Posts Categorized: Science You’re Super

Can’t We Just Hibernate?!

Science, You’re Super: Hibernation!

By Aryn Henning Nichols • Originally published in the Winter 2014-15 Inspire(d)

Winter. Gah! Lots of us want to just burrow under the covers and stay there until the snow has passed. But sadly, that’s not a reality for humans (foiled again!). For some creatures, though, it’s perfectly normal to spend the cold, dark season curled up in the fetal position (okay, super deep sleep). Not because they hate winter, but because food is scarce, making it necessary to reserve energy so they can make it out alive. These creatures hibernate. (1)

There’s a debate about whether certain animals hibernate or actually go into torpor. Hibernation is a long-term state in which body temperature is significantly decreased, metabolism slows drastically, and the animal enters a sleep so deep that would take some time to recover if woken. The black bear’s body temperature, for example, only drops a few a degrees, so many might define that as torpor

Torpor is sometimes used as an umbrella term to describe all the various – big or small – types of temperature- and metabolism-reducing functions. (2)

For the sake of simplicity (and because it’s more fun to say), we’ll just call it hibernation in this story.

Hibernation is not really sleeping at all. As we already mentioned, there are some major physiological changes a body must go through to achieve hibernation:

  1. Drop in temperature. The average temperature of a hibernating mammal is 63 degrees!
  2. Slowed heart rate and breathing. For example, chipmunks go from a 200-beat/minute heart rate to a five-beat/minute rate! And bats can drop down to just one breath/hour!
  3. Greatly diminished consciousness. It takes some time and a lot of energy for a hibernating creature to come back to full consciousness. So much so, that waking one during it’s winter slumber could mean death for them that winter or spring because of the unplanned expense of energy. (1)

Those physiological changes are controlled by the endocrine system. This system runs the glands in the body that adjust the amount of hormones being released. The

thyroid gland heads up metabolism and activity levels, the hormone melatonin controls the growth of winter coats, the pituitary gland maintains fat build-up, heart and breathing rate, as well as metabolism, and, finally, the hormone insulin regulates the amount of glucose (sugar) needed by the animal (1)

While in hibernation, the temperature of a mammal’s habitat will affect its body temperature – much like a cold-blooded animal. But there is a minimum temperature, known as a set point, which acts like a sort of alarm system. When the creature’s body temp reaches the set point, metabolism turns up and burns fat reserves, which creates energy that is used to heat systems back to the set point. (1)

But what about when they have to go…you know? Interesting fact: Bears don’t urinate all winter. They break their urea down into amino acids. And even though they don’t drink, they don’t get dehydrated either. They’re able to extract enough water from their own body fat to stay hydrated. (3)

Although humans don’t hibernate, a nice long sleep (but not too long) is full of benefits for us as well:

Lowers stress
Improve moods
Helps you maintain a healthy weight
Improves athletic performance and coordination
Improves memory and attention span
Live longer and healthier lives (4)

So while it’s impossible to sleep the entire winter away (and you shouldn’t want to – there are lots of great things to do this winter for you – check out page 34 for ideas), taking advantage of the longer evenings with an extra hour of sleep is a great idea. They don’t call it beauty sleep for nothing!

Check out the Hibernation Infographic below for more amazing stuff about hibernation, the creatures that do it, and what we humans can gain from some more sleep as well. Zzzzzzzzz…

  1. animals.howstuffworks.com/animal-facts/hibernation1.htm
  2. en.wikipedia.org/wiki/Hibernation
  3. www.pbs.org/wgbh/nova/nature/bear-essentials-of-hibernation.html
  4. www.better-sleep-better-life.com/benefits-of-sleep.html
SleepInfographic_Winter14_15

5 Reasons to Love Winter

Snow

Five Science-y Reasons to stop giving winter the side-eye. Love and hate ride such a thin line, right? Let’s embrace it and try to love winter!

1. You can walk on water
When temps get to 32 degrees Fahrenheit or lower, the lakes, streams, and rivers in the area start to freeze. That means that – once the appropriate thickness is achieved – you can walk on water (<– ‘cause it’s ice). How thick does the ice need to be? Well, new, clear, solid ice needs to be four inches thick before you can walk on it, and white ice, sometimes called “snow ice,” is only about half as strong as new clear ice, so the thickness there should be – you got it: eight inches. But many factors other than thickness can cause ice to be unsafe, so no matter what, you should always check the ice first – learn how here: www.dnr.state.mn.us/safety/ice/thickness.html

 2. The sky literally falls
Snow is really just clouds falling from the sky. Because clouds are really just floating water. (You can see last winter’s Science You’re Super: SNOW! at theinspiredmedia.com for details on snow and how it works).

But do you know just how big snowflakes can get? The largest snowflake recorded in the Guinness World Book of Records fell on January 28, 1887, in Ft. Keogh, Montana. It was 15 inches across and 8 inches thick! The runner up was one that fell in Bratsk, Siberia, almost a hundred years later in 1971 – but it was a mere 8 by 12 inches.
en.wikipedia.org/wiki/Snowflake

3. The stars are brighter
Well, they SEEM brighter, anyway. From the Northern Hemisphere in the winter we’re looking toward many less more stars than in the summer.

