Evidence that birds sleep while flying

We already know that some birds can fly for weeks or even months at a time without landing, but this remarkable ability has raised a few questions about how, if at all, these creatures find the time to sleep. In the first study of its kind, scientists have monitored the brain activity of seabirds in flight and discovered that they regularly squeeze in some shut-eye while out searching for food, though how they perform on such little rest remains a little unclear.

If there was ever a bird well-suited to sleeping on the job, it might be the frigatebird, a large seabird that scans the ocean surface for flying fish and squid. Recent research has shown that these elite gliders can stay aloft for months by hitching rides on clouds and are among the longest-flying creatures in the seabird world. But even frigatebirds need their sleep, so scientists have been perplexed as to how they maintain performance without regularly coming down for rest…

To find some conclusive answers, an international team of scientists hooked up frigatebirds nesting on the Galápagos Island to a device to monitor electroencephalographic (EEG) activity and head movement during flight. This recorder was carted along for 10-day flights across 3,000 km (1,864 mi) with a GPS module on the bird’s back to monitor their position and altitude.

The data showed that during the day, the birds remained awake while searching for food, so business as usual. But when the sun went down and the birds soared, the awake EEG pattern changed to a slow-wave sleep pattern, sometimes for minutes at a time. This SWS often occurred in one half of the brain, but interestingly, sometimes in both hemispheres at the same time, suggesting that unihemispheric sleep isn’t critical to maintaining aerodynamic control.

Compared to how frigatebirds sleep on land, however, the SWS sleep mode was more frequent. By tracking the head movements of the birds, the researchers found that as they circle on rising air currents while sleeping in this way, it allowed them to keep one eye open in the direction they were turning.

The big surprise was that the frigatebirds were only sleeping for 42 minutes per day — compared to the usual 12 hours a day on land. Working out comparisons with what we know about sleep and sleep deprivation in other species – like us – will be part of where these studies will be going next.

“We need sleep. It cleans up the brain”


A good night’s rest may literally clear the mind. Using mice, researchers showed for the first time that the space between brain cells may increase during sleep, allowing the brain to flush out toxins that build up during waking hours. These results suggest a new role for sleep in health and disease…

“Sleep changes the cellular structure of the brain. It appears to be a completely different state,” said Maiken Nedergaard…a leader of the study.

For centuries, scientists and philosophers have wondered why people sleep and how it affects the brain. Only recently have scientists shown that sleep is important for storing memories. In this study, Dr. Nedergaard and her colleagues unexpectedly found that sleep may be also be the period when the brain cleanses itself of toxic molecules.

Their results, published in Science, show that during sleep a “plumbing” system, called the glymphatic system, may open, letting fluid flow rapidly through brain. Dr. Nedergaard’s lab recently discovered the glymphatic system helps control whether cerebrospinal fluid (CSF), a clear liquid surrounding the brain and spinal cord, flows through the brain.

“It’s as if Dr. Nedergaard and her colleagues have uncovered a network of hidden caves and these exciting results highlight the potential importance of the network in normal brain function,” said Roderick Corriveau, Ph.D….

The results may also highlight the importance of sleep…“We need sleep. It cleans up the brain,” said Dr. Nedergaard.

RTFA for details of testing and discovery. Sleep studies, the rate of expansion of specialized testing and treatment of ailments like sleep apnea surprise and please me. When I did the testing – nine years ago – that resulted in my CPAP sleeping gear I had to drive fifty miles for the overnight hookup. Now, I can send folks who ask me about treatment to a few local choices.

As treatment and experience accumulate a body of data, more and better treatment continues to develop. Science and healthcare have another avenue opened to improve life.

A caffeinated secret to long life?

People who live on the Greek island of Ikaria are known to have remarkably high life expectancies, and researchers have been studying them carefully to learn why. Now a new report suggests that one reason may be the coffee they drink.

“This boiled coffee seems to generate antioxidant substances,” said Dr. Gerasimos Siasos, a professor at the University of Athens Medical School and an author of the study, which appears in the journal Vascular Medicine.

He and his colleagues found that older islanders who drank the boiled coffee had better functioning endotheliums — the layer of cells that line blood vessels.

“When there is dysfunction here, the arteries become more stiff, and we have heart attacks and arterial occlusions,” said Dr. Siasos, who did the research with his colleague Dr. Christodoulos Stefanadis.

Of course, coffee is only one factor. “It has to do with their way of living,” Dr. Siasos said. “People sleep over eight hours a night, there is increased socializing, and they have much less stress than people in Athens.”

The islanders also eat a Mediterranean diet that includes many fruits, vegetables, olive oil and fish. Most also nap every day and walk and garden regularly, Dr. Siasos said.

The researchers will journey to Ikaria this summer to study how the island’s water, minerals and air quality might also be contributing to longevity.

If they pay close attention to the research they may just decide to stay there instead of returning to Athens. Between sleeping better, eating healthier, living a less stressful life – plus the boiled coffee – I can think of a whole boatload of reasons NOT to leave.

Earliest human beds in South African archaeological site

A team working in South Africa claims to have found the earliest known sleeping mats, made of plant material and dated up to 77,000 years ago — 50,000 years earlier than previous evidence for human bedding. These early mattresses apparently were even specially prepared to be resistant to mosquitoes and other insects.

