Monday, October 06, 2008

Track of the Week 3

The Mystery:

This picture was taken on the same early March trip to central Washington as last week's mystery.

The Questions:
For all of these questions, you may want to click to enlarge the picture to get a good enough view.

1. What is the predominantly used gait?

2. What species? (or as close as you can get)

3. Why are there sections in the middle of the heavily used paths that only have a couple sets of tracks in them?

The last question is one I may have still been puzzling over if I hadn't been working on it with other people. I'll be interested to see what ideas you all come up with.

I'm adding the picture below in the hopes that it will be helpful. I'm not sure that it will be any more helpful than the picture above, but at least you will be able to see a closer view of the individual tracks.

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DeAnna said...

That's funny, I just took about a million pictures of these same tracks in the Oregon Dunes a couple weeks ago. And I'm a little embarrased to admit that I don't know what they are. A small rodent, for sure, but I don't know what sort of little mouse/rat/vole lives in that sort of habitat, although apparently whatever they are, there are approximately 4.7 shittons of them in the Oregon Dunes.

I was surprised to find neither fox nor coyote tracks where I was in the dunes, since I'd think this was a canine smorgasbord. Probably they were there and I just didn't find them.

There were the same gaps in trails where I was too. I hadn't actually pondered it, but now I'm guessing that those gaps happen on inclines where the little guys jump up and down each time.

I always forget the words for the various gaits, but I think the ones that I saw were mostly in the same gait as a rabbit, where the two front feet come down first, often slightly off from parallel, and then the back feet register right next to each other just ahead of the front feet.

Jonathan said...

Yeah, I think this species is the same as (or closely related to) a species as the dunes.

One of the most useful tools I've found for identifying tracks I'm unfamiliar with is to create a master list of possibilities. Of course one of the most effective ways of doing this is looking in a field guide or at online resources where you can figure out exactly (more or less) who lives there. You can do it more informally as well, such as Deanna's "mouse/rat/vole". One potential problem with that route is you can miss species you weren't aware of. Since I began tracking more seriously, I've learned of several species I'd never heard of. That said, I think that this species is one of the more common ones. But central Washington does have a lot of cool little rodents that it would be worth exploring if you have any interest in the area.

I'm also surprised you didn't find fox or coyote tracks. Seems like they have been among the most common tracks I've seen when I've been down there. I wonder where they went? Was there any unusual weather (or unusual anything else) going on while (or shortly before) you were down there?

I used to have difficulty remembering gait names too. Great that you know the body mechanics though! Just the other day I decided to look at some animal videos on youtube and I found some cool examples of animals doing a 2x2 walk which was the first time I really understood how the body was moving differently than in a diagonal walk.

M Goff said...

Originally I was thinking the gaps were due to slope hopping as well. I was going to say something about how difficult it was to determine the topography from the photo. However, I realized that even if the widely spaced tracks are due to a slope, it seems pretty clear that there are not enough tracks there to account for all the tracks in the higher density areas. In other words, the gaps had far fewer animal crossings than the dense part of the trails, though it's not clear to me why.

Another idea I had is that something came along and erased tracks. It does appear that the dense tracks tend to be older and/or made in dry sand while the tracks in the gaps look like they were fresher and/or made in damp sand. Perhaps a depression was filled with water when the bulk of the tracks were made? Again, the difficulty of evaluating the micro-topography makes it hard to figure out if that's reasonable.

Jonathan said...

It seems like this one may be more difficult than I had thought. I would like to challenge people to come up with 5 species they think the tracks could have been made by.

I would also like to hint at the last question: Considering the relative ages of the tracks is probably a good idea.

Quigley said...

They look like woodrat tracks to me. I would guess bushy tailed? The gap in the trails is strange because the camera kind of warps the edges of the picture, so I can't grab any sense of perspective, but it looks like the gaps are part of a snaking trail. I don't see any signs of drag, and the plant stalks are not bent or broken, so I would have to rule out any animal or any object lying across the tracks. It looks like an area of water flow. The crack seems to back that up, too.
At first, I didn't see the sneaker tracks in the upper left corner, so the perspective looked like an aearial view of deer beds and snowshoe hare trails. Then I realized that the "deer" or "moose beds" were actually another footprint and what appear to be elbow or knee prints with extra weight being on the right (uppermost) knee/elbow as if someone was getting a better angle on the tracks or for a photo. From the footprint, the next track should be in the plants, and I think I see it, but I'm not sure. I'd like to know what the blue object is on the left side of the photo, too.

Jonathan said...

It does look like there is a (human) foot print in the vegetation near the bottom, though the plants don't look particularly damaged. I'm not sure if that is the next track, and if not where it might be.

I'm also not sure what the object is in the upper left corner (I am assuming that is the same one you are referring to Quigley), though it looks like a bit of trash to me.