BIRD RESEARCH AT SOUTHERN MISS
COULD SHED LIGHT ON HUMAN SLEEP DISORDERS
By Christopher Mapp

HATTIESBURG - Anyone who has every watched a furry feline relaxing by a fireplace knows the restorative powers of a catnap. But a "birdnap?"

By studying sleep loss and its effect on migratory birds, scientists at The University of Southern Mississippi are hoping to answer some questions about how these weary travelers cope without rest. In turn, the findings could prove useful for the millions of Americans who suffer from sleep disorders and sleep-deprivation.

Most birds are active during the day but migrate at night. Dr. Frank Moore, chair of the biology department at Southern Miss, says birds may make up for lost sleep at night by taking short naps - even perhaps while on long, migratory flights. This phenomenon - called "unihemispheric sleep" - occurs when one half of the bird's brain sleeps while the other remains active.

"Because birds are naturally sleep-deprived by the nature of their migratory habits, they may provide some insight in how animals, including humans, compensate for sleep loss," said Moore, whose research was funded by a grant from the National Science Foundation and was recently featured on National Geographic Magazine's Web site.

"Birds that lose sleep or don't compensate for losing it may suffer in their ability to find food or avoid predators," Moore added. "It's not unlike how our performance suffers when we go without sleep for long periods."

Along with Verner Bingam, a behavioral neuroscientist at Bowling Green, Moore is concentrating on one species of bird, called Swainson's thrush. Working with the species both in the lab and in the field, the researchers are able study the birds' behavior and electronically measure patterns of brain activity.

What Moore and his colleagues ultimately discover could shed light on human sleep as well, according to Dr. John Harsh, director of the Southern Miss Psychology Department's Sleep Laboratory.

"We all know from our personal experiences that loss of sleep results in sleepiness and a reduced ability to be productive and stay out of harm's way when we are awake," Harsh said. "Saying that we sleep to avoid sleepiness is, however, no more meaningful than saying we eat to avoid hunger."

Harsh said scientists still do not know the function of sleep and any new findings are of great interest. "That's why Dr. Moore's research is so important," Harsh added.

Like most bird species, Swainson's Thrush are active during the day and sleep at night, except during migration. Since these nighttime flights disrupt their normal sleeping patterns, the birds must make up for it somewhere, and Moore's research aims to uncover how.

"Migratory birds might devote more time to sleep during the day, and brief periods of sleep have been observed during the late afternoon just prior to the onset of nightly migratory restlessness," Moore said.

Sleeping more during the day could come at a cost, Moore said, because that is when birds forage for food. This can have serious consequences for a bird's health if, stressed from a long migratory flight, the bird puts its sleep needs before its caloric needs.

One way Moore suggests birds mitigate the conflict between sleep and wakefulness is by engaging in unihemispheric sleep, which is known to exist in some marine mammals.

This is where the similarities between humans and birds diverge. Harsh said, "There is a shared need for sleep, and sleep and wake states generally appear to be regulated by similar mechanisms."

However, the sleep of migrating birds is "dramatically changed" and in ways that we do not understand, Harsh said.

"Research that leads to understanding these changes is likely to bring us closer to an appreciation of the function of sleep and to a greater ability to treat the many disorders of sleep."

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