More on Teeth and Feathers

I asked my tracking mentors to look over the Turkey Tale post and tell me what they thought.  A couple of them commented on that post directly, adding some great information.  Another (also named Dan) sent me an email and I asked if I could share it here to show how the process of discussion among Naturalists works.

Great story, man…engaging, inspiring, great role modeling for mentoring, tracking, and follow-up research.

Technically – looks good with the exception of one line that stood out to me – the one about canid vs felid carnassials. It’s incorrect.

Check out this paper to learn why:

http://www.mun.ca/biology/scarr/4505_Felid_Teeth.htm

Thanks for asking, Andy.

dg

My reply

Thanks for the paper and the complements.

I got that info about the teeth from Elbroch. In Mammal Tracks pg 737-8 he says “Bobcats, which have less developed carnassail teeth than canines do, leave much more ragged sign… The appearance is one of chewing through feathers rather than cleanly shearing them.”

Do you think the observation of “more ragged sign” etc is incorrect or could something else account for that appearance. I agree after now looking closely at some pictures of bobcat skulls that the carnassials look pretty well developed. Have you encountered any large bird eaten by a bobcat in the field? How were the feathers dealt with?

I enjoy the back and forth of question and discovery. If anyone has experience with mammalian predation of birds please add your two cents in the comments section.

 

Below is what I felt was the most pertinent part of the paper Dan mentioned.  There is more in this interesting paper on the evolution of felid teeth, see the link above.

If we examine the cheek teeth of a typical cat, whether it be a lion or a domestic tabby, we see that by far the most important feature is the scissorslike arrangement of the upper and lower carnassials, the meat-slicers. This arrangement is enhanced by the fact that the articulation for the mandible or lower jaw, the hinge, is in line with the intersection between the carnassials, just as in a pair of scissors. The other premolar teeth, although by no means unimportant to the animal, are relatively less significant. When we examine the cheek teeth of a saber-tooth such as Homotherium latidens, a species fairly common in Europe around 1.0 Ma ago, we see an even greater specialization in slicing, with the anterior check teeth much reduced in size.

The dogs have carnassials too, but they are only part of a dental armory that is augmented by many more premolars in front of the carnassials and by the crushing molars behind them. The dog is therefore a generalist when it comes to food-processing ability. In the hyenas the specialization is in almost entirely the opposite direction to the cats, with the development of huge, conical, bone-cracking teeth. Spotted hyenas in Africa today are capable of eating the entire carcass of a zebra, bones and all, but even they retain the carnassials to permit them to slice meat and other softer tissues.

Copied from M. Anton and A. Turner (1997). The Big Cats and their fossil relatives. New York: Columbia Univ. Press. I present it here in good faith to add to this discussion and educate my students and followers of this blog.  If the university or the authors wish I will gladly remove the quote in favor of a link to the information.

New Spot for the Camera Trap

Eastern Coyote in camera trap

We finally set up the camera trap here in Northfield.  Deneen and I put it out near one of her sit spots.  It is pointed at a well used trail but I poo pooed the spot because the trigger is slow and animals (and people) moving down a trail often do not get captured in the image.  Well as you can see I was wrong.  Great shots of a coyote, deer and in the last picture, the tail end of a bobcat.

Good to get reacquainted with the neighbors.

eastern coyote in game camera coyote in camera trap deer on game camera Bobcat on camera trap

Bobcat Scent Marking Behavior

Bobcat Track in Snow

In an area known as Catlin Woods in White Memorial we came across this Bobcat trail.  Scent mark

Upon following it we found many scent markings.  It seemed to go from one to another, not more than a couple dozen yards apart.  I never think to measure or count these things but there were at least 7 or 8 within 75 yards or so.

Below is a nice section of a walking pattern.  Bobcats will often use an overstep walk as well as this direct registering walking pattern.  You can really see the wideness of the trail here, indicating the wide body of the animal.  A fox walking leaves a much narrower trail in proportion to its tracks and stride (length between each step).

Bobcat walk tracks

Bobcat Scent Marking

As evidenced by these tracks the animal would aim its back end at a stump or log and spray it with scent.  When we put our noses to it there was a definite catty musk.

