Winter weight for the winter wait

Hi, Ranger David here. Welcome to Shenandoah National Park. Guess what? Winter is here. It’s gotten cold; the days are gotten shorter; the leaves have fallen off the deciduous trees; the flowers are all gone, because that’s all indicators–to not only us, but to the wildlife–that it’s time to do something to get ready for the harsh, brutal winters that happen up here in the Blue Ridge Mountains. Now, I just called the winters up here brutal. What do you think it is that makes these winters so brutal up here? Well, let’s explore. First of all, the temperatures on average, temperatures during the winter here at Shenandoah National Park are 35 degrees-or so-cooler in the winter than they are in the summer. That means if the average daytime temperature in the middle of the summer is 75 degrees, in the wintertime that’s going to drop to 40 degrees for the high, and imagine a 55 degree low temperature at night dropping down to 20 degrees at night.

01:16 - So, that temperature change makes a big difference. Another thing that makes the winters harsh up here is 37 inches of snow on average here in Shenandoah National Park. So, we get a lot of snow here up in the mountains. Some years heavier, some years not so heavy, but that makes a big difference, and when you’ve got snow on the ground and on the roads in the park, like it gets to be, and long periods of cold that turns into a lot of ice. So, we get a lot of ice up here on the mountain during the winter time as well.

01:52 - So, you combine these lower temperatures, um, potentially high winds along with the the shorter days and the ice that comes up here–it makes it a hard place for you to live, particularly if you’re one of the animals here in the park. So what do the animals do? How do they survive this one? Or, what strategies do they use to make it through this harsh period of time? Let’s think about some of them and see if we can’t explore a few. So one class of animals a group of animals that has a particularly hard time during the winter is the amphibians. Animals such as the Shenandoah Salamander or the American toad that live here in Shenandoah National Park really cannot as amphibians regulate their own body temperatures, so they have to find a different extreme strategy on how to survive the coldness of winter. So what they typically do is bury themselves either into the ground or under the leaf litter until they get below frost line, because they can’t freeze or they can’t come back from that so they have to find that place underneath the ground and underneath somewhere that’s below frost line.

So for example, 03:06 - the American toad will dig a little tunnel down into the mud or into the into the soft earth and back up into that tunnel deep enough into the ground that he won’t freeze, and that’s where he sits and stays and lives off his fat during the winter. A salamander does a similar thing, but it’s typically underneath leaf litter and underneath rocks where it can get protected from cold weather. So, the salamanders use that “let’s dig in and find a place to stay for the winter, and, and make it through this cold time till it warms back up.” They typically start doing that in October here in Shenandoah National Park, and they won’t emerge until probably, perhaps around April. So, they spend a long time hunkered down in their in those places.

Some of the frogs, in particular, 03:56 - can even do that under water in the bottom of a pond. How do they do that? Well amphibians are different in that they don’t have to breathe in order to get oxygen. They can absorb oxygen through their skin, so even if they’re under water in a wet environment, they can survive for a long period of time, because they can absorb that oxygen and release carbon dioxide through their skin, which is not what we as humans can do. So that’s how they make it through the winter. The amphibians do so, uh, how do the some of the other animals? Let’s think about something else? Maybe the birds? What do the birds do during the winter time? For example, the red-tailed hawk.

Well, they’ve got kind of a dual strategy to survive winter 04:47 - for them. Some of them are year-round residents, and they stay here throughout the year, as do many bird species, so they they’ll keep their nests; they’ll find a place where they can hunker down; they hunt for the animals that might still be out; and they stay here all winter. However, there’s also the migrating population, which what they do is they head south for the winter. They don’t like the cold weather; they’ll head to the south. So, some red- tailed hawks migrate south. Some red-tailed hawks stay here as year-round residents, and that’s the same way with many of the other bird species here in Shenandoah. They do that.

How do they stay warm if they stay here 05:27 - when it’s really cold? Well, that’s kind of a three-phase strategy that I call “shiver, fluff, and cuddle.” So, birds do shiver just like we do when we get cold, and we shiver that is our body warming itself up by extra energy being expended to warm ourselves up. Well, birds will do the same thing. Some of them will and that’s how they stay warm. They fluff up their feathers. They have all those feathers with down and et cetera on them. So just like your, your fluffy, your puffy jacket that you wear in the winter time, they fluff up their feathers, and that provides warm air space inside next to their body that’s protected by those feathers. And, then the third thing is cuddling. If you go down along the road and you see a bunch of birds sitting on the telephone wire and they’re right next to each other in the winter time, they’re sharing body heat by cuddling close together.

