Tuesday, February 25, 2014

Don't Do It! Don't Investigate The Wiggly Thing!

It lays curled on top of the snow, silent and motionless except for the end of it's tail. From across the snow alert eyes of a mouse see something small and back moving on the snow's surface. Could it be food? The mouse creeps in closer and closer until WHAM! Sharp canine teeth sink into it's neck snuffing out the mouse's life. Mouse in teeth the critter scurries back to it's den, inside is the fur and feathers of other unsuspecting creatures; ptarmigan, marmots, snowshoe hare, and weasels.

Who is this terrifying predator roaming the woods you wonder. None other than this guy, the ermine.






You were thinking some HUGE predator something like a coyote or fox weren't you. He maybe small but he shouldn't be overlooked or dismissed as some cute little furry creature. Ermines are one fierce predator taking on prey as large as a snowshoe hare or something as small as a mouse.       

These cunning carnivores often are seen hunting in a zig-zag pattern leaping over a foot in each jump, which is mighty impressive for a critter that is only 6-12 inches long. They use their keen sense of smell to locate their prey by investigating every hole, crevice, and cave in the rocks. In the winter if the snow is too deep they will tunnel into the subnivian layer, or under the snow to those non-scientists out there, and move around in tunnels looking for prey.  They will even flick their tail with it's small black tip in order to lure prey in closer, their white body perfectly camouflaged against the stark white snow.

In the spring these crafty little critters change color to be white on their belly and brown on top.  (Science moment: The increasing light levels in the spring trigger a hormonal change which causes their fur to gradually fall out leaving changing them from white to brown. The same thing happens in the fall. As the days shorten the hormonal change is triggered and the fur changes from brown to white.) Their high metabolism means they have to eat every day, so to make sure they always have a meal ready even when they can not catch one. They cache dead things in hole so there is always something to eat.

Look hard the next time your out in the snow and see if there are two small eyes starting back at you.

If you want to see some other cute ermine pictures check out Meg Sommers' web page she just captured some amazing photographs of an ermine in Yellowstone National Park. 

Tuesday, February 18, 2014

Cool Stuff You Never Knew About Snow!

Snow everybody's favorite four letter word has been falling a lot lately even in places where snow is a whole new concept. Well, I've been pondering snow, walking in snow, snowshoeing in snow, post-holing in snow up to my waist a bunch recently. So, here are three interesting facts I have learned about snow over the last few weeks as I prepared to teach an advanced snow science class.




1) It doesn't need to be warm to melt snow.
The temperature here in Colorado has been all over the map, 50 degrees one day 20 degrees the next with a lovely (said with a huge amount of sarcasm) wind. I was pondering the snow fluctuations recorded by our SNOTEL trying to get a handle on why if we get 241 inches of snow (that's a little over 20 feet) in an average year (October to June) why there never seems to be more than about 41-70 inches at any one time at the SNOTEL gauge?  The obvious answer is it melts. The only thing is while it can be 50 degrees at my house at the SNOTEL site, 3,000 feet above my house, the temperature ranged from 24-31 degrees Fahrenheit. So where the heck is all the snow going? Sublimation is the answer!  The constant 30-60 mile per hour winds are causing the snow to go straight from a solid into a gas without needing to melt first. A scientific paper I read showed the snow pack in the research location, not too far from where I work, decreased by 15% each year just due to sublimation.


2) Fresh power makes my eyes hurt!
Ever wonder why it seems brighter right after a light fluffy snow falls than a few days later?  Freshly fallen snow has the ability to reflect 90% of the solar rays which hit it's surface. After a few days when the snow has a chance to compact it looses some of its ability to reflect sunlight and only can reflect about 50% f the sunlight hitting it.


3) Best Insulation Ever!
There is naturally a small amount of heat radiating up from under the surface if the ground. Build yourself a snow cave and you can trap some of that radiating heat to help keep yourself warm.  Small animals, such as mice, have figured this out. While the surface of the snow maybe frozen solid the natural heat radiating from the ground causes the lower layers to melt slightly changing the shape of the ice crystals. This new crystal shape looks like sugar grains, hence the name sugar snow, this snow is much easier for small critters to move through than the hard wind packed snow on the surface.