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Name: Steve Thompson
Title: Lead Wildlife Biologist
Organization/Department: National Park Service
Field of study/research:
Wildlife management. We identify wildlife problems or concerns and deal mostly with the management of “problem” animals (bears). The U.S. Fish and Wildlife Service does most of the monitoring and inventory of rare species.

How long have you been doing this?
14 years in Yosemite.

How did you get interested/involved in your field of study?
I have always been interested in wildlife; when I was young I had a [live] reptile collection and an insect collection. I also enjoyed bird watching.

What was your degree in and where did you study?

I actually started out as a business major, and later realized that I had to follow my bliss: watching animals and being outdoors. I got my Bachelor’s degree in Biological Sciences at Sacramento State University and my Masters in Ecology at UC Davis.

For those out there who may have an interest in the study of animals, is there anything you can tell them about how to get a job like yours? Steps to take to put you in the right direction?

Right now the job market is tight. You should make sure to get school and job experience that is directed at working with wildlife.

Before you pursue the field you need to recognize that the job is for the study and science animals: you should not get into the field simply because you think that animals are cute. One should also realize the realities that wildlife management faces. For example, sometimes you have to put down a bear if they are threatening the safety of the public.

Do you like your job? What are some positive and negative aspects of what you do?

I like it because I still get to work with wildlife in a place that I care about, Yosemite. I like handling the animals and being in the field, but now I only get about 12 days out a year because I am the project administrator. The bureaucratic aspects of the job are also frustrating. With a tight budget working for the Park Service, we primarily deal with problem species and cannot monitor rare and endangered species.

Any particularly memorable wildlife encounters (Good or bad)?

The work I do with bighorn sheep is the most enjoyable; it is on beautiful terrain and is challenging to find the animals.

It is also very exciting every time we capture a bear. One time we were in Little Yosemite Valley and heard loud noises in the campground. We went to where the noise was coming from and saw a problem bear swatting at people’s tents. It was the first time that I was scared in a standoff with a bear, because of the bear’s history for swatting and injuring people. I darted the bear and it fell down, tranquilized.

Do you feel that any species need more attention than others? Do you feel that species emotionally appealing to the public, such as bears or mountain lions, get more attention than deserved?

Right now we have 3 of our 4 employees working on bears, which are a “problem” species. There are three main reasons why our work is bear-focused: people feel strongly about the large wildlife like bears, there is a high risk of human injury and we get funding specific for bear research and food storage (we cannot use the funding for other projects).

This leaves only 20% of our funding to go to projects such as monitoring for rare and threatened species, removing non-native species and researching the effects of external forces such as air pollution. It would be nice if we could receive funding to support these other projects. We depend on this type of data from U.S. Geological Survey and university researchers.

What threatened or endangered species live in the park? Is there being anything done to improve their chance for survival?

The loss of native species diversity through extinctions is one of the most important issues that wildlife biologists face. The California red legged frog and the foothill yellow legged frog have already been extirpated from the park.

The mountain yellow legged frog and the Yosemite Toad have suffered an 80% decline in the Park. The frog’s decline was first due to the stocking of fish to Yosemite’s lakes which ended in 1990. The fish ate the tadpoles, and significantly impacted the population size. We now lose about 10% of the remaining mountain yellow legged frog population each year to a disease caused by the kitchrid fungus. The cause of the decline of Yosemite toad populations is unknown, but we are currently studying to see if pesticide drifts from the San Joaquin Valley is a factor. Similar studies on the Pacific tree frog showed a 25% deformity rate due to pesticide drift. We don’t know the threshold contamination level that the Yosemite toad can withstand, but we know that even a little pesticide residue can cause deformities.

The great gray owl, a California endangered species, is also of special concern. Yosemite is the southern most extent of its global range, and the population here is isolated from the closest populations in Oregon and Washington. We would like to research the history of the owl in the Sierras to determine whether the Oregon and Washington populations were ever connected to this population, or if they have recently been isolated from the other populations.

Besides the protection of rare species, what are some of the other important wildlife issues the park faces now?
There are a number of important wildlife issues in the park today.

The presence of non-native species is an ongoing concern. The National Park Service has zero tolerance for non-native species, which compete for food and habitat with native species. Some of the non-native species that are in the park include wild turkeys, bull frogs and white-tailed tarmagins. We have permission to remove these species, but have little funding to do so.

Another important issue is the history of fire suppression and its effect on wildlife. In 1997 there was a high-intensity stand replacement fire in Foresta (in the western park of Yosemite National Park). The fire covered a much larger area and was more intense than natural forest fires. Natural fires burn irregularly, leaving vegetation somewhat undamaged in other places and clearing it in others. These types of fires diversify the number of habitats for wildlife. Currently the Pacific fisher and California spotted owl are two old-growth dependant species that are threatened by fires that burn unnaturally hot. The fisher needs subnivian spaces (spaces under the snow) to burrow in. The spotted owl’s habitat is typified with a high level of canopy closure and large woody debris on the ground, both of which are removed with high intensity fires.

Previously the focus of fire management plan was on forest structure and composition, but we are currently rewriting the management plan that will stress fire management for the enhancement of wildlife habitat. There will be two main zones created in the plan: a fire suppression zone and a wildland fire use zone.

An issue that also would be interesting to study is the effect of regional and global changes on Yosemite’s wildlife. California’s land management of logging, grazing and farming, can affect the air quality and the wildlife that live here. Global warming may also be causing vegetation zones to move uphill as the temperatures slowly rise, which will eventually make wildlife move with it.