15 Incredible Ways Animals Stay Warm When It's Chilly

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istock

Winter is coming, and while humans have the option of adding layers of clothing or cranking up the furnace, animals have to rely on their biology or resources to stay warm in the wild. Here are some of the ways our furry and scaly friends survive the cold. 

1. LEANING BACK

In addition to having a specialized circulatory system in their feet and flippers, emperor penguins often lean back onto their heels to get their toes off the ice. Their wedge-shaped tails provide stability, and there is no risk of losing heat because blood doesn’t flow through their tail feathers.

2. INCREASING BLOOD GLUCOSE LEVELS

Some reptiles and amphibians like the European common lizard have the ability to increase their glucose levels during the colder months so that lethal ice crystals won’t form and puncture their blood vessels. The process is reversed as temperatures rise.

3. RELAXING IN HOT SPRINGS

Most of the photos on the Internet of Japanese macaques show the pink-faced snow monkeys grooming one another in one of the country’s many natural spas. Known as onsens, the hot springs have become big tourist attractions, which has not deterred the monkeys from returning every winter.

4. MAKING ANTIFREEZE

Scientists have found that Alaskan wood frogs and other species take hibernation one step further: Their bodies freeze during the winter. Glucose in the blood prevents their cells from freezing and prevents dehydration, but all bodily processes (including heart and brain function) stop during this time. According to scientists, the frogs are essentially dead—until spring comes, temperatures rise, and the frogs spring to life again. 

5. BUILDING SNOW BUNKERS

Burrowing into compressed snow traps air and creates an insulated pocket, just like how igloos work. Lemmings and other small animals build tunnel systems to stay safe from the wind, cold, and predators. 

6. SHUTTING DOWN THEIR LUNGS

Scientists previously thought that freshwater turtles slipped into comas during cold winters, but a 2013 study found that the reptiles still responded to stimuli. Short of going completely comatose, the turtles slow their metabolisms and self-anesthetize, shutting down organs until warmer days return. 

7. GROUP HUDDLE

What’s better than one body covered in layers of warm feathers? Try hundreds of them, standing flipper-to-flipper and moving in unison. Emperor penguins know that huddles are not just for football—they’re also a really good way to share the warmth. The wave of moving tuxedo-clad birds has been compared to a traffic jam, with the slightest movement by one penguin causing a ripple throughout the crowd. Research has also shown that the penguins are not crammed together, but instead stand barely touching so that no penguin’s feathers get compressed.

8. JUST KEEP FLYING

Some birds, like the Alpine swift, head for warmer climates in the winter. A study found that the swifts are able to stay in the air for six months at a time without touching the ground, subsisting on aerial plankton—a mix of small insects, bacteria, and spores found in the air—and forgoing sleep (scientists are divided as to whether the birds skip sleep completely, or catch some shut-eye during short periods spent gliding, rather than flapping). By the time the birds return to their starting location, they have six months to rest and refuel before they start their journey again. 

9. BUILDING FAT RESERVES

Some animals eat more in the summer months so that they can store fat for the winter. The fat-tailed dwarf lemur, as the name suggests, uses its tail as a fat bank, increasing its body weight by as much as 40 percent. 

10. DEEP SLEEP

Unlike other hibernating animals, North American black bears have the special ability to lower their metabolism without a dramatic drop in body temperature. What’s better than a toasty nap on a cold winter day? 

11. STEALING HEAT FROM OTHERS

In a process called kleptothermy, reptiles like the tuatara steal the body heat of animals from completely different species. One study observed that the animals entered the nests of seabirds at night while the owners were still home so that they could benefit from the birds’ higher body temperature. 

12. RELY ON HUMANS

Cats caught out in the cold often seek shelter under cars because the engines are an enticing source of heat (so always check before driving off). Smaller critters also enter homes in the winter to mooch off of the free warmth inside the walls. 

13. GROWING INSULATION

It’s common for animals, from domestic dogs to wild foxes, to grow thicker fur as added insulation. It’s easier to grow than it is to get rid of—creatures like the elk of Colorado have to scratch or lick off their winter coats once the weather warms up. 

