The Royal Buzz
As winter begins to loosen her grip in North America, bumblebees emerge from deep underground. These mated females, known as queens, are the only survivors from last year's colonies. They search for pollen to nourish their developing broods. One wildflower that they seek is the shootingstar, an early bloomer that yields large amounts of pollen -- but only to the insects that know how to get it.
Eastern Shootingstar
© Jessie M. HarrisWhen a bumblebee approaches a downward-hanging shootingstar, she grasps the flower tightly with her feet and jaws. She then curls her abdomen around the opening and begins to "buzz" her large flight muscles. The vibrations she sends through the flower (about 300 cycles per second) dislodge the pollen from within the anthers, and it pours out through tiny holes. The technique is known as buzz pollination. If you see a bumblebee working her way through a group of shootingstars, stop and listen -- you will clearly hear the pronounced buzz as she pauses at each flower.
To learn more about bumblebees, click here.
Life beneath the Snow
Long-tailed Weasel
© Robert E. Barber
Next time you gaze out at an expanse of snow, consider what may be happening beneath the placid surface. In the gap between the snow and the ground beneath -- a space called the subnivean zone -- an active, unseen world unfolds. The space is formed when the unfrozen ground melts the snow above it. Water vapor condenses and freezes on the undersurface of the snow, forming a solid ceiling. The air in this space remains just above freezing, even when outside temperatures dip below zero. Small mammals such as mice, pocket gophers, and voles remain active throughout the winter in the subnivean zone, feeding on grasses, seeds, and tender sprouts. Some of these rodents are highly territorial in spring and summer, but during the winter they will tolerate members of their own species and may even form communal nests under the snow, benefiting from the effects of combined body heat.Although invisible from the surface, subnivean rodents are still subject to predation from above and below. Weasels hunt beneath the snow, as does their larger relative, the American Marten. Large predators such as Coyotes, foxes, and owls use their keen hearing to detect activity under the snow; they then pounce through the surface to capture unsuspecting prey.
Click here to see a picture of a Southern Red-backed Vole.
Ask an Expert: Mated for Life?
Tundra Swan
© Herbert Clarke
Q. I have read that Wolves, Eagles, and Swans mate for life. Are there other species that do this?A. There are many birds that form long term monogamous bonds. Because both parents often cooperatively care for young, monogamy is practical for those species. Once a good partner has been located, there is a strong tendency to remain together, rather than expend energy each season seeking and courting another mate. However, when biologists look at the offspring of many so called monogamous species, there is evidence that the female has mated with more than one male.
Upon close examination of species that supposedly mate for life, it turns out that they are about as monogamous as humans; more than 50% end up with a different partner. Wolves, like a few other social mammals do indeed form long tern pair bonds, but they usually mate with other individuals in the group.
To learn more about the Gray Wolf, click here.
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