Infanticide: An Ugly Side of Nature

Bears are beautiful to me.   I spend a lot of time around them and enjoy learning about them by watching their behavior and studying research on bears.  Over time my attitude towards bears has moved from fear of them to respect of them.  This is especially true for mother bears.  Mother bears perform all the work (birthing, feeding, protection of their cubs, and hibernating with their cubs).  Male bears search for females to mate with, eat, sleep, hibernate alone, and fight with other bears.  Witnessing infanticide of a bear cub was a behavior I wished never to see.

Adult bears are also known to kill bear cubs, including cubs from the female they impregnated. This uglier side of nature, infanticide, the killing of baby bears by an adult (usually male) bear, is something I never wished to witness.  In past years at Katmai National Park, I watched a couple of close calls where an adult tried to kill a cub.

Well, infanticide does indeed exist in nature and this past July I, unfortunately, witnessed a large male bear kill a cub, and then brutally attack the mother of the cub when she tried to intervene.  Infanticide does end up with the mother also being killed in some cases.

Why Do Adult Bears Kill Cubs?

There is no one simple answer to this tough question.  Research and observations currently consider three motivations for this behavior.

  1. Sexually Selective Infanticide (SSI)

    This theory claims that male bears kill cubs so the mother will no longer lactate and therefore be able to go back into estrus (“heat”).   Flaws in this theory include:

    • There is no guarantee the infanticidal male will get to mate with the sow whose cubs he killed.
    • Putting the sow back into estrus does not guarantee that the infanticidal male will be the one mating with her, another more dominant male may end up mating with her.
    • Infanticide occurs outside of mating season.
    • Females sometimes kill the cubs of other sows.
  2. Cubs as a Source of Food

    Bears are cannibalistic.   Even subadult and small adult female bears can fall victim to predatory attacks by larger bears.  A cub may be considered as an easy source of calories for a hungry bear.

  3. Reduced Competition for Scarce Resources

    Eliminating cubs is an efficient way to reduce competition for food resources and mating partners.

Infanticide occurs with bears, bobcats, mountain lions, and other mammals.

Knowing about something is much different than experiencing it up close and personal, 20 feet away!

This article tells my experience photographing a mother bear, referred to by NPS rangers at Katmai NP as “Bear 132“, and her two spring cubs (born earlier in 2018).

Just another beautiful day in July on the Brooks River.  Bear 132 and her cubs in a fairly safe area downstream of the falls, floatplane over Dumpling Mountain.

The event was disturbing.  I will not show many of the photos or video I took of the event.

If you choose to read more below, please realize that I have tried to minimize the graphic photos.

Read More

Bear 132 and her surviving cub 12 days after the attack. 

After experiencing this horrid event up close I have even more respect for bears as a species.  Now, for me, the value of a bear that reaches adulthood is even greater than it was before I saw the attack.  A mother bear invests a lot in raising her young.  Bears have some of the lowest reproduction rates in mammals, so even a few deaths in a population can have a significant impact on the entire species.

However, we as humans can help the bears survive is well worth it!

In every walk with nature one receives far more than he seeks 

— John Muir

26 replies
  1. Linda Haehnle
    Linda Haehnle says:

    Ed,
    Thank you so much for your insight and recall of this tragic event. Nature is not always kind, and does not always make sense, as you have pointed out…….. this had to be a horrific experience to witness. I was emotionally distraught reading so can only imagine how you felt watching the scenario unfold. Having been to Katmai and photographed the beautiful bears and watched the cubs interact with their Moms is a wonderful lesson on the bond and behavior between them. Am so glad the Bear 132 is ok and still has one cub left to raise. I appreciate the list you provided to help the bears – as I too am a bear supporter and feel there is much we can do to help them.

    Reply
    • Ed MacKerrow
      Ed MacKerrow says:

      You are welcome Linda, and thank you for supporting the bears! I am sorry the article is disturbing. I was on the fence about sharing the experience, or not. I chose to write about it since in the long run, I think it helps us all appreciate the bears more.

      Reply
  2. Lin Pope
    Lin Pope says:

    That was so interesting to me and I have enjoyed getting to know the ins and outs of bear behavior, etc. thank you for all you do and passing on valuable information to people who want to learn more about bears. I find their life and habits so interesting and find them fascinating. I witnessed online the event with 132s cub and it was very disturbing to me but know that is a part of nature and comes down to the survival of the fittest. Although a lot of nature can be very sad, I realize it’s all part of nature and how it’s all in the Master Plan of the universe. Thank you for your email!