14. GOING TORPID

Unlike hibernation, which is a long-term state, the torpor state happens in waves and can be frequent. Some species of birds enter torpor every day in the cold months to stay alive by lowering their heart and metabolic rates.

15. SHIVERING

Some animals shiver to stay warm just like we do. And it’s not only the warm-blooded ones—bees also shiver by vibrating their muscles and keeping their wings still.

Chimpanzees Bond by Watching Movies Together, Too

Windzepher/iStock via Getty Images
Windzepher/iStock via Getty Images

Scientists at the Wolfgang Kohler Primate Research Center in Germany recently discovered that, like humans, chimpanzees bond when they watch movies together, the BBC reports.

In the study, published in Proceedings of the Royal Society B, researchers stationed pairs of chimpanzees in front of screens that showed a video of a family of chimps playing with a young chimp. They found that afterward, the chimps would spend more time grooming and interacting with each other—or simply being in the same part of the room—than they would without having watched the video.

They gave the chimps fruit juice to keep them calm and occupied while they viewed the video, and they chose a subject that chimps have previously proven to be most interested in: other chimps. They also used eye trackers to ensure the chimps were actually watching the video. If you’ve ever watched a movie with friends, you might notice similarities between the chimps’ experience and your own. Drinks (and snacks) also keep us calm and occupied while we watch, and we like to watch movies about other humans. Since this study only showed that chimps bond over programs about their own species, we don’t know if it would work the same way if they watched something completely unrelated to them, like humans do—say, The Lion King.

Bonding through shared experiences was thought to be one of the traits that make us uniquely human, and some researchers have argued that other species don’t have the psychological mechanisms to realize that they’re even sharing an experience with another. This study suggests that social activities for apes don’t just serve utilitarian purposes like traveling together for safety, and that they’re capable of a more human-like social closeness.

The part that is uniquely human about this study is the fact that they were studying the effect of a screen, as opposed to something less man-made. The chimps in question have participated in other studies, so they may be more accustomed to that technology than wild apes. But the study demonstrates that we’re not the only species capable of social interaction for the sake of social interaction.

[h/t BBC]

10 Facts You Should Know About Mosquitoes

tskstock/iStock via Getty Images
tskstock/iStock via Getty Images

Between the itching and the welts and the fears of mosquito-borne viruses, it's easy to forget that mosquitoes are a wonder of evolution, and that maybe they don't get a fair shake from us. Of more than 3000 known species, only 80 actually bite people, and at least one eats other mosquitoes for us. They grow from egg to adult in just five days, begin mating within minutes of hatching, and possess, by way of their stinging mouthparts, some of the coolest appendages in the animal kingdom.

1. Mosquitoes are excellent flyers in bad weather.

The average raindrop is 50 times heavier than the average mosquito, yet they buzz around in the rain with no problems. If a Boeing 747 got whacked with a similarly scaled-up raindrop, there would be 2375 tons of water coming down on it, and things probably wouldn’t turn out as well as they do for the mosquito. How do the insects do it?

A common urban legend said that the bugs were nimble enough to dodge the drops. A few years ago, a team of engineers from the Georgia Institute of Technology watched real mosquitoes and Styrofoam dummy mosquitoes with a high-speed camera during a rainy flight to see if that’s what was really happening. They found that the bugs don’t fly fast enough to dodge the drops, but their slowness is what keeps them from getting knocked out of the sky. A mosquito’s low mass even at slow speed doesn’t provide enough of a target for a raindrop to splash on collision. Instead, the drop just deforms, and doesn’t transfer enough momentum to the mosquito to disrupt its flight.

2. Texas is the mosquito capital of America.

Of the 3000 species of mosquitoes around the world, at least 150 are found in the United States, and 85 of those call Texas home. When people say everything's bigger in Texas, you can also include the biodiversity of the state's biting, disease-carrying insects.

