Wednesday, December 12, 2012

A Birthday Otter?

Normally, I wouldn't submit two blog posts so close to one another, and I have a bunch of exam-writting I should be doing....but this picture astounded me.  I had to post about it quickly.

I checked the cams for one of my research projects this morning, and when I perused the pictures the one below caused me to do a double-take.

I can't be 100% certain, but I'm pretty confident this is a River Otter (Lontra canadensis). 


The wide long tail....the "slicked" back appearance of the fur....and the heavy creases in the pad of that right hind foot.

See an example of an otter rump here.

An example of some otter hind feet here (scroll down).

Your thoughts on this would be much apprecaited!

Why is this so interesting to me?

First of all....I have a fondness for Mustelids....and have always went the extra-mile for pics of them.

Second of all, I've gotten so few opportunities to get pictures of River Otters (see here, here, and here). Furthermore, I've been cam-trapping this property for almost two years with no otters!

Third: this location is high and dry (on a hill surrounded by pine trees and deciduous hardwoods).  The nearest appreciable water body is a small-medium sized stream about 0.32 miles to the west.  Coming to the spot with the camera from that stream would require crossing a county road, some back yards and a corn field.  There is a stormwater retention pond on an industrial property to the south (about 0.12 miles from the camera) but it doesn't strike me as big enough for otters.  It also would require crossing a fairly busy county road.  Just beyond the retention pond is a ditch (0.16 miles from the camera).  Yet, at the point when this ditch is closest to the camera, it's barely a trickle.  As one follows the ditch further south, it begins to widen (~ 0.32 miles from the camera) and eventually reaches the point that it's fed by a small-medium sized creek (0.55 miles from the camera location).

Now, it's no shock that otters can move considerable distances.  Movements of up to 42 km (26 miles) along a stream/river in one day have been reported (Melquist and Hornocker 1983). 

But the picture above would be of an overland movement.

Furthermore, this critter is heading north.  If he/she kept on this trajectory, he would run into a deciduous hardwood forest that is in an early stage of succession (lots of shrubs, etc.) and then move into a fallow grassland/old field.  Beyond this, in all directions are agricultural fields.  To the north or east of this camera, the otter would have to travel 2-3 miles (through agricultural fields) to reach a decent water body again.  Of course, she/he could cut back to the west and hit the stream that runs north-south again (like I said, it's about 0.32 miles from the camera).

However, some digging in the literature revealed that sizeable overland movements are known for River Otters....including treks over mountain ranges!  Magoun and Valkenburg (1977) report new observations (at that time) of River Otters on the north slope of the Brooks Range in Alaska.  This would have required they travel 150-200 km (~93-124 miles) from the places where they had been previously known on the south edge of the range.

Thus, I suppose the little overland movement I observed isn't so suprising.

Regardless, the picture of this critter occurred on my birthday.

So....happy birthday to me!!!


Literature Cited:

Magoun, A.J. and P. Valkenburg. 1977. The River Otter (Lutra canadensis) on the north slope of the Brooks Range, Alaska.  Canadian Field-Naturalist 91:303-305.

Melquist, W.E. and M.G. Hornocker. 1983. Ecology of River Otters in west central Idaho.  Wildlife Monographs no. 83. pp. 3-60.

6 comments:

  1. Sure looks like a river otter to me. Great find!

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  2. I agree. Happy Bday to you! Nice otter... (although I'm no otter id expert!

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  3. Totally an otter! Very cool- love that lope that they do- I can totally see it- the hunched back and the reaching front paw. The tail seems to be pointed right at the camera, so we're looking at the dead on- if the tip was a different color it would be a target- IMO! Happiest of birthdays! I hope I get an otter on MY bday!

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  4. You deserve an otter for your birthday! Thanks for the great posts during the year.

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  5. Thank you very much Jeremy! Back at ya! Cam trapped pics of African species cannot be topped!!! Your blog (and Henry's blog) reminds all of us yanks about what it's like to cam trap where there is true "megafauna"! :)

    And thanks everyone for taking alook at the pic and giving your thoughts!

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  6. Late to the party as usual Trailblazer. First of all, happy very belated birthday! Secondly, I think that is definitely an otter. The tail is in an awkward position, but the foot pad seems to be the identifying key. Great shot and great info about how otters travel. Love it!

    Bill

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