The response to
last week's track of the week was better than I expected. It was great getting so much advanced participation in the comments. My initial plan for this was to aim it at a more beginner to intermediate level though and I'm not really prepared (or knowledgeable enough) to target it at folks interested in studying pressure releases. I hope that such people stick around though and are able to stretch themselves with the pictures I am able to offer anyway (and perhaps as time goes on I will begin to gather more pictures that will be increasingly useful for such study).
That said, I would like to request that if you are a more experienced tracker you leave the answering of the official questions to the newer trackers, at least for the first couple of days after I post them. The way I envision things, perhaps you could discuss the more advanced topics without mentioning the answers to the more basic questions. After a couple of days go by though, please feel free to answer those questions as well.
People who are newer to tracking, please feel free to post comments even if some of the other comments are over your head (some of them have been over my head too!) I hope that people at all levels of tracking skill feel welcome to post their analysis and feel free to ask questions too!
This week's mystery:This picture was taken in central Washington.
Questions:1. What is the species at the top?
The top species is a porcupine. As some of the comments mentioned, the overall shape and pebbly texture in the tracks are characteristic of this species as are the quill drag (though I've seen trails where it is much more noticeable) and the long claws. The claws here don't show up very distinctly, but at the front of each of the tracks they make a disturbance a bit to the inside that is more or less perpendicular to the direction of travel.
Porcupines are pretty interesting in that they have long claws on their front and hind feet. I can't think of any other animals quite like that, and all other animals with particularly long claws that come to mind are diggers and as far as I know the North American porcupine doesn't do much digging. I read that African porcupines will dig for roots though. I've seen a number of websites that claim that the long claws are useful for climbing trees which porcupines do a lot of, but that doesn't seem to line up too much with the fact that of the animals that I can think of that have particularly long claws and the animals that climb trees a lot the intersection is only the porcupine. I've read that their textured feet are also useful for gripping trees (makes me think of those rubber grippy pads for opening jars).
These tracks are near the top of the size range that Elbroch gives in Mammal Tracks & Sign for porcupine. Apparently porcupine are sexually dimorphic with males being larger, but I was unable to find anything saying how much larger they tend to be. But given the size I wouldn't be surprised if it was a male.
2. What is the species at the bottom?
I believe this is a coyote trail. The size range on the individual tracks could work for a red fox or a coyote, but I think fits the coyote better. I believe it is in an overstep walking gait (I will discuss why below) in which case the stride fits much better with a coyote. I've also seen tons of coyote in this area and while I wouldn't rule out the possibility of foxes being around, they don't seem to be nearly as common there.
Based on the size of the tracks, from left to right we have left hind, right front, right hind. In canines the front foot shows up bigger then the hind. The right hind is a little tricky because it appears bigger than the left hind, but compared with the middle track (the right front) the heel pad seems smaller and the overall track seems a bit narrower. With that placement of feet the gait could be an overstep walk, overstep trot or a lope. I think the disturbance in the tracks is pretty low for it to be a lope or a trot, so I think a walk makes more sense there. Additionally an overstep trot like that is pretty rare, where as overstep walks are common.
3. Who came through first?
As was mentioned in the comments, in the left edge of the picture the coyote and porcupine tracks are quite close. It is hard to tell for sure if the coyote track is disturbing any of the porcupine tracks, but it would be hard to believe that the coyote track would remain so undisturbed if the porcupine had walked over it that closely. I would feel somewhat hesitant to say for certain based on that, but I have a picture from later on in the trails that confirms that the coyote came later.
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10 comments:
Besides the overall shape, the pebbly texture still visible in the pads of the upper tracks are a dead give-away :)
The lower tracks are definitely canine, and I'm guessing that they are smaller than the tracks appear at first glance since they seem fairly eroded. I'm not good with my canine measurements, but based on size and habitat, I'm guessing fox.
There's probably some brilliant clue that I'm missing about the timing of the tracks, but based on the clear definition in the top tracks versus the blur in the lower ones, I'm guessing that the top ones came first. I know that's tricky business in the sandy soil there though, because just a little difference in wind exposure will degrade one set of tracks much faster than the other.
Did you mean "based on the clear definition in the top tracks..." that the top one was more recent (rather than came first)?
I've got to admit that the aging here is difficult, it might be helpful to click on the image to enlarge it if you are having trouble. Even then you may need to do a little speculating.
Anyone have any thoughts as to what gait this might be in? Tricky with the limited view, but what are the options?
Thanks for pointing out the pebbly texture, I didn't notice that feature, but focused on the marks left by what seem to be rather stiff modified hairs. Decided that the upper track looked like those of a porcupine. I also decided that they were there first (after the truck) because on the far left one of the upper tracks looks like it was obscured by the lower track. I'm still thinking about the lower track. Seems like the shape of the pad in the track on the far right should be helpful. I decided that the toes don't look splayed out enough to be a domestic canid, but I'm not sure about that decision.
