Saturday, October 9, 2010
Saluting an Arctic Pioneer
The Northern Bumblebee, Bombus polaris, can survive on Ellesmere Island in Canada's far northern arctic. This is the farthest north that any true social insect can live. This species is a true northerner, being found in a circular distribution around the arctic, ranging all the way from Alaska, to Greenland, Scandinavia and northern Russia right across to the Bering Sea.
The Northern Bumblebee is an important pollinator of the short-lived arctic flowers, visiting the blossoms of Arctic Poppies, Arctic Roses and Arctic Willows. It is one of the few pollinating insects that is sufficiently well insulated with a furry coat to brave arctic temperatures. And like all bumblebees, the Northern can vibrate its thoracic muscles to raise its body temperature to 86 degrees F. or higher. It can also sit in the center of an Arctic Poppy, and using the petals like a parabolic solar reflector, absorb more heat from the sun than if it sat on a leaf of the plant. Finally, B. polaris has apparently adapted to arctic conditions by developing the ability to maintain better control over the temperature in its abdomen, holding it several degrees warmer than in temperate zone bumblebees.
On October 12, 2007, Canada Post recognized this beneficial arctic pioneer by issuing a 5 cent stamp in its honor. The bee is shown busily foraging on a flower head of Red Clover. Could this be an error promulgated by the Canadian postal system? Does Red Clover extend into the high arctic?
Well most bumble bees certainly seem to love Red Clover. And this important agricultural crop plant, introduced into North America, is apparently found as far north as James Bay. But it probably does not extend into the high arctic. All is not lost, however, for the range of the Northern Bumblebee in Canada extends well south of James Bay in Ontario. So Bombus polaris could well indeed feed on Red Clover flowers, and probably does whenever it can find them.
Much thanks to Nativeplantgirl for finding and passing along these wonderful stamps.