Sparrows' Pecking Out of Order

Though the stifling heat may indicate otherwise, we're closing in on autumn. The change in seasons means birds everywhere are getting ready for a change of scenery.

In particular, the white-crowned sparrow (Zonotrichia leucophrys) species is on the verge of its yearly migration.

The next time you spy the small black, white and grey birds during their spring or fall voyages, however, you may want to pay attention to how they're behaving.

Scientists say the birds are getting a bit confused, and the researchers have no idea why.

A team from the University of Wisconsin in Madison studied the effects of migratory versus non-migratory periods on a group of sparrows in a laboratory setting, controlling the amount of light the birds were exposed to in order to mimic the four seasons.

The researchers then gave the birds a task designed to reveal how well the animals could control their own behavior: pecking for food.

If the birds pecked a button, they would not receive their food reward. In other words, how well the birds learned not to peck hinted at their ability to control their behavior.

The researchers found that during the migratory seasons of spring and fall, the sparrows pecked much more recklessly and with more abandon than during summer and winter.

The animals were also getting about 60 percent less sleep during migration stages.

Lack of sleep isn't necessarily what's causing the birds to be what the researchers called more "impulsive."

“In the wild, despite marked reductions in apparent opportunity to sleep, birds continue to successfully engage in prolonged flight, complex navigation and predator evasion during migration," Ruth Benca, a study author, said in a press release.

"In contrast, in this study we demonstrate that, relative to birds in the non-migratory state, they struggle to learn when not to peck," she said.

Basically this means the birds are hyperactive in spring and autumn -- at least in a lab setting. It could partially be related to changing light conditions, but the researchers say they're essentially stumped.

The research appears in the journal BMC Genetics.