese bear. I don’t think I’ve ever seen a bear this fat before. His belly hangs nearly to the ground (the water is not very deep where he stands in the photo). 747 is a very dominant adult male at Brooks Falls. As such, he has access to his choice of fishing spots. His well-endowed figure is proof of his dominance, health, and fishing skills.

Obese 409 Beadnose_45_09232015.JPG

409 Beadnose shows the ample proportions of an obese female in September 2015. Females with cubs do not usually attain this level of fatness because of the energetic costs associated with raising cubs. Beadnose did not have cubs in 2015.

Strut Your Stuff

/ Mike Fitz / 12 Comments

In my last post, I broke down an interaction between two mother bears, one of whom was particularly defensive. Bears though don’t always charge and threaten violence to make their point. As this video illustrates, bears communicate through body language to establish dominance and avoid conflict. (Warning: Long Video.)

In the video, 747 is the heftier, darker bear. 68 is the tall, lanky bear. Both are mature adult males, likely in the prime of their lives. As I see it, bear 747 comes out of this on top as he asserts his dominance over the newcomer, 68. This took some time, however. 68 didn’t exactly yield like most would upon the approach of 747.

As the video starts, 747 (left) immediately approaches the newcomer on the island. 68 subtly skirts 747, but continues his approach toward the falls. You can see that 747 is much bulkier than the newcomer, but the new bear is just as tall, if not taller.

Screen Shot 2016-10-14 at 10.49.25 AM.png

747 (left) approaches 68 on the island downstream of Brooks Falls.

When 747 turns his back on the new bear, 68 takes the opportunity to mark some grass (0:50). 68 is not acting submissive or yielding.

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After a brief do-si-do, 68 (left) marks grass while 747 does the same.

The new bear approaches 747. 747 stands and watches. At this point, the outcome is very much undecided (1:12).

Screen Shot 2016-10-14 at 10.51.34 AM.png

68 (left) approaches 747.

After a little more posturing, 747 turns to mark the willow on the island. This is a bold display of dominance in front of 68. The newcomer though continues to cowboy walk away from 747, still not submissive but very focused on 747’s movements (2:00).

Screen Shot 2016-10-14 at 10.52.50 AM.png

747 marks a willow tree while 68 postures nearby.

747 follows the exact same route on the island as 68, probably following the newcomer’s scent and leaving his own on the way (2:20). 68 postures more in the grass. 747 again marks the tree. This time for almost 30 seconds (3:18).

Screen Shot 2016-10-14 at 10.53.28 AM.png

747 says, “This is my turf.”

747 then goes to the grass where 68 just was and rubs it on his body. He seems to want to leave a scent trail everywhere his competitor has (4:05).

Screen Shot 2016-10-14 at 10.53.59 AM.png

747 (center) marks the grass where 68 had just walked.

68 walks downriver. 747 follows. In the riffles, 747 catches up to him. Instead of fighting, the bears posture more. Here’s where 747 seems to assert his dominance more clearly. 68, instead of posturing further, stands in the riffles and watches 747 approach then walk away (5:00).

Screen Shot 2016-10-14 at 10.54.21 AM.png

747 pursues 68 downstream.

The video cuts to a moment a few minutes later when 68 makes his way back to the island. This draws 747’s attention and he approaches 68 again. 747’s ears remain upright and forward, a sign of dominance in this context. The new bear’s ears are oriented back against his head, a sign of defensiveness (6:40).

Screen Shot 2016-10-14 at 10.55.34 AM.png

747 (left) directly approaches 68 one last time. Note the bears’ ears. 747’s are pitched forward like he is not intimidated by 68.

747 circles 68. 747 walks away and the newcomer stands and watches, indicating that 747 successfully asserted his dominance in the interaction. 747 then goes back to the island and marks the vegetation again (7:05). 68 continues to stand and watch. Winner: 747.

747_06272016.JPG

747 is one of the largest and most dominant bears at Brooks River.

During encounters between adult male bears, the “winner” is the bear who ends the interaction, usually by walking away. This is exactly what 747 did. (Exceptions are when bears compete over a resource they want like food, a fishing spot, or access to a female. In those cases, the dominant bear stays where he wants, displacing the subordinate bear who usually moves away.)

Any time a new bear arrives at Brooks Falls, my interest piques. Newcomers are often wildcards. They may or may not know how to fish the falls and must weave their way into the river’s hierarchy. 68 was never identified at Brooks Falls in July. I didn’t recognize him when he arrived. He seemed to show some familiarity with the falls area and wasn’t particularly wary of other bears. When 747 saw the newcomer I thought, “This could get interesting.” It did, just in a non-violent way.

68 and 747 communicated their intentions clearly through posturing and marking vegetation. Throughout the entire video, these bears get very close to each other, but never make physical contact. Both want to hold high places in the hierarchy, because dominance confers many advantages. Through a continued, confident approach and more exaggerated posturing, 747 asserts his dominance over the newcomer. This is a classic, albeit lengthy, example of bears using body language to communicate their intentions, avoid physical conflict, and establish dominance.

For more information on Katmai’s bears, download the latest edition of Bears of Brooks River: A Guide to Their Identification, Lives, Identification, and Habits.

When Mother Bears Collide

/ Mike Fitz / 39 Comments

What happens when two mother bears, both with spring cubs, meet?

Defensiveness is a trait of all mother bears. In the video, 128 Grazer is the blonde bear with three spring cubs, and her defensiveness is immediately evident. She jaw pops and salivates as 409 approaches.

Mother bear standing near cubs at base of a tree.

128 Grazer stands next to her cubs. Her excessive salivation is a sign of stress.

Meanwhile, 409 shows no signs of aggression. She probably just wants to get to the river and fish. Her two cubs are behind her.

Bear standing in grass.

409 Beadnose stands the in grass right before Grazer charges.

128 charges 409. If you listen carefully, you can hear one or both bears utter a low bellow.

Two bears with open mouths in grass.

Beadnose (left) and Grazer (right) face off as Grazer stops her charge just short of contact.

409 stands her ground (unlike an adult male who encountered a charging 128) likely because she’s protecting her cubs too. 409’s cubs climb separate birch trees. Now both sets of cubs are up trees. The mother bears can’t go far in this situation.

Bears in grass with cubs in trees.

Beadnose and Grazer face one another while their cubs remain in nearby trees.

The situation de-escalates quickly, which is not uncommon in encounters between bears. 128 then moves back to the tree holding her cubs. Beadnose slowly approaches the river then turns toward her cubs, almost like nothing happened. Both mothers keep watchful eyes on the other.

bears standing at the edge of a waterfall

409 Beadnose (left) stands near 128 Grazer on the lip of Brooks Falls in 2015.

Last year, these bears were extremely tolerant of each other. Cubs change the dynamic though. As a new mother, 128 behaved particularly defensive around bears and people in late June and early July. Beadnose’s relatively calm disposition may reflect her greater experience raising cubs (this is her fourth litter) and her high tolerance for certain bears like Grazer. Perhaps Grazer’s aggression is a product of her inexperience. This is her first known litter.

The bears’ experience and disposition factored into the interaction. Each encounter between bears (and bears and people, for that matter) is unique. Defensiveness is one possible reaction when mother bears collide.