The Yellowstone Diaries: North American Moose

Autumn in the Tetons can be the stuff of legend. The days have been growing shorter for months while the mercury on the thermometer dips lower each week. Chlorophyl production in the aspens and cottonwoods has come to an end entirely and with it the pale green hues of their leaves disappear. Carotenoid and anthocyanin are now revealed. Canary yellows and sunset orange dominate the color pallet of the landscape as snow begins to fall in the high country. Such was the backdrop of my office for the day.

With boots laced tight, I shouldered my pack and began the hike through the sagebrush toward the river. A canister of bear spray swung from my belt as I knew I would be entering a world of low visibility that has the tendency to lure in bears for similar reasons as myself. With autumn, the big mammals of this ecosystem are on the move much like the birds in the sky. As snow accumulates on the mountains, throngs of elk descend into the valley following river bottoms like this one.

But it’s also the rut. A time when tournament species like moose and those same elk begin to battle it out for the hearts and minds of the ladies. Come this time of the year, the males stop eating as they turn their full attention toward the continuation of their genetic line. They drop weight like a prize fighter and will likely lose 30% or more of their body mass before it’s all over.