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Forest Floor Mystery: Pellets? Old Scat? Cache?

6-15-16   bones 378

Lying at the base of a large Eastern Hemlock I recently found two piles of bleached bones.  One pile consisted of mostly vertebrae; the other pile had numerous tibias, humeri and ribs.  All were the appropriate size and shape to have come from several Eastern Chipmunk skeletons – at least four or five.   How did they end up in two distinct piles?

The lack of any fur indicated that regardless of how these bones came to be here, they were deposited quite a while ago.  The lack of any partial skulls or jaw bones and the large number of bones in each pile led me to believe that these were not the remains of two pellets that had been regurgitated by resident Barred Owls. No wild owl pellet I’ve ever dissected, including the large pellets cast by Snowy and Great Gray Owls, has contained even half this many bones, and most contained at least part of a jaw bone.

If not pellets, then scat?  How likely is it that a predator could catch and consume multiple chipmunks rapidly enough so that they would end up in the same pile of scat?  One feasible explanation could be that a fox, coyote or fisher preyed on young, inexperienced chipmunks, but the bones were adult-size bones.

Perhaps these two piles are the remains of a predator’s cache – perhaps a bobcat?

The possibilities are endless as to how this chipmunk graveyard came to be.  However, none of the theories proposed here can explain the dissimilarity between the types of bones in each pile.  If any naturally curious readers have insight into this phenomenon, your thoughts are welcome!

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35 responses

  1. Cheron barton

    Here a challenge!!😱

    Sent from my iPhone

    >

    June 14, 2016 at 8:06 am

  2. Jean Dedam

    could a parent have fed a young one at that site retaining part of each chipmunk for itself and giving pieces to the young from the same part of the animal each time.

    June 14, 2016 at 8:15 am

  3. janetpesaturo

    Homo sapiens dissecting pellets and sorting bones. Perhaps they carried the skulls away with them.

    June 14, 2016 at 8:28 am

  4. Could the area have been flooded with rain and the smaller lighter bones floated and settled to a slightly lower area next to the original location?

    June 14, 2016 at 8:30 am

  5. LindaCS

    Evidence of Chipmunk Anatomy 101 at Gnome and Woodland Fairy University. Skulls are on display inside a nearby hollow stump.

    June 14, 2016 at 8:34 am

  6. mariagianferrari

    A bone-collecting bobcat with OCD? How far in the woods is this? Could a kid have sorted and arranged them?

    June 14, 2016 at 9:20 am

    • 🙂 No way a child could have been in this location, I’m afraid. Much more likely an OCD bobcat!

      June 14, 2016 at 9:41 am

  7. Gail

    I have to agree with Janet. After seeing many groups of school kids dissect pellets, they naturally sort bones by size. If you are lucky enough to find a skull, that’s your easiest way to ID the remains. I think you found a pellet site after another human had dissected them. Great mystery! Thanks.

    June 14, 2016 at 9:28 am

  8. Sydney

    A dumped stew pot or anatomist’s brew? Most of the bones from a dumped pot or bowl would come out in the first dumping, with a second effort to get the small bones that might remain in the curve . While the bones look bleached and aged, they seem to have almost no debris on them, implying the piles are more recent then not.

    June 14, 2016 at 9:42 am

  9. david putnam

    Perhaps two animals shared the chipmunks over time; one preferred white meat, the other legs and thighs.

    June 14, 2016 at 9:51 am

  10. Karen Fuchs

    Could it have been done by humans?
    Where was this found?
    Love your posts and knowledge.
    Constantly curious,
    Karen

    Sent from my iPhone

    >

    June 14, 2016 at 10:33 am

    • I should have mentioned that the bones were in a location highly unlikely to have had anyone, especially a child, visit.

      June 14, 2016 at 1:55 pm

  11. Jim Lafley

    Although I really like the University idea, I would think Janet’s comment of a person sorting the bones and carrying some away makes the most sense.

    June 14, 2016 at 10:35 am

  12. Rachael Tolman

    It looks like something a bower bird would do. Who else makes a mating display that’s local?

    June 14, 2016 at 12:53 pm

  13. Elizabeth

    My guess is an older animal fed the easier-to-eat legs to young and ate the bodies itself.

    June 14, 2016 at 2:15 pm

  14. Could it perhaps be a weasel? They keep heads as trophies (weird, I know) lining them up in their burrow, which might explain why you found no skulls. And they just might be into dissecting the parts, too? A great mystery!

