Monday, February 15, 2010

Fotter Tracks

Janet writes: Would anyone care to hazard a guess as to which are
otter and which are fisher tracks? I know what they are based only on
the behavior of the animals I was tracking. Is it really possible to
determine which it is based only on track appearance?

The tracks in the photo without a ruler measured about 2.5 inches in width.


  1. Not all of those are correct. But since the goal is for all of us to learn what are, and are not, distinguishing characteristics, you get extra credit if you explain why you think whatever you think. Even if you're incorrect.

  2. With otter I look for larger toe pads, webbing of course.

    For fisher smaller toe pads w/ pronounced claws & more defined chevron inter-digital pad.

    Both prints can look alike in deeper substrate, so I was certain I'd miss a few!

  3. Okay, it doesn't look like anyone else is going to take a stab at it, so...

    #1, 2, and 5 are fisher
    #3 and 4 are otter

    I was impressed with #5 in particular, as the toes seem too prominent for fisher, and I would have guessed otter, as you did, Tom. BUT, we know for sure that was a fisher, because Bob Z. actually saw the animal (he even got video of it), and photographed the tracks just moments after the fisher disappeared.

    Maybe the otter's webbing and larger toe pads are more noticeable in shallower substrate, but certainly in a few inches of snow, I am not able to see this reliably.

    I had been assuming that the fisher would have a less defined chevron, since the foot is hairier....but I am not sure...In either case, I am not finding the chevron to differ reliably in the two species.

    I have read that toe #1 is reduced in the fisher, while in otter toe #1 is as prominent as the other toes, and often sticks out to the side. I am not finding that to be reliable, either, (at least in a few inches of snow)

    Maybe if we could see fisher and otter tracks in the same substrate and of the same age, we could use those characteristics to distinguish between the two, but I am not finding them to be helpful in general.

  4. Wow-- I was waay off lol.

    Check out the great pad definition on these fisher prints

  5. Nice photo. And in that one, toe #1 really does seem reduced.