Wildlife Tracking at Gold Creek

Figure 1. Tracks of Lepus americanus, the snowshoe hare.

I went on the wildlife tracking field trip, which consisted of hiking through the Gold Creek area in the Cascade Mountains in search of animal tracks. I attended both the February 2nd and February 23rd expeditions. For the former, we arrived at the trailhead at around 1:00pm; the weather was initially a slight drizzle, which increased in intensity as the trip went on but subsided again by the time we returned to the vans around 4:00pm. For the latter, we arrived at approximately 10:00am and left at approximately 3:00pm; the weather was initially a light snow, which became heavier for the majority of the trip then again subsided by the time we left. I chose this trip because I enjoy hiking and the puzzle-like nature of attempting to identify animal tracks. Additionally, as I want to become a wildlife biologist, I reasoned that this would be a useful introduction to the associated field work.

The track shown in Figure 1 is that of Lepus americanus, otherwise known as the snowshoe hare. The general shape of the track, consisting of two roughly parallel hind feet at the front of the track and two staggered front feet at the rear of the track, is characteristic of the order Lagomorpha. The geographical location of the track in the Cascade Mountains, along with the fact that the hind feet are significantly larger than the front feet, means that this track was most likely made by an individual in the species Lepus americanus. The pronounced hind feet of the snowshoe hair represent a significant adaptation for that species. As you may be able to gather from the common name of the species, the snowshoe hare's large hind feet function in a manner similar to snowshoes, in that they increase the organism's surface area in contact with the ground; this in turn distributes the organism's weight across a wider area, allowing it to stand on top of the snow without plunging through it. In the evolutionary history of snowshoe hares, those with smaller hind feet would have fallen further down into the snow with each leap than their large-footed counterparts. They then would have needed to expend more energy to push through the greater volume of snow, draining their energy reserves faster and leaving them vulnerable to freezing, starvation, and predation. Thus, the environment of snowy terrain selected for the evolution of large hind feet in snowshoe hares. This adaptation would have been particularly useful in forested environments such as the one where we found the tracks in Figure 1, as the loosely packed snow in tree wells can easily prove fatal or at least inconvenient for an unprepared animal. Adaptations to conserve energy are visible in the tracks of other organisms as well. In the coyote tracks we followed through the forest, the coyote's hind feet almost always landed in the tracks already made by its front feet, a locomotion pattern known as direct register. This enables the coyote to expend less energy with each step by only stepping with its hind feet on the snow already compacted by its front feet.

Tracking is currently being used to identify animal tracks associated with wildlife corridors crossing I-90. By identifying the types and numbers of animals using wildlife corridors to travel across I-90, it is possible to determine how effective the current corridors are at facilitating safe animal movement and both whether and where additional corridors should be built. The Cascade Citizens Wildlife Monitoring Project is one of the primary organizations conducting this research. This group is a subset of Conservation Northwest, concerned with monitoring the movement of animals--rare species in particular--in association with I-90, as well as spreading this information to relevant officials and organizations, and the public. The citizen scientists of this organization ensure that I-90 effectively caters to the needs of wildlife rather than just benefiting humans.

This trip made me realize how much of an impact something as ubiquitous as roads can have on animal populations. Furthermore, it made me realize how important data gathering can be for practical pursuits outside of the purely academic. The data gathered through track identification plays a vital role in informing policy regarding the design of roads for both economic and ecological benefit. Prior to this trip, I was unaware of the massive amount of research behind the development of wildlife corridors along I-90. Perhaps if this information was more widely known, people would have a greater respect for the work needed to properly maintain precious ecosystems. The most important thing I learned from this trip was that even the existing expanses of preserved wilderness are not sufficient to maintain populations of wildlife when they are fragmented by roads or other aspects of development; efforts must be made to provide animals with the space to move. The most interesting fact I learned was that trees growing at the edge of a forest often have thicker foliage facing the outside of the forest and thinner foliage facing the inside because they receive more light from the side not shaded by other trees.