Winter Tracking Opportunities & Mammal Systematics.....

One of the great things about winter is that it provides lots of tracking opportunities.

We finally got some snow here this January.  December had been, basically, snow-less....which was sort of a disappointment.  However, the new winter wonderland this month gave me a chance to get outside with my daughter and follow some of the trails in the woods just behind the house.

Basically, all of these tracking opportunities near the house involve the ubiquitous white-tailed deer, but that's alright...especially when your with a three year old that can't walk too far from the back porch in her giant puffy snow suit.

Last week, the snow in the orchard near our house was a criss-cross of deer trails, all varying in their "freshness".  They lead off in several directions, but most followed a specific pathway through the woods behind the house.  One these trails looked is if it had been made recently.  It branched off of the main corridor and moved through the rows of planted pinetrees along the border of the orchard. 

Above: the main deer trail I decided to follow.

So in the amount of time I had available (dictated by my tracking partner), this easy (and very obvious) trail seemed like a good one to follow.  From what I could tell, the tracks looked like they had been made by a male, but I couldn't be certain.  They were of a decent size with very obvious dew claw imprints on many of the tracks I found.

Above, one of the tracks that actually showed up OK in the deep snow!

The trail wandered along a lane next to the pine rows and stopped to paw at an area in the snow that I had identified as a buck "scrape" during the rut this last fall.  Here it stopped and stamped around, pawing at the old scrape for a bit, perhaps hoping to catch a whiff of some useful information.  This may have also been another spot where a deer previously laid down for the night and another came along later and pawed at it....hard to know for sure.

Above 2 pics: two shots of the old scrape this deer had cleared off (close up shot below, further back vantage above).

It then took a few steps and deposited a little bit of fresh scat.  A signal to others?  It wasn't left on top of the scrape it had been stomping at, but nearby, so I'm not sure.  It may have just been "time to go", if you know what I mean. 

It also took an opportunity to peel some bark off of a few small trees......

Above 2 pics: Two great example of a scrape made by a white-tailed deer's incisors as it stripped bark from this little tree

Most members of the Order Artiodactyla* have no upper incisors.... only lower incisors.  Extant global Families listed by Mathee et al. (2001) within this Order include:

• Family Camelidae (the camels)
• Family Suidae (the pigs)
• Family Tayassuidae (the peccaries)
• Family Hippopotamidae (hippos)
• Fmily Tragulidae (the small "mouse deers" or chevrotains)
• Family Moschidae ("musk deer")
• Family Cervidae (deer/elk/moose, etc.)
• Family Bovidae (cattle, buffalo, sheep, etc.)
• Family Antilocapridae (pronghorns)
• Family Giraffidae (Giraffes)

Cetaceans (Dolphins, Whales, Porpoises) as a group are also positioned somewhere in the Order Artiodactyla, but listed as a "Clade"....I think.  The Clade Cetacea has its own list of families (such as Family Balaenidae for baleen whales, etc.).  Cetaceans are apparently most closely related to the Hippos among any of the extant Artiodactyls (Gatesy 1997; Price et al. 2005).  There may have been updates to this that have occurred since Price et al. did their work.  Mammalian phylogenetics can be pretty confusing these days.  I'm not as up on my mammal systematics as I should be I suppose.

Regardles of the systematics.......of these Families within Artiodactyla, only the pigs, the peccaries, the hippos, and the Cetaceans have upper incisors.  The rest, such as the deer/elk/moose, etc. (Family Cervidae), Pronghorn (Family Antilocapridae), and the cows/sheep/bison, and so on, all have no upper incisor..but ONLY lower incisors.

Yet, these lower incisors are used to great effect when stripping bark off of trees.  They can take those very sharp teeth on the lower jaw and run them up underneath the bark of a tree (especially a young tree).   They then scrape with an upward movement of their head and strip the bark off for quick meal.  You can actually see the incisor marks in the first picture above.
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After following the trail a short while longer, I came across an area where the deer decided to rest for the night.  It was a perfect spot.  Located below some large pine boughs, so protected from further snowfall and wind.  The location was also positioned on a slight incline, looking down over the orchard to the south.  A great vantage point to see, hear and smell what might be coming up the hill towards him.

Above: the "lay" that this deer made when he decided to bed down below some pine boughs for the night.

And then...finally....my daughter had had enough tromping through the snow, and we started heading towards the back deck.

But, it's nice to have these little opportunities from time to time..........
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* Cetartiodactyla is apparently an alternative Order name that has been proposed for Artiodactyla (Price et al. 2005).  I've seen it a few times....and I'm not fully certain if it's accepted yet or not?  Maybe someone can enlighten me.

Literature Cited

Gatesy, J. 1997. More DNA support for a Cetacea/Hippopotamidae clade: the blood-clotting protein gene gamma-fibrinogen.  Molecular Biology & Evolution. 14:537-543.

Matthee, C.A., J.D. Burzlaff, J.F. Taylor, and S.K. Davis. 2001. Mining the mammalian genome for Artiodactyl systematics.  Systematic Biology 50:367-390.

Price, S.A., O.R.P. Bininda-Emonds, and J.L. Gittleman. 2005. A complete phylogeny of the whales, dolphins and even-toed hoofed mammals (Cetartiodactyla). Biological Reviews 80:445-473.