What do moose eat in the winter?

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.

Moose

Ermine

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. 

Ermine


Summer Elk Behavior

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.

Teton Elk
A cow elk walks the bank of the Madison River with her newborn calf.

A cow elk walks the bank of the Madison River with her newborn calf.

Two newborn elk calves prepare to cross the Madison river to join their mothers.

Two newborn elk calves prepare to cross the Madison river to join their mothers.

Winter Wildlife Feature III - River Otters

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. 

Yellowstone River Otters
River Otters Sliding


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.

River Otter Swimming

Winter Wildlife Feature II - Wolves

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. 

Wapiti Wolf Pack
Wapiti Wolves in Yellowstone