Summer is over in the Tetons and Yellowstone, and winter is quickly approaching. The following photos were taken on a single three-day wildlife tour in the parks, and capture the classic autumn behaviors of these animals. I enjoyed taking these photos, and I think you'll enjoy viewing them.

Disclaimer: Some of these photos were taken closer than the 25 yard minimum (or 100 yard for wolves and bears) that is enforced by the park service. I do my best to adhere to these distances whenever it is prudent to do so for the safety of my guests and the animal. The parks depend on our organization as a role-model for responsible wildlife watching. In all cases where we are within 25/100 yards of these animals, the wildlife approached us to feed in nearby habitat. We did not approach them. In many instances, staying put causes less disturbance to the animal than turning on a vehicle, slamming car doors, and maneuvering ourselves outside of the 25/100 yard zone. If the animals are comfortable, the guests are safe, and other onlookers are being respectful, I am happy.

The elk are in the middle of their mating season right now. Males have shed the velvet off their full-sized antlers, and now posture and display them to females, rival males, and human onlookers. Sounds of bugling males fill the woods as they compete for females and defend their harems. The biggest bulls look impressive and intimidating, but spend so much time courting, fighting, defending, and mating, they have little time left to eat food, and enter winter already starving.

Like the elk, bull moose are courting females and showing off their new antlers. Moose don't shepherd harems like elk, and instead follow around females in estrus one-at-a-time, hoping for a chance to mate while fending off all other bulls looking for a chance.

Pika are fattening up for the winter and drying out the the final layer of forbs for their massive haypiles. Once the snow sets in, they will eat from their stored larder all winter long. On the bottom of the pile one might find poisonous or noxious plants that, while not very nutritious, will keep all the way until the end of the winter. The poisonous compounds in these plants are often natural preservatives, so the pika keep these around as a last-resort food source.

The berry season is almost over, and black bears are searching the woods for any remaining hawthorns and snowberries. Here, a black bear has discovered a bush full of fresh rose hips. While not the most nutritious, they are ripe and plentiful, and a welcome food source. Bears must put on 30% of their body weight before hibernation, and have an insatiable appetite as a result.

The trees are turning brilliant yellows and oranges as the green chlorophyll pigments die within the leaves' plant cells. A tree can be torn down by the weight of heavy snow settled on leaves, so these cottonwoods and aspens opt to shed their leaves to prevent permanent damage. Meanwhile, a mother moose feeds on calcium-rich underwater vegetation to recover some of the nutrients she has lost by nursing twin calves all summer long.

Wolves are becoming more active in the prey-rich valleys and meadows of Yellowstone. Elk and bison fight viciously for mating rights, and wolves patrol their territories looking for the injured losers of these fights. We are days away from our first snowstorm, and the wolves look forward to this. Elk are slow and clumsy in the deep and crusty snow, while the giant paws of a wolf act like snowshoes to keep them up on the surface.

A good guide will always be in the right place at the right time to see whatever the park has to offer. This time, the park had a lot to offer.