Changing Planet

The Passing of a Titan

An intimate portrait of F109, an adult female mountain lion tracked by Panthera’s Teton Cougar Project in northwest Wyoming.

Contrary to popular belief, mountain lions are not all the same. They are as distinctive in personality as we are. Some are bold, others stick to the shadows. Some are social, others avoid interactions. Some hunt elk, some prefer smaller fare. Some are productive, successful mothers that rear numerous kittens to young adults, and others never raise a single kitten to independence. It’s productive females like F109 that are so important to the future of mountain lion populations.

F109, an adult female mountain lion followed by Panthera’s Teton Cougar Project, was exceptional by every standard. She was near impossible to catch with hounds. She was a master of interwoven fallen trees and would leap to mount them, weaving loops across trunks without ever touching the ground. She would climb trees when dogs were close, and leap from one canopy to another, only to descend some distance away. We reveled in the fact that she was safe from hunters; her intelligent evasive strategies left their hounds (and ours!) in drooling befuddlement. F109 was the cat we’d tell stories about around the fire; we revered her tenacity and her indomitable spirit. Whenever a hike was long and hard, we’d say to ourselves, “at least we’re not on a 109 capture!”

F109 raised several litters of bouncing kittens to independence, all the while traversing the highest, most rugged terrain our study area in northwest Wyoming had to offer. She survived encounters with bears and wolves, as well as encounters with humans and bull elk. She endured bitter cold and landslides. She showed us exactly what a fortified den looks like (See A Fortress for Kittens). In 2013, she was the first and only mountain lion among those we’ve followed to successfully kill and consume a wolf (See Hunters or Hunted? Wolves Vs. Mountain Lions). Each winter, she also killed several bull elk, which can weigh greater than 700 lbs— more than 8 times her size. She was the first mountain lion we caught on video interacting socially with another mountain lion (See Solitary is not Asocial: Social Interactions Among Mountain Lions), and in recent years she interacted with other mountain lions some 28 times. Over the 6 years we studied her, we gathered data on 195 prey she killed and consumed. Twenty of those kills provided us the opportunity to film and study vertebrate scavengers and document more mountain lion social interactions. F109 taught us what it means to be a successful mountain lion, and as we continue to analyze data and reflect upon our time in northwest Wyoming, she will continue to teach us more.

F109 died this month of natural causes, old age and disease, at an incredible 12 years of age. In a hunted population such as this one, her long life is worthy of recognition. Her collar betrayed her final resting place, and we ascended 2,500 feet to find her high on Sheep Mountain, in the center of her territory. On high, we crossed a final snow-covered meadow to enter the copse of trees she’d chosen.

The mountain was quiet when we arrived, the air crisp and cool. There were nearby signs of a red squirrel, but it did not chatter at our approach or as we lingered over F109’s frozen body. F109’s death will go unnoticed by most, but her absence leaves a hole in the Jackson ecosystem. The local mountain lion community is more diminished for her passing. Our lives, I’m convinced, are more impoverished as well. Thank you, F109.

Look for updates on mountain lions we follow on Facebook. Thanks for reading.

Mark Elbroch has contributed to puma research in Idaho, Colorado, California, Wyoming, and Chile, and lots of other carnivores along the way. He earned his PhD at the University of California, Davis, where his dissertation research focused on puma ecology in Patagonia in the presence of endangered humeul deer. He has authored/coauthored 10 books on natural history ( and numerous scientific articles published in peer-review journals. Mark is currently a Project Leader for Panthera, a US-based non-profit that conducts science to promote wild cat conservation worldwide.
  • Helen McGinnis

    Very sad, but she did live a long time for a wild puma, and thankfully, she wasn’t “harvested.” Thanks to modern technology, we can follow the lives of “celebrities” such as P22, Limpy the Lion, and others.

  • Jeannie Wiggins

    What a life! I’m glad she passed in her own environment, under the beautiful skies of Wyoming. Rest in peace, dear lion.

