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.
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”.)
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.