The hazy quality of the summer sky is caused by the combined light of billions of stars in the direction of the Milky Way’s center. In winter, we’re looking less directly into the galaxy, the winter stars tend to be closer to us, and there are also some really big stars located in this direction. So we’re seeing fewer stars, but are looking more deeply into the space beyond the Milky Way, making the winter sky seems sharp and clear compared to a summer sky! earthsky.org/space/star-seasonal-appearance-brightness

LoveMeNorwegianThea

4. You burn more calories
Okay, it’s a negligible amount, and you don’t want to spend your whole day shivering, but if you’re cold enough to shiver you’re actually burning a few extra calories as your body works to keep warm. Unfortunately, exercising in the cold doesn’t really make you max out the burn any more – your body, when it’s worked up during a good jog, ski, hike, does a good job of keeping you warm .
www.huffingtonpost.com/2011/11/16/calories-cold-weather_n_1096331.html

5. Snowmen, Snow forts, Snow angels, Snow balls
Because it stays cold enough for water vapor to freeze and fall, but not always warm enough for it to melt once it hits the ground, we’re able to make fun stuff with all that white stuff! C’mon. Don’t forget just how great it is to get all bundled up and head outside to play in that winter wonderland.
maps.howstuffworks.com/united-states-winter-temperatures-map.htm

RoxieSnow

Science, You’re Super: Bird Migration

Geese

By Aryn Henning Nichols • Photo by Joyce Meyer Photography
Originally published in the Fall 2012 Inspire(d)

It’s a familiar fall scene: you hear the honking first, then see the v-shaped flock fly over – geese heading to some exotic locale for the winter. It’s obvious why “snow birds” – ironically human – head to warmer climes to avoid the frigid Northern winters, but what about these birds? Why do they migrate back and forth each year, and how do they even know where they’re going?

Approximately 1,800 of the world’s 10,000 bird species take this annual, large-scale movement between their breeding or nesting (summer) homes to their non-breeding (winter) homes each year. (1) Like many things in life, food is the main motivating factor. Birds that nest in the northern hemisphere hang out in the spring to take advantage of the plentiful insect populations, budding plants, and large quantity of places to set up “nest”. As winter sets in and the availability of insects and other food options declines, the birds head south – simple as that. (2) Many of these birds that breed in North America migrate to areas south of the Tropic of Cancer (Southern Mexico, Central and South America and the Lesser and Greater Antilles in the Caribbean Sea) in the fall (August-October) and then winter there until April when they head back to their old stomping grounds up North to breed and raise young. (3)

There are three different types of bird migration: short (moving from a higher to lower elevation on a mountainside), medium (moving a distance that spans several states) and long-distance (generally moving from the northern hemisphere to the southern hemisphere). For short-distance migrants, the reason really is as simple as a need for available food. But the origins of long-distance migration are a little more complicated. What “tips” the birds off that it’s time to get moving varies – days getting shorter and colder, dwindling food supplies, or it even something in their genetic predisposition. (2)

In the period before migration, many birds display higher activity or Zugunruhe – German for “migratory restlessness”. Even cage-raised birds with no environmental cues (e.g. shortening of day and falling temperature) show signs of Zugunruhe, further leading scientists to believe migratory tendencies might be genetically predisposed. (1)

Birds also eat more food pre-migration, storing it as fat. Fat is normally three to five percent of the bird’s mass, but some will almost double their body weights as they pack it on for the trip! The ruby-throated hummingbird, for example, weighs only 4.8 grams but can use stored fat to fuel a non-stop, 24-hour flight across a 600-mile stretch of open water from the U.S. Gulf coast to the Yucatan Peninsula of Mexico! But most songbirds don’t fly to their non-breeding grounds non-stop. They stop a number of times to rest and feed in places called stopover sites. Some birds stop only one day to rest and feed, and then continue their migration. Others will remain at stopover areas for weeks, storing up more fat. The arctic tern may hold the longest distance migration, made possible because they stop over various places to eat fish and feed along the way. The tern migrates about 18,600 miles each year! Amazing! (3)

It’s not just the distance traveled that is amazing, though – the “how” of the travel is pretty wild too. They don’t come equipped with GPS, but somehow migrating birds can cover thousands of miles, often on the same exact “bird highway”, year after year. Even first year birds may migrate – without a guide – to a winter home they have never before seen and return in the spring to their birth land. (2) They use the age-old compasses in the sky to navigate the way – the sun and stars – and also something really cool: the Earth’s magnetic field! Yes, you read that right! Birds apparently have tiny grains of the mineral magnetite just above their nostrils, which helps them find what direction is true north by using the Earth’s magnetic field.

Beyond that, day flyers navigate using the positions of the sun and night flyers find their way by following the patterns of the stars. And – get this: In their very first year of life, those birds memorize the position of the constellations in relation to the North Star! Some birds can also use their sense of small to help find the way. (3)

Many, if not most, birds migrate in flocks, which for larger birds, can conserve energy. Geese save from 12 to 20 percent of the energy they would need to fly alone – and some even fly faster in flock formation! (1)

In the spring, we’ll see them heading back up the “road” home, and now, when you gaze up at the first honk, know it might even be the same exact birds you saw this fall!

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Aryn Henning Nichols was constantly amazed as she researched this Science, You’re Super. How cool are migrating birds?!?

References:

  1. http://en.wikipedia.org/wiki/Bird_migration
  2. http://www.birds.cornell.edu/AllAboutBirds/studying/migration/
  3. http://www.zoosociety.org/conservation/bwb-asf/library/BirdMigrationFacts.php