    Reply
  3. Judy Gusick
    Judy Gusick says:

    Mother nature is a bitch at times…..:( Intellectually “knowing” some of it and actually witnessing these awful events is entirely something else. We have to accept all of it even if we don’t like it. Glad it didn’t turn you off bears as disturbing as the event was.

    Reply
    • Ed MacKerrow
      Ed MacKerrow says:

      So true Judy! I must admit that even now thinking about the event disturbs me. I had seen some very close calls in the past and turned away as they unfolded. In both of those cases the mother was able to defend against the attackers (one time it was a female bear as the attacker). This experience will stay with me forever, and that I appreciate in the long run since it has increased my respect and appreciation of the bears in their natural and undisturbed settings.

      Reply
  4. Karl Chiang
    Karl Chiang says:

    Very disturbing! This happens in humans and is called child abuse etc. Humans like 856 go to jail. Why don’t the rangers put it down since it has a history of such aggressive behavior? Or at least move the boar to a remote area. I am convinced that some animals are more “bad” than others like humans. Doing nothing just compounds the problem!

    Reply
    • Ed MacKerrow
      Ed MacKerrow says:

      It is disturbing Karl. I too have thought about many of the questions you raise. The “answer” it is “just nature” is not really a complete answer. As grizzly bear habitat is being fragmented, climate effects, and other challenges, it is important to realize that since bears have such a low reproductive rate, that even small numbers (percentage) of morbidity in a bear population can have a significant impact in the overall population. They do not reproduce like rabbits or deer.

      The bears that come to Brooks Falls come from far away. They are forced into a social situation, and they are anti-social. Their food drive to travel very far to Brooks Falls is a challenge in relocation, however, it is a potential option. I find it interesting to think through the motivations for infanticidal behaviors, the common “off the cuff” answer you hear/read is “so that males can put the female back in heat to mate with her”, however, after digging deeper in the research this explanation is not so convincing. It could be one of many reasons.

      I do agree with you that in most species, including homo sapiens, that there are antisocial personality disorders. They have studied this in primates, and of course also in human society. Psychopathy (like) and other disorders are feasible in non-human species. Perhaps 856 is one of these cases? The science of what animals think and feel is relatively new, however, I studying some of the research now and feel it is good research and has been overdue for so long.

      Reply
  5. Jess Alford
    Jess Alford says:

    Ed,
    Thanks for the article, quite interesting. I’m a photographer. My career was in advertising photography in Dallas for many years. Now in retirement I live in the Manzanita Mountains in New Mexico. I’m 85 now but I still love to shoot. For the last couple of years I’ve been shooting mostly birds both here at my home and at Bosque del Apache National Wildlife Refuge about an hour or so south of Albuquerque.

    Unfortunately we’ve been having a black bear problem here in the area. Climate change has brought us severe draught and the bears are starving. I been feeding the birds for twenty years but have had to take down my feeders because the bears looking for something to eat crush them and also present a problem for the entire neighborhood looking for anything to eat. I’ve had a mother bear and two cubs in my yard and even on my back porch. Most of us hate to call the Forest Service because that usually ends with the bear or bears getting darted and moved and the bears often come back or run into a bad situation in the new location. We can only hope for the best.

    I’ve wanted to come to Katmai for a long time but have had a little health problem. I feel good now but age is creeping in but who knows, maybe some day.

    I’m working on a website and will let you know when it’s done. Thanks for sharing your bear knowledge.

    Thanks for sharing your bear knowledge,

    Reply
    • Ed MacKerrow
      Ed MacKerrow says:

      Thank you, Jess, for reading the article and for your reply. Climate change is impacting the forests the bears live in, not only here in New Mexico, but many places. In the long run, forest fire scars are good for bears, as they open up dense canopy that is not the best for bears. They are mostly found in meadows, avalanche paths, and fire scars. I hope you do get up to Katmai, Brooks Camp and Lodge is a good way to do it if you are having health issues.

      Reply
  6. Laurie Alsted
    Laurie Alsted says:

    Ugh! Loved your blog writing, Ed, and the raw, up close images you share with the rest of us. I so admire your passion and love for nature in all her creation.

    Witnessing the brutality of nature can be so horrifying. Personally, I look away even while watching nature shows on Nat Geo or The Discovery Channel let alone up close an personal. I can’t handle the brutality of a kill in nature. I know it’s there, but my tender heart has a hard time handling it. For that I’m glad.

    Can’t help but add a note of caution for your own safety, Ed.

    Thank you for all the absolutely stunning images you selflessly share with the rest of us. You are a treasure!

    Reply
    • Ed MacKerrow
      Ed MacKerrow says:

      You are welcome Linda, you are correct, I knew that someday I would probably witness this. It is part of nature, and luckily most of nature is beautiful and enjoyable. Things like this I put in the category of educational, witnessing this has made me think more about things.