Bobcat Scent Post

Even though the spray seems to have come out the back side it is my understanding that does not contraindicate a male.  The size of the tracks and frequency of marking lead me to believe is was indeed a male, though I cannot be certain.

Bobcat Marking Territory

Wrens and Animal Tracks

Opossum Tracks in Snow

On a short walk New Years Day I came across the tracks of an Opossum also taking a short walk.  Opossum don’t like deep snow and this one did not spend much time in it, coming out only to circle around the pile of construction debris it seems to be wintering under.

Opossum Tracks in Snow

The picture above shows a good front foot track.

While looking at the tracks I heard what at first sounded a lot like a tree frog, a loud twittering call coming closer.  I am not an experienced birder so was eager to see who the sound was attached to.  This little Carolina Wren (or so I identified it as, please correct me if I am wrong) came right up to me singing away.  It changed its song from the twitter to several other call like sounds which may have been alarms or scolding calls at me.

Carolina Wren

I had been scolded before by a pair of wrens at my old sit spot so was expecting this one’s partner to come along to check me out as before.  When the bird pictured below showed up seconds after the first one left I assumed in my ignorance it was the mate of the first.  It had a different call but I assumed that it was the female and had a less flashy vocalization.

Turns out it was a different species altogether, Winter Wren. They were the only birds I saw that day.

Winter Wren

In the woods were some Bobcat tracks.

Bobcat Track in Snow Bobcat Trail

And these turkey tracks.

Wild Turkey Tracks In Snow

They are quite “K” shaped.  That shape is usually ascribed to Zygodactyl footed birds like Owl’s and (at least some) Woodpeckers.  This created some doubt for me but shortly I found long strides over a great distance, something only a ground bird would leave behind.

Turkey Tracks in Snow

Bobcat and Coyote Tracks

Coyote Urine

The sun a snow were great again yesterday.  I saw many tracks of coyote and bobcat as well as mice and squirrels.  Most were older.  Above and below is a coyote’s scent mark on a raised area of snow.

Coyote Urine

Below a bobcat trail moving from above.  The animal moved from boulder to boulder exploring under and around them.  I have seen bobcat sign here many times, once a spot where the animal laid up among the boulders of this ridge.

Bobcat Hunting

More Camera Trap Pictures From the Deer Carcass

Game Camera

More pictures from the game camera.  This Eastern Coyote came.  Seems to be a different individual than the other coyote in previous photos.  Neither coyote fed.

It started to snow around 5 am while the Coyote was there.  Then this Bobcat (which I later determined to be a male, both bigger and lighter colored than the other Bobcat) came to the carcass.  It immediately covered the carcass with leaves and eventually fed from it.

We had removed the hide in order to take some meat for ourselves and then placed the rest of it here with the hide back on.  Our manipulation of the hide may have effected the way the animals feed from the carcass.  The Bobcat started here at the shoulder then moved to the rear end.

He looked over his shoulder many times toward the field.

Early that night and again the next morning the first Coyote came back.  I have the pictures in opposite order here because it’s a pain to change it.

On the thirteenth both male and female Bobcats are on the carcass when one of the Coyotes come in.  I wonder why it waited until now to eat from the carcass?  There were plenty of opportunities when no one else was around.

The female was much less comfortable with the Coyote and was never in the picture when the Coyote was close.  The male however would not leave the carcass.  I have many more pictures of the Coyote and male Bobcat together like this.

Here are the two Bobcats eating peacefully together.

More to come.

Deer carcass visitors on camera

I placed a smallish road killed deer in front of our game camera in a high wildlife traffic area. In this and posts to come I will document what animals came to investigate and feed off of the carcass. As you will see by looking at the dates and times on the bottom of the pictures it was there for a while before anything but birds actually ate from it. The coyote seemed particularly shy, maybe do the the flash of the camera. Evidently they all got used to it after a while.

Placing deer carcass

Thats us carrying it out in front of cameras former position.  It will be moved 20 yards or so into the woods from this position.

Crows

No disturbance the first night.  Crows come the next day, eventually many of them every day.

Vulture
First vulture

Vultures come on day 2 and are present until 11 am.  Nothing has visited on night 2.