Early members of our species, Homo sapiens, were nomads who made their living by hunting and gathering. Yet they often created temporary base camps where they cooked food and spent the night. One of the best studied of these camps is Sibudu Cave, a rock shelter in a cliff face above South Africa’s Tongati River, about 40 kilometers north of Durban. Sibudu was first occupied by modern humans at least 77,000 years ago and continued to serve as a favored gathering place over the following 40,000 years. Since 1998, a team led by Lyn Wadley, an archaeologist at the University of the Witwatersrand, Johannesburg, has been excavating at Sibudu, uncovering evidence for complex behaviors, including the earliest known use of bows and arrows.

Over the past several years, the team has found that many of the archaeological layers featured large, 1-centimeter thick swaths of plant remains, including the remnants of both stems and leaves. Most of them cover at least three square meters. The team suspected that these swaths were the remains of bedding, but the earliest previous evidence for sleeping mats is only between 20,000 and 30,000 years old, at sites in Spain, South Africa, and Israel, where similar but more fragmentary arrangements of plant remains have been found…

The team found that the swaths, which dated from 77,000 to 58,000 years ago, were made from sedges, rushes, and grasses, plants that grow down by the Tongati River but are not found in the dry rock shelter. Thus the people at Sibudu must have gathered them deliberately and brought them to the cave. Under the microscope, blocks of the plant material showed signs of compression and repeated trampling. In the earliest layer, 77,000 years old, the team found the leaves of Cryptocarya woodii, also known as Cape laurel, or the “bastard camphor tree,” an aromatic plant whose leaves are used in traditional medicines even today. The leaves contain several chemical compounds that can kill insects, and the team suggests that early humans chose them to protect against malaria-carrying mosquitoes and other pests…

Among the plant remains, Wadley’s team also found tiny fragments of chipped stone and crushed, burnt bone, which the researchers interpret as evidence that these were not only sleeping mats but also work surfaces where tools were fashioned and food was prepared. Thus while early modern humans were skilled at organizing their living spaces, some parts of the cave served double duty, Wadley says. “There were no rules for separate eating, working, or sleeping places,” she says. “Breakfast in bed may have been an almost daily occurrence.”

AAAS articles are almost always informative, useful, educational. Sometimes the effort to be entertaining can be pretty corny. 🙂

Among the various substances and structures they examined at microscopic level I wonder what remains of insects associated with humans may have been found? Like fossilized Cimex lectularius?

Study debunked that men think about sex every 7 seconds!

Men may think about sex more often than women do, but a new study suggests that men also think about other biological needs, such as eating and sleep, more frequently than women do, as well.

And the research discredits the persistent stereotype that men think about sex every seven seconds, which would amount to more than 8,000 thoughts about sex in 16 waking hours. In the study, the median number of young men’s thought about sex stood at almost 19 times per day. Young women in the study reported a median of nearly 10 thoughts about sex per day.

As a group, the men also thought about food almost 18 times per day and sleep almost 11 times per day, compared to women’s median number of thoughts about eating and sleep, at nearly 15 times and about 8 1/2 times, respectively…

“If you had to know one thing about a person to best predict how often they would be thinking about sex, you’d be better off knowing their emotional orientation toward sexuality, as opposed to knowing whether they were male or female,” said Terri Fisher, professor of psychology at Ohio State University’s Mansfield campus and lead author of the study. “Frequency of thinking about sex is related to variables beyond one’s biological sex…”

Before the thought-tracking began, the participants completed a number of questionnaires. These included a sexual opinion survey to measure a positive or negative emotional orientation toward sexuality (erotophilia vs. erotophobia); a sociosexual orientation inventory measuring attitudes about sex and tracking sexual behavior and levels of desire; a social desirability scale to measure respondents’ tendency to try to appear socially acceptable; and an eating habits questionnaire and sleepiness scale. They also were asked to estimate how many times in an average day that they thought about sleeping, eating and sex…

And when all of those thoughts were taken into account in the statistical analysis, the difference between men and women in their average number of daily thoughts about sex wasn’t considered any larger than the gender differences between thoughts about sleep or thoughts about food.

I joke that I don’t differentiate much between food and sex. Folks always chuckle – for the wrong reason. They think I mean food is as important as sex when what I mean is that sex is as important as food. 🙂

Wake up tired in the morning? Maybe you have Sexsomnia?

Some people sleepwalk; others talk in their sleep. Now a study finds that 1 in 12 patients with sleep disorders reported having had sex while they were asleep.

Researchers reviewed the medical charts of 832 consecutive patients seeking help at a Toronto sleep center and found that 63 patients, or 7.6 percent, reported either having had sex or engaging in other sexual activity, like masturbating, while asleep.

The phenomenon, called sexsomnia, is a form of parasomnia, a disorder in which people who are asleep but in a state of semi-arousal engage in behaviors they are not conscious of. Sexsomnia is defined by the International Classification of Sleep Disorders and may take place during a sleepwalking episode…

The author, Sharon A. Chung, a scientist at the Sleep Research Laboratory at Toronto Western Hospital, says the behavior becomes a problem when it disrupts the normal sleep cycle.

At night you’re supposed to be sleeping,” she said in an interview. “Anything that stops you from sleeping at night is bad — not because of the behavior, because it stops you from sleeping.”

Looking back on my somewhat checkered past, I can say – with a smile of relief – that all the sex I ever experienced when I was supposed to be sleeping was while I was awake to enjoy it.