      Reply
  7. Stacey Schmeidel
    Stacey Schmeidel says:

    Ed —

    Thank you so much for this excellent post — a careful, thoughtful and insightful look at the complicated events of that evening.

    Thanks for all you do to help share the stories of the bears.

    Reply
  8. Robin Easton
    Robin Easton says:

    Hi Ed, I read your account with immense interest, what a brave, honest and incredible article and experience to witness. I REALLY enjoyed it. Since I’ve lived a lot of my life in wild, remote areas I found none of this unusual or offensive. I read your story with great fascination and a curious mind, pondering the possible motivations for this behavior in bears and other species. The possible “whys” of it all intrigue me.

    When I lived in the jungles of Australia (years ago when it was completely untouched and very wild) I saw so many astounding wildlife encounters. In my book I think I use the phrase “Things Eating Things”. When I first “went wild”, I was horrified by predators eating their prey, and even cannibalistic tendencies, but with time, observation and educating myself I grew to better understand and, as you said, develop immense respect for the survival skills of other species. When I really understood what it took for many species to survive I grew to revere them. I learned to NOT intervene. I began to see more and more Nature’s purpose and realized I was but an infant in my understand of such events. I felt hugely humbled by these creatures’ ability to not only survive but often thrive in a world ready to eat them, or simply just kill them.

    This “awakening-into-respect” was especially potent when it was applied to highly poisonous or dangerous-to-humans species. (Which there are many of in Australia. I grew up in Maine.) Just as you mention in your article, I too shifted from fear to awareness. In fear we can tend to “react” more irrationally and are often not calm and clear thinking, we are not “choosing” our response. Wild Beings being SO highly intuitive and sensing of the world around them can easily pick up on fear. They can in some (or most) cases smell it.

    And you are right. Yes, Nature is sublime and beautiful to the point of exquisiteness. It is healing, soothing, and for one like me, it is my very Life. BUT….Nature also is VERY real, unabashed, brutal, whether that is a class 5 cyclone or a raging forest fire (which I’ve been through) or a saltwater crocodile that has developed a taste for human flesh or it simply mistakes a crouched human for its natural food of feral pig or wallaby), or a nest of inch long ants that can jump 3 feet into the air and bites from 30 of them can kill you). Yes, Nature is ALL of it. I think that is what I find so endlessly compelling. Thank you for taking the time to share this incredible story.I found your Facebook page and will check out your website.

    Reply
    • Ed MacKerrow
      Ed MacKerrow says:

      Hi Robin,

      Thank you for your insights and comments! Very interesting. I will check out your book, it sounds right up my alley.

      Fear can really mess with humans minds, and fear is now used to help sell things (guns, knives, etc.), and in the log run fear is probably the most dangerous thing. Respect for apex predators and their home is the key (I am sure you know this based on your experience).

      Thanks again Robin!

      Ed

      Reply
  9. Amanda
    Amanda says:

    Hi Ed I read most of your article when Melissa first posted the link in the Brooks Falls group. I finally got the guts to read it entirely tonight. Thank you for your account and the way you presented it. We were at Brooks falls from July 1st to 4th and I was on the Brooks Falls platform when the two board took off. My partner had returned to the camp earlier so I decided to walk back when a large group headed back. I arrived at the Riffles confused by the sounds from in the tree and the volunteers had already closed the platform. You must have already headed to get Mike and Andrew. The aftermath of the scene was awful enough to view and I am sorry you witnessed the event in so much detail and I can understand to a much deeper level the look of horror on the faces of the couple who had seen it and were still in the treehouse area. I realise the memories you have are much sharper and deeper and more desperate than the small amount I saw but I have tried to console myself -especially that first night by realising the awe of nature – even when it is ugly. Very ugly. The new parts to the story I learnt from your article make the scene even tougher than what I had imagined. But it also makes me amazed at the strength and dedication from 132. I am glad to have read this (and very quickly) looked at the pictures. I remember that next morning the sombre feeling in the dining hall at breakfast and someone saying that they didn’t much feel like taking photos of bears for awhile. Thanks again.

    Reply
    • Ed MacKerrow
      Ed MacKerrow says:

      Hi Amanda,

      Thanks for reading the article and sharing your experience. We must have just missed each other, after I told Mike and Andrew I headed back with two friends, one of which was right next to me during the horror, the other, my friends mother, we yelled at to stay back and not witness the killing. We were in tears on the way back down the falls trails.

      It was sobering to experience and still to this day there are many photos and video that I took during the killing that I do not look at. I did give all my photos and video to NPS for the sake of documentation.