Vultures arrive
Raccoon visits carcass

The first night time visitor is on night 3 when a Raccoon shows up but does not feed from carcass.  Some crows come around the following day, day 3.

Shy Coyote

On night 4 a shy Eastern Coyote comes by and from 11:06 to 11:10 moves in and out but does not feed from the carcass.  We found this strange.  I have read that coyotes become suspicious of bait placed by humans if they have experienced trapping but have know reason to believe there has ever been trapping in the area.  The coyotes here, probably this very one, has eaten the suit I have put out in the past using my bare hands and must be familiar with my scent and humans in general.  All this is taking place in a patchy rural and suburban landscape.

Coyote
Red Tailed Hawk scavenges

Day 4 a Red Tailed Hawk comes on the scene.  I did not know them for scavengers but it comes at least twice on this day feeding.

Red Tailed Hawk
White Tailed Deer investigates carcass of another Deer

Night 4, 2 Deer come.  This made me feel bad.

Female Bobcat shows up at Deer carcass

Now things start getting interesting.  Closer to dawn on night 4 our resident female Bobcat gives it a sniff but does not feed yet.  In the next post you will see more of this animal and other large predators get down to business.

Bobcat hunting lay and Coyote pack gathering.

 Bobcat trail up under the powerlines near my house.  If you look deep into the track you can see the asymmetry typical of the felines. 

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 I followed him ( I think it was a hime because of the size of the tracks and stride of the trail), up the hillside and found this spot.  He entered from the left, the fanlike impressions toward the top of picture are from its front feet and forlegs as it moved back and forth changing is view. 

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Bobcats and other felines hunt very much like humans do, using stealth and their sense of site and hearing to locate prey.  This requires stopping often to look and listen, in this case the bobcat created what is called a hunting lay where he sat for a long period of time watching the hillside from above for any prey.  Below is a picture from the Bobcats vantage. 

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At the top of the hill just above the Bobcat’s hunting lay, I found these tracks of some Coyotes gathering in there nightly rendezvous.  I have heard the pack howling to each other many times in the night coming together to reinforce family bonds and share in the hunt.  As you can see in the picture below they are not shy about partying near human habitation.

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These prints where just steps from the gathering spot pictured lower down.  I had seen tracks such as these before near pack gathering places and did not quite have the confidence to call them what I believe they are.  I have seen them enough now that I am willing to say it is the spot where the initiating Coyote stood to begin the howling after which the others would have answered and then headed to the spot.  The animal came in from the left leaving tracks of its front feet once then again to the right in pairs.  The added depth of the pair of tracks furthest to the right suggest a lingering and shifting of weight.  I take this as signs of its raising its head and straining with the emotion of its song.   Upon hearing one of its comrades aproach from behind it turned around to meet it. 

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This is looking back toward the direction of the Bobcat lay.  To the right is the gathering spot where the Coyotes greeted each other, testing pack hierarchies with posturing and muzzle licking and maybe some good natured romping. 

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 Adjacent is a scent marking, something I see with each of these gatherings, part of the complex visual, olfactory and vocal comunication system these neighbors of mine use amungst themselves and for the benifit of strangers.   Look close and don’t eat the yellow snow. 

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Big Bobcat

I am finally posting again, sorry for the interruptions I will try to post more regularly or at least in bigger clumps.

Yesterday on the way to work I saw a huge bobcat in the middle of the day in someones front yard. I was driving, late for work and going to fast but still saw it from the corner of my eye right there in the sunshine. It was so big my very first thought was I was seeing a mountain lion. Of course it was not, it had pointed ears with white spots on them. It was as big as a smallish German Shepard, very healthy looking and moved rather slowly. I slowed down as I went past and had to back up. I do this a lot with wild animals and they often wait for me to come back for a second look, I assume out of curiosity. I had my camera right there on the seat next to me but by the time I got it out of the bag the bobcat had walked into the woods. I got out to look for it, but of course it disappeared like a ghost. When I went back to the car it appeared crossing the road in front of me. I got a couple crappy pictures of it that I will try to put up next week when I get back home.

I can see how people may sometimes mistake bobcats for mountain lions, though I am sure that is not always the case. I can also understand now how a bobcat can hunt whitetails, this animal was certainly capable of taking doe.

Andy