Naturespeak A naturalist's view of the world

January 24, 2013

Leave it to Castor – Part 3:Tails & Tots

Filed under: Uncategorized — wykes @ 7:50 pm

The Conners Creek beavers did not leave much to the imagination. Over the course of two days of observation they shared (willingly or not) most of their lifestyle secrets. They seemed so at ease with my presence that I held out hope that they would eventually reveal whether there were any young beaverlets hanging about. I am a fairly trustworthy-looking fellow and most parents do allow me near their children. I did my level best to look “beaver friendly” and was rewarded.

Earlier in the season, one of the Edison Boat Club members told me that he had seen one of the beavers with a baby riding on her back as she was swimming. She was carting her young down the canal in close vicinity to the boats. Because beaver babies do frequently hitch piggyback rides with their parents, my response was “really!” as opposed to “really?” In other words, I needed no convincing. I trust you can see by now that these creatures never cease to be a source of continual amazement (I am, of course, talking about beavers and not boat owners).

By the time November rolled around I wasn’t expecting to see such piggy-backing babies anymore. The young, if there were any, would be quite large by now. Michigan Beavers, aka “kits”, are typically born between late April and late June. They come into the world with a full coat of hair and open eyes (precocial) and are about the size and weight of a Coke can (slightly heavier, but not much). Given a good upbringing and all that, a healthy offspring could be expected to weigh around 10 pounds in November.

One b-child did appear soon after I arrived on the second visit (see above and compare with adult portrait at the beginning). Frankly, it was a fair sized critter and I would not have known it was a young’n had it not been accompanied by an escort of two very large adults. It was a matter of scale. To one accustomed to watching muskrats any beaver looks gigantic. Apart from being smaller, this kit was also fuzzier and rustier in appearance than its parents.  I only saw this one individual the whole time, or at least I thought I did.  You see, an average litter would normally consist of 3 or 4 kits. Perhaps only one opted to show its face on this occasion or only one came out at a time or, indeed, this was a privileged “only child.”  At any rate, I’m calling this a three beaver bunch.

The trio mulled around for a bit in front of the lodge and this little one stayed very close to “mom” the whole time. Again, I remind you that it is impossible to tell a mom from a dad based on appearances so it is a bit sexist to say “mom” in this case but so what.  After a short spin the kit hitched a ride with the mother-unit as they slid past me (see here). Being too large for a back ride, this little fellow appeared to place a paw on the tail and held on as if it were a surf board.

Mom eventually dove and re-surfaced some 12 feet away and junior did the same after hovering for a few anxious moments – eyes fixed in my direction.  The beavers were showing some impatience with me by this time. During a lull in activity, after the last visible beaver had departed down the canal toward the Detroit River, I ventured over to the lodge side of the canal and momentarily stood on the lodge itself. This was obviously a breach of etiquette and the clan let me know it.

When the departed beaver (dearly departed beaver) returned after a few minutes to find me standing on the roof it performed yet another classic move by striking the water with an explosive slap of the tail before diving.  In beaverspeak this loud and flashy maneuver signals a general alarm.  I quickly retreated and the crew soon settled back into its normal “busy as a beaver” pace.

Later I took a look at movie of this alarm sequence and noticed a few peculiarities worth passing on for the sake of animal behaviorists everywhere. In the video sequence tracking the advance of the “alarmed” beaver, the animal had its snout and head high out of the water. You can track the increasing state of alarm as the relatively calm creature approached and gradually brought its head higher out of the water (see above).

While the final move of this sequence appeared to be strictly a tail thing, review of the action shows that there were two things going on (see above). The head is forcibly plunged under at the same time the tail strikes the water thus creating a double splash. That famous beaver alarm sound is actually a “ker-splash” rather than just a “splash.” Fascinating? Well, I’ll leave that one to you. If nothing else, I’ve proven that Beavers aren’t just for Canadians!

I opted to leave these northern symbols alone for the winter and hope to return a few more times as spring approaches.  School is out for now.

1 Comment »

  1. article in the freepress about the return of beavers …

    Comment by j — March 18, 2013 @ 1:02 pm

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