Whirling flocks of Snow Buntings have been observed more frequently lately, perhaps because male buntings have begun their migration back to their nesting grounds on the tundra. They are the first migrants to arrive in the Arctic in the spring (in early April), when it can be -20°F. Females arrive four to six weeks later, when days are warming and snow is beginning to melt. It is thought that the males’ early return is related to the fact that, unlike most Arctic songbirds, buntings nest in rock cavities, for which there is great competition. Deep inside narrow cracks, nesting buntings can largely avoid nest predation, but their eggs are susceptible to freezing and require longer incubation than eggs laid in the open. As a result, females remain on the nest throughout much of the incubation period and are fed by the males. This arrangement shortens incubation time and provides the eggs with constant protection from freezing temperatures. (Thanks to Liz and Clemens Steinrisser for photo op.)
Naturally Curious is supported by donations. If you choose to contribute, you may go to http://www.naturallycuriouswithmaryholland.wordpress.com and click on the yellow “donate” button.