3. Some mosquitoes are truly dangerous to humans ...

The female mosquito, which is the one that stings and sucks blood, is an incredible transmitter of disease and, because of that, the deadliest animal in the world. Each year, the malaria parasites they transmit kill 2 million to 3 million people and infect another 200 million or more. They also spread pathogens that cause yellow fever, dengue fever, Rift Valley fever, Chikungunya and West Nile disease.

4. ... and some mosquitoes are harmless.

Not every species of mosquito sucks blood from people, and among those that do, not every one transmits disease. The blood suckers don’t even need to bite you for every meal. Males live entirely on nectar and other plant fluids, and the females’ diet is primarily plant-based, too. Most of the time, they only go after people when they’re ready to reproduce, because blood contains lipids, proteins, and other nutrients needed for the production of eggs.

5. MosquitoEs actually help the environment.

When you’re rubbing calamine lotion all over yourself, mosquitoes might not seem to serve any purpose but to annoy you, but many species play important ecological roles. The mosquitoes Aedes impiger and Aedes nigripes, which gather in thick clouds in Arctic Russia and Canada, are an important food source for migrating birds. Farther south, birds, insects, spiders, salamanders, lizards, frogs, and fish also eat different mosquito species regularly. Plants need them, too, and some, like the blunt-leaved orchid and endangered monkeyface orchid, rely on mosquitoes as their primary pollinator.

Some mosquito species are also excellent at mosquito control. Species of the genus Toxorhynchites feed on the larvae and immature stages of other mosquitoes and will sometimes even cannibalize members of their own species.

6. Mosquitoes are amazing hunters (as if we needed to tell you that).

Mosquitoes are adept at picking up on the chemicals given off by their human hosts. They can detect the carbon dioxide in our breath, the 1-octen-3-ol in our breath and sweat, and other organic substances we produce with the 70-plus types of odor and chemical receptors in their antennae. These receptors can pick up traces of chemicals from hundreds of feet away, and once the mosquito closes in, it tracks its meal chemically and also visually—and they’re fond of people wearing dark colors.

7. Mosquitoes can be picky.

If it seems like you’re always covered head to toe by bites while people who were sitting right next to you only have one or two, it’s not just paranoia; the skeeters actually are out to get you. Some people happen to give off more of the odors and compounds that mosquitoes find simply irresistible, while others emit less of those and more of the compounds that make them unattractive to mosquitoes—either by acting as repellents or by masking the compounds that mosquitoes would find attractive.

8. A female mosquito's mouth is primed for sucking blood.

A mosquito doesn’t simply sink its proboscis into your skin and start sucking. What you see sticking out of a mosquito’s face is the labium, which sheaths the mouthparts that really do all the work. The labium bends back when a mosquito bites, allowing these other parts to pass through its tip and do their thing. The sharp, pointed mandibles and maxillae, which both come in pairs, are used to pierce the skin, and the hollow hypopharynx and the labrum are used to deliver saliva and draw blood, respectively.

9. Mosquito saliva prevents blood clotting.

The saliva that gets pumped out from the hypopharynx during a bite is necessary to get around our blood’s tendency to clot. It contains a grab bag of chemicals that suppress vascular constriction, blood clotting and platelet aggregation, keeping our blood from clogging up the mosquitoes' labrum and ruining their meal.

10. Mosquitoes can explode.

Blood pressure makes a mosquito's meal easier by helping to fill its stomach faster, but urban legend says it can also lead to their doom. Story goes, you can flex a muscle close to the bite site or stretch your skin taut so the mosquito can’t pull out its proboscis and your blood pressure will fill the bug until it bursts. The consensus among entomologists seems to be that this is bunk, but there is a more complicated way of blowing the bugs up. To make a blood bomb, you’ve got to sever the mosquito’s ventral nerve cord, which transmits information about satiety. When it's cut, the cord can’t tell the mosquito’s brain that its stomach is full, so it’ll keep feeding until it reaches critical mass. At least one researcher found that mosquitoes clueless about how full they were would keep sucking even after their guts had exploded, sending showers of blood spilling out of their blown-out back end.

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