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.

January 13, 2013

Honeybee Hide-a-way

Filed under: Uncategorized — wykes @ 3:43 pm

I have rarely been stung by honeybees over the course of my life so I can remember the circumstances of each incident. The first was when I undertook an ill-fated adventure to collect some bees in my front yard. I decided to pick them off the clovers with my fat little fingers and throw them into my red little wagon. Needless to say, one of my fingers got even fatter (and redder) when I was stung and the affair quickly ended in tears. I was well under 5 years old at the time, so let’s not be too critical.

The second time was in mid-winter.  The frozen ground allowed the Willow Metropark Golf course crew to get access to a decrepit old tree that needed to be cut down. Once felled, the large trunk cavity broke open to reveal a large colony of wild honeybees. Like so many Poo Bears, we started to collect the golden honey-laden combs. The bees were alive, but they were moving so slowly that they were easily brushed off. One bee did find its way into the space between my neck and coat collar, however, and zinged me.  Many of them started flying about in short order and we beat a hasty retreat in our big red wagon.

I was around 22-23 years old at the time of that second sting story and probably should have been more careful, but one can be excused for assuming that February bees would take a very long time to warm up. The truth, as I learned then and now know, is that wintering bees are not like other wintering insects. In other words, they are “on” all the time.

Honeybees do not hibernate. They huddle, cluster, shiver, and eat their way through the cold season but never enter a state anywhere near sleep (or diapause as insect hibernation is called). As long as the security of their hive and their food supply holds out, a colony of bees will successfully survive into spring. Any beekeeper worth his honey will tell you this.  They also will tell you how much they worry about the winter success of their domestic bees.

I am not a beekeeper, per se, but my attention is being kept by a wild bee colony which took up residence in one of my backyard maples late last summer (see above views).  Utilizing a cavity which had previously been used by a pair demonic Red Squirrels, the …or shall we call them “my” – colony immediately set about retro-fitting the place and putting  up honey stores. One of the most obvious tasks was limiting the size of the entrance hole by filling in with a varnish-like substance called propolis, aka “bee glue.” Consider this a type of Bondo for bees.

Based on the winter view of that hive, it looks like the colony performed the mechanical part of their task with collective skill. The shiny propolis lining the entrance is easily visible (see below). There is no good way for me to ascertain if the group put away a sufficient stock of honey, however.  Now that the hard part of winter is upon us, I am feeling some ownership (worry) over the success of this hive.

It is best to think about a winter bee colony as a super-organism which functions as one body. In fact, it’s not too silly to say that they act downright mammalian (they bee mammals?). The colony maintains a consistent core temperature of around 80 degrees or so. They cluster together into a tight huddle, with the queen positioned at the center, and shiver. This muscular action generates a tremendous amount of heat. Individual bees will rotate from the center to the outside in order to distribute the love.  Even the outside of the cluster will be well above freezing. Thermograph images of a winter honey bee clusters clearly show the temperature gradient running from close to 90 degrees F to 40 degree F. while the ambient air temperature is well below freezing.

It takes about 30-50 pounds of honey In order to keep this kind of group hug going all winter long. It is worth noting that the winter bees are of stouter stock than the summer bees – they are fatter, larger and longer lived. These beefy bees are constantly consuming their honey and pollen stores in order to keep their energy levels up.  I can have no way of knowing if “my” bees have enough supply to make it, but they did recently show me that they were still a viable colony…at least so far.

Perhaps you hadn’t thought about it before, but with all that shaking and eating going on the bees will eventually have to take a pee (as in B P P).  On days when the temperature climb above freezing, individual bees will take a brief outside flight in order to relieve themselves. The flight is short but effective. Some of the weaker insects do not make it back and these remain still and cold on the snow crust.

There are occasionally a few dead bees scattered on the snow below the tree hole but these are quickly eaten by wandering flocks of Juncos, Cardinals, and various Sparrow species. Because I no longer have my little red wagon, I do not endeavor to collect these yard bees. The warmer days of this past week have provided extended potty breaks for members of the hive. When the afternoon temperatures soared to the upper 40’s the hive entrance was abuzz with winter bees seeking relief.

