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Archive for February, 2012

Beaver Sign of Spring

2-29-12 Beaver Sign of Spring

Anyone who buys and consumes the pale, relatively tasteless, store-bought tomatoes in the winter, and then, finally, can eat their own garden tomatoes right off the vine, will identify with the winter and spring diets of beavers. While they are locked under the ice, the beavers’ entire winter supply of food is a pile of branches they store at the bottom of the pond near their lodge.  Once the ice on the pond begins to melt, beavers take immediate advantage of any escape holes, enlarging them if need be, in order to make their way to fresh, nutritious food.  While their preferred spring food, herbaceous plants, are not yet up, the fresh cambium of living trees is most likely a welcome change from their water-logged winter food.  It is always fun to come upon signs of their activity when there’s still snow on the ground – it’s one of my favorite signs of spring.   


Snow Flies

It always comes as a surprise to see tiny creatures moving nimbly over the surface of the snow.  However, there are quite a few insects and spiders that do, thanks to the glycerol that they produce in their body fluids that keep them from freezing.  The Snow Fly (Chionea sp.) is wingless, probably because at sub-freezing temperatures, it would be very hard to generate enough energy for maintaining flight muscles.  They (along with other flies, mosquitoes and gnats) do have two vestigial wings called halteres, the little knobs on the fly’s thorax.  They inform true flies about the rotation of their body during flight, and are thought to act as sensory organs for the flightless Snow Flies.  Throughout most of the year Snow Flies can be found in leaf litter, but come winter the adults emerge, mate and lay up to 200 eggs.  The lack of predators such as dragonflies and most insect-eating birds makes winter a relatively safe time for Snow Flies to be out and about.  Their life span is about two months, during which time they drink by pressing their proboscis against the snow, but don’t eat.   (Snow Fly in photograph is a female, measuring less than ½”.)

 


Cedar Waxwing Feather

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Several of the secondary flight feathers (inner wing feathers) of Cedar Waxwings and Bohemian Waxwings possess tiny, brilliant red tips. (As Dale Martin pointed out, there is a bit of white next to the red tips of Bohemian Waxwings’ feathers, but those who guessed either waxwing should take a bow.) These “waxy droplets” give the bird its common name, along with its love of red cedar berries.  These drops of “wax” are actually the widened, flattened ends of the feather shafts.  The color is derived from a carotenoid pigment, astaxanthin, which they get from their diet (cedar fruit and other berries).  Younger birds possess fewer red tips than older birds. Ornithologist Peter Stettenheim conjectures that since the waxwing’s ability to find berries probably improves with age, the number, size and coloration of these tips may indicate the birds’ foraging ability.  Research in the 1980’s indicates that these red tips serve as markers in mating, providing visual clues to potential mates about each other’s age, which correlateswith egg size, clutch size, as well as ability to find and deliver food.  Cedar Waxwings tend to mate with individuals of their own age.  


Mystery Feather

To be identified tomorrow!


Mating Season for Eastern Coyotes

If the increased yelping of eastern coyotes hasn’t caught your attention, you may not be aware that this is the peak of their breeding season. Female coyotes come into estrus once a year, for a period of about 10 days.  For the past two or three months, working up to this, male and female coyotes have been increasing their scent marking.  Occasionally you can find where a female has marked with urine, leaving behind a spot of blood (see photograph).  Eventually she attracts one or more sexually active males, and mating ensues. Something I’ve never witnessed, but would love to, is the howling duet of a pair of coyotes prior to mating.   

 


Sign of Spring – Eastern Chipmunk Sighting

 

Eastern chipmunks are up and out – about three weeks earlier than last year!


Winter Survival Strategy of Flying Squirrels

 

During the winter flying squirrels often huddle together in large communal nests, sometimes with populations numbering over two dozen squirrels, in an effort to keep warm.  Two years ago 22 of these nocturnal creatures spent the majority of the winter in my log cabin, doing just that.  Although flying squirrels do not hibernate, if temperatures become too severe the squirrels will enter a state of torpor until temperatures return to normal.