      You are on correct about the strength and dedication of Bear 132. As I watched her approach Bear 856 with her cub underneath him I could really sense her desire to do “something”. She tried hard to do so, however with his size he overpowered her. I was convinced she had suffered a fatal attack. Luckily, I was wrong, and strangely it was hard to see any external damage on her, although I am betting she had internal injuries and her underside, which is hard for us to see most times, she might have scars we cannot see. I bet she has emotional scars.

      It may have been me that next morning saying they were not interested in taking any more bear photos. It did affect me, and still does.

      The event upset many people. In the long run that does carry some positive learning, at least I know it does for me. What can we as humans do, if anything? Surely, infanticide does happen way out in the wilderness, far from human impact and influence. My view is that just being at Brooks Camp does impact the bears some. They adjust their behavior due to the presence of humans. Now I realize, more so than before, that when I see a mother with cubs, I need to really think how can I minimize her stress, danger, and energy expenditure? Are my behaviors, or location, going to influence her to move into an area that is less safe?

      As you probably remember, Amanda, there were a lot of bears at the falls, and downstream of the falls, that night. Whenever I see a mother bring cubs, especially spring cubs, towards the falls or riffles, I start to worry. I was suprised to see her, from my position on the Falls Platform, show up with the cubs at the Riffles Platform. Why did she feel the need to bring the family there? We will never know for sure. However, some possible factors to consider include, she was not catching any fish downstream, she was pushed there by other bears, or did not feel comfortable with people downstream in the river; and chose to go to the riffles with her cubs instead. Probably all of the above were influence factors.

      In September I will be back to Brooks Camp, and some more remote parts of the park. I am looking forward to seeing a healthy Bear 132 and her fat spring cub. I hope that happens 🙂

      Reply
  10. Karl Chiang
    Karl Chiang says:

    Ed thanks for your reply. If 856 had attacked a human, even if it was a human who got too close, the Rangers would have killed it because it a Dangerous animal and tasted human blood! Yet it is “ok” to kill one of its own kind ! Reminds me of the Police in Chicago watching the gang killings. As long as it doesn’t spill over in white suburbia. I am a cynic. Double standards in life!

    Reply
    • Ed MacKerrow
      Ed MacKerrow says:

      Thanks Karl. Most of the time I do not support killing a bear that attacks a person, especially when it was the person’s fault due to intentional bad behavior on the human’s part. It is complicated for sure and there are no easy answers.

      Reply
  11. Julie Jenkins
    Julie Jenkins says:

    Ed,
    So sorry you had to witness that horrific act of mother nature but I am grateful that you shared the reality of your experience with us, and am particularly grateful for your mercy in not exposing us to the visuals that I imagine scar you to this day. Just your words reduced me to tears. Life can be cruel and unfair ~ whether you are a human or an animal. I so love all your photography, you really allow us to share to beauty, majesty and raw power of the bears and I always enjoy it. Can’t say I really enjoyed this post (except for the post attack Mother and cub photo – yay for the under dog) but you keep it real and I so appreciate that. I hope it time this incident dims in its horror and you are left with overwhelming images of all the amazing, beautiful encounters you’ve had. I would be remiss if I didn’t mention how much I love all your landscape photos as well. I continue to hope you’re working on a coffee table book!!! Take care.

    Reply
    • Ed MacKerrow
      Ed MacKerrow says:

      Julie,
      Thank you for reading the article and for your kind compliments. Writing this article was hard, bringing back memories of some bad stuff, however, I felt the need to share the experience, perhaps so we can all appreciate how valuable wildlife is to the world.

      Reply
  12. Karen Potter
    Karen Potter says:

    Great blog, you have a keen eye as well, thank you ED,
    Mother Nature rules in AK, as it should be.
    Yea well Karl Chiang, I would like to invite you to study the subject a little more before making such outlandish, and frankly false claims. Misleading others with false information is unacceptable in my world. If you in fact do take the time to study the subject, you will then learn the truth. I hope you will one day, learn the truth.

    Reply
  13. Luke
    Luke says:

    Very informative, riveting, insightful account of this incident – as it was thankfully not on the Bearcam it is good to have a first hand account of what happened without sensationalizing or minimizing the events – 856 killing the cub was horrible but I in know way think he is a psychopath or needs to be ‘put down’ as one of the comments said – as far as we know he has never so much as breathed hard on a human, if he had he would of been ‘relocated’ or worse a long time ago – I think he is just a hyper dominant bear who’s life is centered on staying at the top of the hierarchy, while most of the other bears top priority is eating – but he mostly goes after the other boars and generally leaves the subs alone, it’s the new born COYs that send 856 over the edge from time to time for some reason, and nobody can say for certain what that reason is.

    Reply

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