Winter has officially arrived in the Northern Hemisphere. With today’s winter solstice, the days will start to get a little bit longer, but the cold will stick around. We humans typically handle the dipping temperatures by staying inside, sleeping more, and dressing in layers. But what about other members of the animal kingdom? Here are some unique ways that animals survive winter’s deep freeze.  Brumation nation To fend off winter’s chill, some reptiles and all amphibians brumate. Brumation is basically a less intense form of hibernation. Bears and other mammals who hibernate spend a lot of the time sleeping. Instead, brumating amphibians and reptiles go through a period of dormancy with small bursts of activity.  “During the winter, brumation is like taking a long nap, getting up when it gets a little warmer, going to the bathroom, drinking some water, and then going back to sleep,” Karen McDonald, the STEM program coordinator at the Smithsonian Environmental Research Center in Maryland tells Popular Science. “Hibernation is sleeping all winter and relying on your fat stores.” Reptiles and amphibians need to wake up in order to drink water so that they don’t get dehydrated. They will typically get up for that refreshing sip on more mild winter days. If they’re lucky, they’ll get some extra sun in the process.  Wood frog in Minnesota. Unlike most other frogs that spend their winters underwater, the wood frog stays on land and freezes solid. Image: Jasper Shide / Public Domain. Frozen frogs When cold fronts swoop down to Florida, frozen iguanas will inevitably fall out of trees. But for the wood frogs that live across New England, the Mid-Atlantic, and Midwest that cold is much more frequent. However, their solution is not brumating. Instead, they freeze solid. For months, wood frogs will burrow underneath leaf litter on forest floors with no breathing, heartbeat, or brain activity. Once the weather begins to warm, they will spring back to life. According to the National Park Service, this strategy allows wood frogs to become active very early in spring. The land thaws and warms more quickly than the ice-covered lakes where other frogs burrow in the mud. This means that the newly active wood frogs can mate and lay eggs in small ponds earlier than other frogs. Take care of those feathers Not all bird species survive the winter by flying south to warmer climates. Some, like cardinals, chickadees, and blue jays stay put. In order to survive the cold, they have to take very good care of their feathers. Some species will grow all new feathers for the winter. Other birds will fluff up their feathers to help trap pockets of air around their bodies to stay warm. Preening also helps some birds waterproof their feathers, by spreading oil from a gland near their tails to the rest of their body. Birds will also find good places to hunker down or huddle up with other birds of the same species. Winterberries and some other plants will also still produce fruit that can help keep them fed until spring. A well-stocked bird feeder can also help, just be sure to keep it clean. A northern cardinal visits a feeder at the Smithsonian Environmental Research Center. Image: Haley Jackson / Smithsonian Environmental Research Center. Blue (crab) Christmas The blue crabs that call the Chesapeake Bay home spend their winters in deeper parts of the bay. There, they burrow into the mud underwater and enter a dormant state. “This is not traditionally considered hibernation because unlike some mammals, crabs don’t undergo physiological changes that reduce their body temperature,” Smithsonian Environmental Research Center senior researcher Matt Ogburn tells Popular Science. “Nonetheless, they are still largely inactive and their metabolism slows down.” The blue crabs will stay that way until water temperatures reach approximately 50 degrees Fahrenheit. Blue crabs, a keystone species in the Chesapeake Bay, spend their winters buried under the mud in the deepest part of the Bay, in a dormant state. Image: Smithsonian Environmental Research Center. ‘As solitary as an oyster’ We’re not saying that oysters are lonely misers like Ebenezer Scrooge. These filter-feeders are actually very good for the planet. Oyster beds are important storm barriers and the bivalves help keep the water clean. In a single day, an oyster can filter up to 50 gallons of water. They get most of their food by filtering water through their bodies and grabbing nutrients like algae and plankton. However, those food sources dwindle up come winter.  A restored oyster reef in a sanctuary in Harris Creek, part of the Choptank River in Maryland. Oysters close their shells and live off their glycogen stores from the summer to make it through the winter. Image: Smithsonian Environmental Research Center Fisheries Conservation Lab. “Oysters feed frantically in summer, when there’s lots of algae around to filter out of the water, “ says Ogburn. “This helps them store up glycogen that they burn to survive the winter.” In winter, they will go dormant and survive on those stores of sugar, similar to what reptiles and amphibians rely on during brumation.  Yes, turtles do breathe through their butt Turtles spend the winter underwater—where they breathe out of their butts. While it may seem a bit unusual to us mammals, breathing through their butt is an important survival strategy.  “It allows turtles like snapping turtles and painted turtles to remain frozen under the ice and still breathe under water,” says McDonald. This process is called cloacal respiration, where they exchange gasses through the tissues lining their cloaca—the end of their digestive tract. This allows them to stay submerged underwater for longer periods of time. The post Butt breathing and 5 other ways animals stay warm in winter appeared first on Popular Science. ...read more read less