    June 14, 2016 at 8:46 pm

  15. Rodents chew on bones and antlers, is it possible a rodent was making a separate cache of the best/biggest bones?

    June 14, 2016 at 8:49 pm

  16. Hillary Filios

    My guess is that it is a cache, probably of a rodent collecting calcium sources. I don’t think it is scat or pellets, not the evidence of that. I will look forward to see what others think.

    June 14, 2016 at 9:32 pm

  17. We had a cat that only ate the heads of mice, could one animal have eaten the heads and a second eat the rest of the body and somewhere else there is a pile of skull fragments?

    June 15, 2016 at 7:32 am

  18. Peter Kallin

    Mary-

    Not sure but your picture bears a remarkable similarity to one I took in April when there was still a fair amount of snow on the ground in places. Mine had some fur and jawbones and is actually entirely on a red oak leaf that I was holding in my hand when I took the picture. It was also at the base of an Eastern Hemlock. I assumed it was a barred owl pellet that had degraded a bit. You can estimate the scale by some of the hemlock needles in the picture. I think the bones in my picture were probably mice rather than chippies.

    I think the relatively undamaged bones in your picture makes it more likely to be something regurgitated rather than excreted. Do you have great horned owls in your area? Maybe a bobcat or coyote that ate a bunch of chippies and then threw up? My dogs and cats do that periodically.

    Peter

    June 15, 2016 at 8:38 am

    • Hi Peter, THanks so much for your input. I tend to think you are right about the pristine condition of the bones – the separation of the types is puzzling, as is the number of bones, for a pellet, but both of your theories seem the most plausible to me. WordPress does not allow for photos to come through. Could you possibly send yours to me at mholland@vermontel.net ? Thanks so much!

      June 15, 2016 at 9:56 am

  19. Neill Bovaird

    I think at least some of this is frog.

    June 15, 2016 at 11:14 am

  20. Neill Bovaird

    Frog skeletons!!

    June 15, 2016 at 11:16 am

    • I have a frog skeleton sitting right in front of me, and I’m afraid I don’t concur…neither bones nor vertebrae are right. They are identical in size and shape to an eastern chipmunk’s, but that would have been a great explanation!

      June 15, 2016 at 3:20 pm

  21. dawn

    Discussion with Neill Bovaird points to the possibility of there being a large amount of frog skeleton there, which could account for lack of hair.

    June 15, 2016 at 11:24 am

  22. I am inclined to think a bobcat or perhaps a fisher cat found a favorite spot to dine and regurgitated the bones, but unsure of what became of the skulls…
    BF…

    June 15, 2016 at 11:29 am

  23. Hmmm…I know you’ve said it’s a place unlikely to have human visitors, but assuming you are human & did not take the photo using a telescope, it must be possible for a human to access it, unless perhaps it is gated, fenced, locked & topped with barb wire (e.g., on prison property) or constantly guarded by fierce watchdogs, or maybe immediately in your back yard or a friend’s who is normally at home & has intruder alarms, or was surrounded by sheer cliffs, it’s hard for me to imagine a place that would have trees & wild creatures but could not be reached by a budding naturalist.

    One of my sons was tall, skinny, hiked up mountains, scrabbling up rock surfaces, bushwhacking, etc., by the time he was 12. I can imagine someone like that, perhaps some day to become a naturalist, or an orthopedic surgeon, or nature photographer, or writer, roaming in a difficult area, scouring for owl pellets, dried up dung, bones left behind by scavengers, etc. Perhaps making a number of finds with chipmunk bones & wanting to examine them, following a tendency to sort, at least roughly or for a while. Maybe even taking time to sketch or photograph some of them. Or visiting more than once. Maybe under the leaves a few yards away were some piles of bones from birds. Perhaps it was long enough ago that the bones have bleached & been cleaned since, & slid around a bit. Or were already clean, thanks to predators.

    (I admit, I am thinking not only of my sons, but of myself, around 7 years old, finding a dead bird & using some sticks to dissect it. And my niece, in a heron rookery, closely examining — with her eyes only! — a dead chick that had fallen/been shoved from its nest, & caught on a low branch. She was in med school then.)

    And the skull & jaw bones? Into her/his pockets for further examination at home. (After all, some folks are just… !!)

    June 15, 2016 at 11:04 pm

    • Ooops…. just naturally curious!!

      June 15, 2016 at 11:05 pm

    • I suppose anything is possible!

      June 16, 2016 at 7:00 am

  24. Peter Kallin

    One more theory: Couple of turkey vultures scavenged a bunch of dead chippies killed by fishers or other weasels who stole the skulls. They then flew to your hemlock tree to roost and barfed up the bones in the middle of the night.

    June 16, 2016 at 9:17 am

  25. I agree with the humans theory.

    June 17, 2016 at 2:24 pm

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