January 5, 2013

Leave it to Castor – Part II: Look Ma I’m Walking

Filed under: Uncategorized — wykes @ 2:47 pm

In spite of their novel urban setting, the Conners Creek beavers behaved as if they were in the middle of the Canadian wilderness (as far as I know). The label “Urban Beaver,” while potentially evoking images of street-wise rodents picking up fresh bark peelings from the Eastern Market or eating left-over shish kabob sticks in Greektown, is meaningless.  I assume wild Canadian Beavers carry mud to their lodges, store cuttings underwater, and slap out warnings just like the Beavers I observed in the “D”.  These were beavers – neither urban nor rural – just beavers doing their thing.

I didn’t expect the beavers to be active after the arrival of daylight so I arrived well before sunrise on my first visit. The spot-lighted stacks of the Conners Creek Power Plant glowed like two tremendous light sabers and cast a bright refection on the canal next to the lodge. As expected, I soon spotted shady forms moving about in the light-sparkled water and was excited to “see” them coming and going. As the sun rose I could actually “see” these creatures.  Since they could now see me as well, I expected they would start to get shy. I could not have been more wrong.

As if on cue, waiting until it was light enough for me to take some videos, one of them emerged out of the water with a stick in his mouth and carefully placed it. The event had an OCD component to it. After returning to the water the same animal re-emerged at the base of the lodge carrying an armload of mud. It walked upright like a small human and plodded up the slope with its cargo held tightly under the chin with the front legs. It dumped the load with workmanlike precision, pushed the wet pile into place, turned around, and walked on all fours back to the water.  Several other loads, similarly delivered on two legs, transported a load of water plants and a mixture of mud and sticks.

A written description can hardly capture this most amazing of beaver behaviors, so I have included a video. There is no soundtrack, but you can include your own mental version of “Whistle While You Work” for effect.  In 1698 a mapmaker by the name of Nicholas De Fer presented a largely imaginary scene of a colony of beavers working on a dam. He showed a line of beavers walking upright with bundles of sticks in their hands like so many merry elves. It looks comical by today’s standards but, apart from the details (like carrying bundles over one shoulder and walking in a line) this part of De Fer’s image is remarkably correct.

De Fer, in that same engraving, also shows beavers carrying rocks on their tails but we’ll have to ignore that one. Beavers do not drag materials in that manner.  Speaking of tails, however, you’ll note that the beaver shown in my pictures had a large notch in its appendage which made it easy to identify. This was the only individual which performed lodge duty. Perhaps it was a union thing?

Old “Notch” then demonstrated how to drag a tree into the water. After dumping the last load of water plants he walked over the top of the lodge and latched onto the trunk of a small freshly downed Cottonwood. Gripping it near the cut end with his powerful jaws he dragged it down the sloping face and into the canal.  Finally he dove, taking the entire tree with him, and wedged the trunk into the canal bottom adjacent to the lodge.

If this were a PBS nature show, the accented voice of the narrator would explain that “Like all beavers, Notch was building up a food supply for the winter by creating an underwater stockpile of branches. Beavers don’t eat wood; they are bark eaters which will depend on this supply to get them through the long northern winters.”  Of course, they would then show an underwater view of the beaver placing the branch into the food cache. I was not able to do that because my camera is not cleared for water duty, but you can imagine that part when you view my video.

Our imaginary accented narrator would have brought up an important point, however. Beavers chew wood in order to fell trees. They do not eat it. Those trees with non-palatable bark are used to build dams and lodges. Willows, poplars and cottonwoods – trees with tasty bark – are neatly cleaned of their bark before they are used for building. There was plenty of evidence about the Conners Creek lodge for both activities. A hungry beaver can strip off the bark layer of a branch with incredible precision.

My next visit to the Conner Creek Castor Casa revealed even more fascinating details of beaver life and I’ll cover that in Part III (Return of the Castor). Fortunately, upon learning that these critters were not night owls, I was able to sleep in before embarking on my next visit. That was a slight beaver joke, by the way: embark as in bark as in not that funny but still a good way to end a piece. Perhaps if I had stated that with a slight English accent it wood have gone over better.

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