  • Gigi Leek

    Go rest high on that mountain . Your work is done

  • Gigi Leek

    Go rest high on that mountain

  • Brandy Powers

    Thank you Mark for such a beautiful tribute. I have followed her for a long time and am very sad to hear of her passing. A prayer for her and for the space she leaves in our hearts tonight…
    Be at peace F109.. be at peace….

  • Pat Nelson

    Thanks for this lovely tribute that honors her value. I’m glad she passed in her own time and a place of her choosing.

  • Pat Nelson

    Thanks for this lovely tribute that honors her value. I’m glad she passed in her own timing and in a place of her choosing.

  • Mauro Lucherini

    So happy that she died of natural causes. She deserved it! I wish the pumas we work with here had the same opportunity…

  • Tammy kilgore

    I’m glad she found her own resting spot. Not one from a human . rip f109

  • Robert Bennett

    Thank you for sharing this, and thank god she died of old age and not by a hunter.

  • Kathleen Cencula Comer

    Thank you for a very Beautiful tribute to a shining example of being a mountain lion at it’s Best. A legend. Sad to see her pass, but so glad it was of natural causes and not a hunter or a lost fight with another animal. Enjoy Peace 109

  • John Shoe

    Farewell, F109 ❤❤❤❤
    May your legacy live on forever , precious heart !

  • Bruce S. Thompson

    Posts such as these help bring out the best of us from our too-infrequent expressions honoring the best of the vastness and them…

    “We need another and a wiser and perhaps a more mystical concept of animals. Remote from universal nature, and living from complicated artifice, man in civilization surveys the creature through the glass of his knowledge and sees thereby a feather magnified and the whole image in distortion. We patronize them for their incompleteness, for their tragic fate of having taken form so far below ourselves. And therein we err, and greatly err. For the animal shall not be measured by man. In a world older and more complete than ours they move finished and complete, gifted with extensions of the senses we have lost or never attained, living by voices we shall never hear. They are not brethren, they are not underlings; they are other nations, caught with ourselves in the net of life and time, fellow prisoners of the splendor and travail of the earth.
    —Henry Beston, The Outermost House

  • Nadine B

    We have a panther colony here in south Florida which is hopefully preserving the species and is monitored by the State Wildlife Commission. They do a GREAT job; but it is an ongoing effort for them as the kills from autos, other means, etc… are difficult….
    I give you accolades for your work in this area…In truth this is our true heritage for our children & beyond…. THANK YOU !!!

  • Juergen Rogner

    Why on earth are these amazing animals being hunted!

  • Laura

    We need more wildlife education about mountain lions and other wildlife so people appreciate and protect them

  • Gill Blower

    Thank you so much for sharing this tribute to F109. She was an amazing animal and with a truly amazing character and the fact that she had a natural death and chose her own last resting place is fitting. May she be at peace and may her offspring continue her legacy.

  • LC Stalling

    Thank you for this tribute, a joy to read and so happy she was seen and appreciated.
    I would love to know if you intend to follow up on her grown offspring, to see if they continue her legacy by choosing good dens, hunting big game, and evading through the trees. I liked reading about her here and in the links you posted, and would love to think she passed on some of her habits.
    I’m so happy groups like yours study and educate about these beautiful and amazing cats.

  • Kim Cabrera

    RIP F109

  • Sheryl

    F-109 was truly a magnificent lion. Our native wildlife is so feared and misunderstood. It’s high time we start teaching people to coexist, love and respect these great animals before it’s too late. Trophy hunting, that barbaric ugly cruel pastime, needs to be banned. NO MORE HUNTING, especially our native predators like mountain lions, wolves, coyotes and bobcats. Time to respect and protect. R.I.P. 109. I’m so glad she had a long life and died of natural causes, as it should be.

  • Mike Smith

    Thank you for a moving tribute to a wonderful animal.

  • Eve Thomason

    Thank you, Mark, for the beautiful tribute. I am grateful for F109’s contribution to our understanding of pumas.

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