As the picture sits, I would put the tire being the first, made in dry sand, moving from right to left. The dorsatum is next, moving from left to right in a direct register, diagonal walk, which is faster than the normal pace of this wide-bodied animal. (I'm not going to talk about gender or actions in this one.) The vulpes (probably fulva) is also moving from left to right, and it looks like probably a slow lope, which is also a little quicker than the normal direct register trot and walk that they use in more secure territory. I would imagine that since the animals are moving in a common trail, also used by humans, that they are being much more cautious. I put the dorsatum tracks at night, particularly because of the clarity from moisture that settles in the sand when the days are warmer than the nights. I put vulpes later after sunrise when the sand has warmed. There must be water close by, too. I would venture a guess that the animals were moving westward if the photos were taken between eleven a.m. and one p.m., but that's a stretch.
I put the dorsatum first because the vulpes track actually is made when the sand was warmer and drier, plus the degredation of the track edges is more prominent in the dorsatum, as they appear rounder, but the vulpes rear track on the left seems to have collapsed the claw-drag of the dorsatum, and there is no sweep, nor edge destruction of the vulpes track by "stiff hair" drag.
Are you basing your identification of Vulpes on size and habitat like Deanna, or do you have some additional characteristics your using?
Do you think an overstep walk could be a possibility on the canine tracks, or does anyone notice something that might recommend against that?
I like the observations and analysis going on here. The moisture stuff is really interesting to me as I began to notice some more of the differences that makes in the aging of tracks not too long ago and still have a fair bit to learn about it.
If you, Quigley (or anyone else), has observations about the gender or actions, I would certainly be interested in hearing them, especially when accompanied by some explanations (as many of the advanced observations were in the first week's comments). Even if I am not at a point now where I can follow the explanations well, they may help me get to that point and be worth coming back to if/when I do get to that point.
I'm basing the vulpes id on the dorsatum track size and the spacing estimation between tracks. Dorsatum tracks are around two-and-a-half inches, and when a foot is pressed into loose sand, the compression shape is larger than the actual track. So vulpes fits in there, but it could be a young coyote, except that it looks like there is a potential of the "bar" across, at least, the middle canine track, if not the one on the far right, as well. I honestly can't discern front from rear tracks from this photo, but size and position seem to dictate that the middle is a front, while the outside tracks are hinds.
I also can't say whether this is a swift fox or a red fox specifically. Both animals have overlapping territory with dorsatum, and I can't make out any particular indicators of location. I cannot see an indicator of the gender on the canine. I cannot see a clear indicator of gender on the dorsatum, either, but I would venture to guess "male" based upon what could be the indicator in the heel. (My instructor calls them Movement Indicators, not Pressure Releases.)
The heel of the left-most canine track is also not clear, but I believe that the dorsatum claw drag walls did fall into the later canine track. It's a shot, but with the edges of the canine track appearing to be undisturbed by quill drag, I have to stick with it.
I think an overstep walk is a distinct possibility because there is no apparent cast-off or wake at the rear and forward edges of the canine tracks. I have a hard time estimating stride distance like this, but it would mean that the two front feet can't be more than about fourteen, maybe sixteen inches apart, which is possible. There is also right drift indicated in the canine tracks on the right walls, meaning that the animal was leaning in that direction, as if wind was blowing at its left side, or as if the land is sloped downward (toward the bottom of the photo). I'm used to seeing the more "in-line" track alignment for a fox, so the juxtaposition and what appears to be two hinds and a front made me jump to "lope".
I was figuring a westward movement based upon the shadow in the tracks being pretty shallow, which would put the sun pretty high in a more southern position, which would make the direction of travel westward or maybe northwestward.
The weight range can overlap between the two animals, so it makes me think that the dorsatum must have been moving during a time when the sand was more firm. The detail in the dorsatum tracks is either due to moisture or fine, powdery sand. The vulpes, however, obviously caved-in loose sand, which puts it most likely during the day or early evening. If it is a lope, though, the vulpes could have moved through around the same time as the dorsatum, but I don't think so.
As far as the canine, there's no way for me to be certain of vulpes. It could be someone's terrier for all I can tell. It's just that the tracks seem to show vulpes characteristics.
Just to clarify that right drift in the canine tracks... If the wind was pushing the animal from the left, I would imagine the dorsatum tracks would be pretty abused, and they are not. The land could slope, but I think it's just a movement influence, as if the animal was shifting direction to its right. A lope would explain the wall pressure better, but given the looseness of the sand, an overstep walk still makes sense, too.
OMG. I guess an "indicator of location" might be the caption over the photo that says, "...central Washington." Woops.
Yeah, that might be a good indicator :)
Also from peoples comments I'm not sure if anyone noticed the small ruler in the upper left of the picture. It is slightly longer than three inches in total length which might be useful in estimating track and stride length.
These are clearly the tracks of a spadefooted toad on the top and an elephant on the bottom. The micro pressure releases in the third claw of the top animal and the anterior sub-lope on the interdigital pad of the bottom animal could be left by none other than these creatures....
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