The Lapland Longspur: Barrow's Very Punctual Summer Resident

The 24 hours of summertime sunlight in Barrow, Alaska is enough to throw any person's daily schedule into a tailspin. Trying to get a good night's sleep in broad daylight is tricky enough, and keeping track of whether it's day or night can be mind bending. But the Lapland Longspur (Calcarius lapponicus) doesn't seem bothered by the fact the sun doesn't set in Barrow during the summer. These tiny songbirds manage to keep their internal clock ticking perfectly.

Noah Ashley, a post doctorate fellow at the University of Alaska Anchorage, has spent the last two summer field seasons in Barrow trying to determine exactly how the Lapland Longspur manages to regulate its behaviors and which external environmental cues they use to reset their circadian rhythms.

Circadian rhythms play a key role in how humans and animals time their behaviors--helping to regulate important daily functions like sleeping and eating. Normally, these rhythms are synchronized everyday by the light-dark patterns of the day and night. During the long periods of daylight or darkness in the Arctic, caribou and other birds like the Rock Ptarmigan will completely abandon their circadian rhythms. But the Lapland Longspur does just the opposite.

"When they're in Alaska during the breeding season, these birds will actually exhibit a very distinct rhythm that other animals will abandon," Ashley explained. "They will be active throughout the entire day. And then around subjective 'midnight' they'll basically hunker down in the tundra and become quiescent until about 4:30 a.m. These birds are synchronizing their rhythms with some unknown environmental signal that other animals are not cueing in on."

The Lapland Longspur's very punctual behavior patterns piqued Ashley's curiosity. He speculated that subtle changes in light intensity or slight variations to the color of the sunlight as the day progressed might actually be regulating the birds' behavior. With funding from the National Science Foundation he put together a team and set out to unravel these little birds' timely mystery.

Read the rest of this article by Alicia Clark in "Field Notes: The Polar Fields Services Newsletter."