On the tracks of otters

These are otter prints.  The animal has been bounding along (diagonally left to right in the photo) using the typical bendy movement it shares with its cousins the weasel and the stoat. 

What you see are characteristic clusters of four separate footprints.  First, the left and right front paws hit the ground  slightly out of sync and one in front of the other. As the otter's momentum carries it forward, the body moves over these two prints until the two back paws plonk down beside marks left by the front feet. 

As followers of my previous tracking posts will have guessed by now, I applied my usual techniques of skill and field craft to work this out - which is to say, none whatsoever.  I watched the otter bound by and then went up and had a shufty at the tracks. 

Here is the first bit - front paws hitting the ground, one at the back, the other further forward.  The back legs start to move through.

Then , kerplonk, down go the back feet right beside the front feet  marks but managing not to overlap any of them.

The push off given by the back legs together with its forward momentum, propel the animal quite a way forward such that the next time the front feet hit the ground the animal is far enough away to register a separate and distinct group of four.

With an otter of this size moving at a reasonable pace but not full tilt there is about 9 to 10 inches between the groupings.

The sighting of this otter was just one of those fortuitous things that is bound to come along if you spend enough hours outside in the right places.  Apart from a few tracks and signs it had been an otterless week until the last hour of the last day on Colonsay when I decided to wander along the beach to see off the last ten minutes before heading off to the ferry. I looked up in response to a movement and stood riveted as this otter ran along the top of the beach, not 20 yards away.  Jammy or what!

Let me tell you a wee story....

I heard a snippet of a song on the radio once that went something like - 'for every day the sun does rise, a new thing falls upon the eyes'. I never did find out who it was by but the words have stayed with me because they explain perfectly why I find natural history so completely absorbing (to the point of obsession according to my family).  All you have to do is get out and there is always but always something new to puzzle over, marvel at or simply stand and stare at.
But, as most of you who take the trouble to follow my witterings (and thank you for that by the way) are fellow NH bloggers, you know this already so I'll get to my point.  Which is to say.... isn't rabbit urine a bonny colour in the snow?

My curiosity to know why it was bright orange led me to some fascinating wee facts.  Apparently rabbit urine can vary from white to yellow to orange and even red.  How cool is that?  When at the white end of the spectrum this is due to secretion of excess calcium as calcium carbonate crystals which turn the urine thick and creamy. At the red end this is due to excretion of porphyrin pigments derived from the diet.  Yellow urine will also eventually darken in the air through oxidation of the pigments.

So there you have it. Proof that the lyrics of that song are spot on.

On Track

Interpreting tracks is an enjoyable addition to any shore walk and much can be deduced from sand prints. In the first photo, a lesser black backed gull stood and stared for a while, before being disturbed, shedding some dead weight then taking flight by running as it took off, dropping a feather in the process.


By contrast, the photo below is made by a bird that, when disturbed didn't run as it took off but hopped as it flapped, keeping both feet side by side - a cormorant by the size of the prints.

The next example is a pigeon-toed carrion crow, leaving foot prints showing separate pads as well as claw trails in between as it waddled up the beach looking for anything interesting.

And finally, a feeding frenzy of small waders - both dunlin and sanderling - were feeding here on sandhopppers and flies amongst the seaweed.

Developing these Mears-ian tracking skills is of course a slow process requiring long hours of meticulous field observation ......

or

you can do it my way - watch the birds take off then walk up and check out the tracks.