Tag Archives: night

Sleeping bear.

Wildlife is shifting activity to nighttime because they don’t want to run into humans

Humans are bugging wild animals — so the critters are staying hidden during the day.

Sleeping bear.

Image via Pixabay.

Animals are finding that the best way to deal with those pesky humans isn’t to go live someplace else, but to start living during the night. The findings, published by researchers from the University of California–Berkeley and Boise State University, show that previously-diurnal animals are shifting activity during night hours to avoid humans.

Under the cover of darkness

The team analyzed 76 studies involving 62 species of mammals on six continents, from opossums to elephants. These studies looked at how individual species changed their behavioral patterns in response to human activity such as hunting, farming, or development. Each study used some sort of technique to follow animals, from GPS trackers to motion-activated cameras.

The team then compared how much time those creatures spent actively at night under different types of human disturbance. One common feature all the surveyed animals shared was that they became far more active at night after humans arrived, the team reports. On average, they found that human presence triggered an increase of about 20 percent in nighttime activity, even in animals that aren’t normally night owls. Strikingly, the animals even delegated critical tasks such as hunting and foraging for nighttime activity. The team further reports that mammals which used to split activity roughly even between the day and night also shift more strongly towards darker hours — on average, these species increased nighttime activity to 68%.

It also became apparent that human activity doesn’t need to directly impact these species to determine a change in behavior. The team notes that all species responded similarly to human encroachment in their habitats. A deer, for example, will shift activity towards nighttime regardless if the humans it sees are hunters or hikers.

“It suggests that animals might be playing it safe around people,” Kaitlyn Gaynor, an ecologist at the University of California, Berkeley, who led the study, told PBS. “We may think that we leave no trace when we’re just hiking in the woods, but our mere presence can have lasting consequences.”

This shift in activity does help humans and animals coexist with less friction, the team notes. The findings might also help us design better conservation strategies that take into account species’ patterns of activity.

However, there’s also cause for concern. A nocturnal lifestyle can impact an animal’s ability to get food or mate, impacting the short- and long-term stability of whole species. This, ironically, also defeats the purpose of shifting activity in the first place. If animals are becoming more active at night to avoid us, but that only makes life harder for them, have they really escaped the impact of human activity?

The paper “The influence of human disturbance on wildlife nocturnality” has been published in the journal Science.


Just two days of night-shift alter the activity of more than 100 blood proteins

Sleeping during the day and staying up all night will impact the concentration and activity of over 100 proteins in the blood — even if you only do it for short while.


Image credits picsessionarts / Flickr.

Staying awake and eating during the night throws a wrench in the activity of blood-borne proteins, according to new research from the University of Colorado Boulder. The proteins identified by the team impact processes involved in a wide array of metabolic functions, from blood sugar levels to immune function. The study is the first to examine how protein levels in human blood, also known as the plasma proteome, vary over a 24-hour period and how altered sleep and meal timing affects them.

Protein shift

“This tells us that when we experience things like jet lag or a couple of nights of shift work, we very rapidly alter our normal physiology in a way that if sustained can be detrimental to our health,” said senior author Kenneth Wright, director of the Sleep and Chronobiology Laboratory and Professor in the Department of Integrative Physiology.

The team enlisted the help of six healthy male subjects in their 20s for the study. The participants were asked to spend six days at the university’s clinical translational research center. While here, their meals, sleeping hours, active periods and the hours they were exposed to light were tightly controlled and recorded.

On the first two days, the men were kept on a normal schedule: active hours and light exposure during the day, sleeping hours at night. They were then gradually transitioned to a night-shift work pattern —  they could get an eight-hour sleep if they wanted, but only during the day, and stayed up and ate at night. The team collected blood samples every four hours, which they analyzed for the concentrations and time-of-day-patterns of 1,129 proteins.

They report that 129 of these proteins’ patterns were thrown off by the simulated night shift. The effect was already noticeable by the second day of night-shift waking patterns, Depner adds.

One of the affected proteins was glucagon — which tells the liver to inject sugar into the bloodstream. Glucagon levels in the blood peaked during waking hours, the team found, meaning they shifted to night-hours as the participants started staying awake at night. But it also peaked in higher concentrations, the team adds. They think that this effect could, in the long-term, form the root cause of the higher diabetes rates seen in night-shift workers.

Night-shift wakefulness patterns also decreased blood levels of fibroblast growth factor 19. Previous research with animal models has shown this protein to boost calorie-burning and energy expenditure, the team adds. The participants in this study burned 10% fewer calories per minute when their schedule was misaligned.

Overall, thirty proteins showed a clear 24-hour-cycle, most showing a peak between 2 p.m. and 9 p.m.

