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What’s This? No. 18 should be self-evident. The winner of this challenge, however, will name the species that left its mark on this rock (which I suspect is Shinumo quartzite). I photographed this on Phantom Creek in Grand Canyon National Park on March 4, 2014. For extra credit name the other “dropping” in this image.

Added March 17: We have a winner! 


Well, we have many winners. But Mark Council was first to identify this as the footprints and droppings of American Dipper. Mark’s answer came in to the blog a mere three minutes before our second-place winner, Sue Cloutier, who is the Ken Jennings of What’s This? Also check out some of the more creative answers in the comments below.

American Dipper is our only aquatic songbird; those footprints do indeed suggest the feet of a “perching bird” (in the order Passeriformes) rather than webbed feet. Dippers nest along streams across the western US and Canada. Water does truly roll off this bird’s back; it swims and walks underwater on stream beds, where it feeds on aquatic insects. Meanwhile, the eco-astute Audrey Clark noted the Fremont cottonwood (Populus fremontii) leaf on the boulder, which also helps with scale in this image, and the yellowish duckweed gathered in the eddy.

Find the entire suite of What’s This? challenges here.

  1. Ray Barnes says:

    water ouzel ? The poplar leaf imprint is a clue as to scale

  2. Mark Council says:

    That would be American Dipper. The Polish Dipper’s super duper rare here…

  3. Philo says:

    This won’t help but the question brought it to mind:

  4. Sara Backer says:

    These are sacred pictographs of the Havasupai tribe commemorating a finger shadow play about the battle between Rabbit and Rooster. Whatever species pooped on it should be ashamed of itself. . .and afraid. Very afraid.

  5. Larry says:

    Melted cookies-and-cream ice cream

  6. Julie says:

    How about American Dipper droppings (and a birch leaf?)

  7. Willem Leenstra says:

    Isn’t it rock snot (aquatic alga Didymosphenia geminata)? My second guess is Mileyl Cyrus’s tongue.

  8. Leda Beth Gray says:

    American dipper

  9. It is the rarely seen face of shinimo

  10. Kristen says:


  11. PMP says:

    Dipper poo

  12. Marialisa says:

    Shinumo quartzite? Looks like a sweet potato. A sweet potato with bird poop on it.

  13. Susan Sawyer says:

    Dipper? Wet footprints?

  14. Sue Cloutier says:


  15. Mark Council says:

    Since there’s nothing as a scale reference, I have to guess as Dipper guano. Tell me I’m right…

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