So, that’s a strategy that the birds use in order to survive through the winter is, 06:29 - is to stay put or to fly south, and then to, to cuddle and shiver and fluff during the winter. So while you may see birds flying around here at Shenandoah during the winter time, you’re not likely to see any toads or salamanders out there anywhere. What is the one animal that most people who come to Shenandoah National Park really hope to get to see? Our iconic animal, that’s the American black bear. So what does a black bear do? How does it survive and where does it go during the winter time? Well, they have a different way of doing things. Their, their body systems don’t slow down as much as some animals do.

Their respirations slow down; they’re breathing 07:17 - their, their heart beats slow down, but their body temperature drops very little–only a few degrees, which means that they’re, during their winter time when they’re, when they’re sleeping–I call it “sleepy time”--it’s, uh, they can be aroused very quickly because of that high body temperature that they have. So while they’re in kind of a stupor sort of state, they’re denning up in different places in the park: in hollow trees–is a favorite of theirs–underneath rock overhangs, and sometimes underneath a log that’s laying on the ground or a hollow log inside of one. And, if they can’t find anywhere else, they’ve been known also to just dig a little depression in the soil and lay in that depression and curl up, covering their nose because that’s their most exposed area of their body, and sleep during the winter. So while they’re in that sleepy time, as I call it, they can be aroused fairly quickly, but they don’t usually, and they’ll do that for perhaps three months or so here in Shenandoah National Park, so they’re, they’re out of the picture for a while during that period of time. Amazing thing happens: Babies are born to the moms, and moms hardly even notice it.

They’re sleeping and the babies are so small when they’re born 08:36 - that it hardly even bothers the mom when the babies are born, and they typically won’t even help their babies find their way to nurse, to nurse. How do they do that? The hair on the body on the bottom of the mother on her belly is not as thick as it is elsewhere on her body, so there’s more heat radiating out from that belly. So that’s how the babies find where to go nurse, is by following the heat from their mom. And, so they’ll stay there in the nest or in the den, wherever that happens to be, with mom until spring comes. And, they come out for the for the spring. So that’s what bears do. They also, as do many other mammals, put on some extra fur during that period of time.

It helps them to make it through the winter by having a heavier coat of fur. So, that’s how a black bear makes it through the winter, and what they do while they’re here in Shenandoah National Park over the winter time. So, you’re not going to see those very often either. So those are strategies we’ve looked at and talked about. Amphibians we’ve talked about; birds we’ve talked about; mammals, and the black bear in particular; there’s one other group of inhabitants here in Shenandoah that I know you’re really interested in how do they survive the winter, and that is the park ranger.

Park rangers use all of these strategies to survive the winter. We have the ones that do similar to the birds. Some of them migrate to warmer climates during the winter. They’ll take winter seasonal jobs at places like the Everglades or Death Valley or Joshua Tree, and they spend their winters in those warmer climates, and then they’ll return back here to Shenandoah next summer for a summer seasonal job here. Some of the rangers stay year-round, and while they might be up here at the top of the mountain if the weather permits. Oftentimes, they’re like a toad or a salamander.

10:36 - They’re kind of squirreled away down in the bottom at Headquarters staying as warm as they can, trying to make it through those colder, uh, more brutal periods up here on top of the mountain. And, then there’s that other strategy that, that park rangers use: They hibernate. Some of them, when they’re in their seasonal job, will head back to mom and dad’s house or a friend’s house or somewhere else, and that’s where they’ll spend the winter waiting for that phone call that “hey, next spring we want you back up here on the mountain.” Now, the animals that we talked about usually got fatten up in the fall prior to their hibernation–we call that “hyperplasia.” Rangers on the other hand do just the opposite.

They’re in their best, most fit condition when 11:25 - they finish their six months of working out here, hiking trails, and leading programs, and then they go home and they fatten up while they’re sitting at home at mom and dad’s house waiting for the next call. So, that’s how the rangers survive the winter here in Shenandoah, and if you see one, say hi. So, when you do come to visit just be aware that you’re not going to see as much wildlife as you will other times. You might still see a deer or some squirrels or some birds while you’re here, but you’re not going to see as many people and you’ll enjoy your visit. So, thanks for listening today, and I’ll see you at the park. .