“The takeaway: When it comes to diagnostic blood tests—which are relied upon more often in the age of precision medicine—timing matters,” said senior author Kenneth Wright.

The authors note that all the participants were kept in dim light conditions, to eliminate the effect of light-exposure (which can also strongly affect the circadian system) on the results. Even without the glow of electronics at night, changes in protein patterns were rapid and widespread.

“This shows that the problem is not just light at night,” Wright said. “When people eat at the wrong time or are awake at the wrong time that can have consequences too.”

The findings could lead to new treatment options for night shift workers, who are at a higher risk for diabetes and cancer. It could also enable doctors to precisely time administration of drugs, vaccines and diagnostic tests around the circadian clock.

The paper “Mistimed food intake and sleep alters 24-hour time-of-day patterns of the human plasma proteome” has been published in the journal PNAS.

Can’t get any rest when sleeping in a new place? It’s just your brain keeping you safe

A new study offers insight into why you might have a hard time sleeping on the first night in a new place: half of your brain stays awake to watch out for potential dangers.

Image credits Jacob Stewart / flickr

If you’re anything like me you know that feeling you get when sleeping in a new place — it’s not necessarily (but often) a restless night, and even if you do get some sleep it just feels somehow off. If you keep in mind that our brains are still wired to keep us alive in the wild, there’s a pretty straightforward explanation, a new study finds.

Yuka Sasaki of Brown University and her team recruited 35 people to spend several nights in a sleep lab, while they monitored their brain activity with advanced imaging techniques. The results consistently show that on the first night in the lab, subjects’ left hemispheres remained more active during deep sleep (or “slow-wave sleep”) than the right ones. This effect is similar to that seen in marine mammals, that only shut down one half of their brain at a time during sleep, but much less pronounced.

“We know that marine animals and some birds show unihemispheric sleep, one awake and the other asleep,” says Yuka Sasaki of Brown University. “[The findings suggests that] our brains may have a miniature system of what whales and dolphins have.”

The so-called first night effect seems to be caused by the difference in brain activity between the two hemispheres — the more pronounced this difference, the harder it was for participants to fall asleep. The hemisphere with increased activity also showed greater response to sounds — the team found that playing beeping noises in the right ear (corresponding to the left hemisphere) woke participants up more easily than when played in the left ear.

Those asymmetries observed during the first night of sleep weren’t evident in subsequent sleep sessions. All this suggests that our brains delegate the left hemisphere to retain part of its activity when we’re sleeping in a new environment. This way it can serve as a “night watch” that wakes the sleeper up if there’s danger, the researchers said.

But there are things you can do to improve your sleep: just lull your brain into a sense of safety. Bring your pillow along or find a accommodation similar to your usual sleeping spot.

“Human’s brains are very flexible,” Sasaki says. “Thus, people who often are in new places may not necessarily have poor sleep on a regular basis.”

The researchers are planning to test if this first night effect can be reduced or eliminated by lowering brain activity throung transcranial magnetic stimulation.

The full paper, titled “Night Watch in One Brain Hemisphere during Sleep Associated with the First-Night Effect in Humans” has been published online in the journal Current Biology and can be read here.

An hour nap restores your brain’s energy

sleep-learningA recent study published by Berkeley UC concluded that an hour nap boosts the brain’s learning capacity and restores power, just like an email box. When it’s full, it needs a cleaning session – which is just what the nap does.

So of course, what every student had to learn the hard way, when you study and do an all nighter, your brain’s efficiency goes down a lot; according to the researchers, about 40%. This happens because some of the regions in the brain basically shut down to save energy, so you need sleep to work at full power.

The study went even further and concluded that the more you stay awake, the harder it will be for you to learn new things. From what I can understand, it’s actually better to remove an hour of night sleep and add it in the evening, if nothing else is possible. Learn more about napping.

Cities as seen from space, at night


Recently, the NASA observatory published some great images of some cities. For a man looking at those cities at night, man’s work seems both impressive and insignificant. But the view would be fantastic: regular patterns of irrigated cropland, straight lines of roads and railways running across continents, reservoirs on river systems, and the cement rectangles of ports and seawalls along coastlines.But nothing would be as gorgeous as the cities. During the day, it’s not really spectacular: gray smudges is pretty much all you get. However at night… things change a bit. The lights pinpoint how humanity have changed the environment to make it adapt to his own needs.



If anything rocks about being an astronaut, it’s being able to see the earth at night: from 350-400 kilometers above the surface you get to see the magnificent display of lights and patterns.


But taking pictures in the dark is difficult at best, made even more difficult by the fact that the International Space Station moves more than 7 kilometers per second (15,659 miles per hour) relative to Earth’s surface. Still, hopefully you From a geographic perspective, cities at night tell different stories about a region. They took way more pictures than we’ve shown here. You can check them all out here.