The phantom of the north hunts the tree line during a snow storm at dusk. Great grey owls may sit perched for hours patiently listening for a rustle of movement beneath the snow.
Visitors to the Greater Yellowstone often look at the vast sagebrush and wonder what purpose it serves...other than catching your feet and tripping you on every step. Actually, this ecological community supports a remarkable diversity of wildlife. For example, sage brush flats provide critical winter habitat for moose. Such as the bull moose pictured here browsing on bitterbrush.
Catching a glimpse of these little guys is always a treat...one that never lasts long. This is an ermine. Their coat turns from brown to white each winter, allowing them to be nearly invisible as they move through a snow white landscape. Their tail has a black tip on the end, which functions as a decoy luring any potential predators to strike there, rather than a more vulnerable part of the body.
Bighorn sheep are fairly elusive for most of the year, as they spend most of their time in the mountains. In the winter they are forced down to lower elevations to feed and become much more visible.
A Bald Eagle circles in front of the Teton range to make a second attempt at the raft of coots floating in the lake below.
Bald Eagles key in on waterfowl in the late fall just before the ice takes hold and the open water is gone in Grand Teton National Park. When I arrived at the lake with. I first noticed the group of Red Heads. I looked around a bit more, and I noticed this eagle perched low and just out of sight along the river. I knew it was a matter of time before it made an attempt for the ducks. An hour or so passed and the eagle launched into the air. Flying low and using the topography to its advantage, the eagle had the element of surprise. Even still, it wasn't enough, and after five or six unsuccessful dives the eagle gave up for the afternoon. Nonetheless, it was an adrenaline rush watching the whole event unfold.
While the cow elk are busy raising their young, the bulls stick together in small bachelor herds. Thanks to the nutritious grazing opportunities summer provides, their antlers, covered in velvet, begin regrowing up to an inch per day.
At first glance these slender weasels appear at a serious disadvantage when it comes to keeping warm in the winter. They have practically no body fat, and relatively little fur in their winter coats, but an ermine has several unique features and strategies to make up for it.
For one, their coat turns from brown to white each winter, allowing them to be nearly invisible as they move through a snow white landscape. Their tail has a black tip on the end, which functions as a decoy luring any potential predators to strike there, rather than a more vulnerable part of the body.
To make up for a lack of body fat and extra fur, they generate body heat with their cranked up metabolism. Essentially, they turn their body into a heater, eating up to 6 times a day. When ermines do take time to rest, it needs to be in an insulated location. The den of a chipmunk or vole they just killed fits the bill perfectly. Another tactic ermines are known to employ is actually lining the inside of a log or den with the fur of their victims to keep warm.
There is little question that the next species in my series of winter wildlife finds the most creative ways to have fun. Humans aren’t the only ones enthralled with the feeling of sliding on snow. While we use skis, boards, or sleds, river otters need look no further than their long and slender bodies. When on land, otters cover ground with a hop, hop, slide, hop, hop, slide movement pattern. Sliding on the snow and ice certainly allows them to travel more efficiently, but spend any time with otters and there’s no denying the routine is as much, if not more, for fun as it is for practicality.
Other than playful antics to keep their mind off the cold, otters have some impressive adaptations and strategies for winter survival. River otter’s lengthy guard hairs, and dense underfur, which traps insulating air, keeps them warm in extreme temperatures. On top of that, oil secreted from the sebaceous gland actually waterproofs their coat, preventing water from reaching their skin. To remain well insulated they must replace the air in their underfur after swimming, and they do this by rolling around in the snow, and yes, you’ve guessed it, playfully.
Since the water temperatures are warmer than the air, otters opt to spend more time underwater. They will often travel and hunt underneath the ice shelves which line the rivers and creeks during winter months. An otter may stay below the ice indefinitely by breathing in the air pockets trapped beneath the ice.
While bison display some impressive adaptations for surviving winter, they, along with other ungulates, share one significant disadvantage during the winter, a lack of speed and agility in deep snow. While this may sound more like an inconvenience, it becomes a matter of life and death when your main predator appears to move through the snow as if it wasn’t there. This is the distinct winter advantage of the wolf. Wolves are made for winter. While their prey struggle and sink in the snow, wolves float relatively effortlessly on the surface. Their secret lies in the design of their paws. A wide round shape, and thin webbing between each toe enables each paw to function as a snowshoe. In the search for prey, a pack of wolves, such as Yellowstone's Wapiti pack featured here, may cover 30 snow covered miles in a day. I encountered these wolves recently on one of my photography workshops in Yellowstone. We followed their tracks for miles before catching up to them along them Gibbon River.
Winter in the Greater Yellowstone marries serene beauty and harsh realities in a way only an arctic like cold can. On some days you may be excused for mistakenly thinking you were located in the polar zone. Last January on my photography worksop we spent a day in the field with low temps reaching -40° F (40° C). Severe cold, blustering winds, and limited food resources present supreme challenges for wildlife to overcome. Nothing has kindled a deeper sense of respect for the fortitude and adaptability the inhabitants of this ecosystem posses than my time photographing them in the winter. The next series of posts over the coming days will highlight individual animals and their unique strategies for surviving, and even thriving in the gauntlet of winter.
“In part because bears can be so dangerous, they force you to pay attention. The awe of being in their presence strips away the chaos of thoughts and distractions that normally dominate your consciousness. They focus your attention on the moment. They flood your blood with adrenaline and endorphins…. They introduce you to terror, awe, amazement and ecstasy. They connect you to the deepest pulses of life. This is their gift. The power to take your life, or to renew it; to re-create who you are, if only for a moment, and perhaps for a lifetime.” - Dr. Stephen F. Stringham
With population estimates at one point as high as 50 million, it is hard to believe that in 1902 there were only a couple dozen bison left in the lower 48. If those few survivors were not protected from poaching in Yellowstone, this iconic species would be missing from the Greater Yellowstone landscape.
I caught this large bull, weighing close to 2000 lbs, as he wallowed in the dirt and marked it with his scent. As he shook the dirt off his back the area surrounding him faded into a cloud of dust.