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All About Wolves: Gray Wolves of Yellowstone

The Job of a Wildlife Vet

by Mark R. Johnson, DVM

Mark holds a pup There are many types of wildlife veterinarians. Some wildlife veterinarians work with captive animals at zoos and are zoo veterinarians. Many animals in zoos are being saved from extinction in the wild so the health of every single animal is very important. Zoo veterinarians work with zoo caretakers to keep every animal healthy. Other wildlife veterinarians give veterinary care to injured wild animals and work with wildlife rehabilitation clinics. There are wildlife rehabilitation clinics all over the United States and there is likely one near you that you could visit.

I am a wildlife veterinarian and I work with wild animals that roam free. We call these animals free-ranging wildlife. Instead of giving veterinary care to sick or injured wild animals, I study how healthy they are as a population (group) and I do research to learn how wild animals become sick. I have been a wildlife veterinarian since 1988. That's when I decided to change from doctoring domestic animals, like dogs, cats, sheep, and cows, to working with wild animals such as wolves, mountain lions, bighorn sheep, and elk.

Wildlife biologists capture and handle wild animals to learn about their ecology (where they live, what they eat, and how they live with other animals and plants). This can be very difficult. The animals often become fearful or angry, and can hurt themselves or hurt us when trying to escape or defend themselves. Because it is so difficult, wildlife veterinarians, such as myself, work with wildlife biologists to capture the animals safely and to care for them after they are captured.

In 1991, I began working for the National Park Service in Yellowstone National Park. There were no wolves living in the park, and people were hoping to bring wolves back. I was hired to gather information on how to capture and handle the wolves and how to determine what diseases could make them sick if we brought them to Yellowstone.

In 1995, the U. S. Fish and Wildlife Service and the National Park Service decided to bring wolves to Idaho and Yellowstone Park. They were going to catch about 15 wolves for Yellowstone and 15 wolves for Idaho each year for several years, which is a lot of wolves! I was asked to be the project veterinarian for this gray wolf reintroduction program.

We decided to capture 30 Canadian wolves in 1995 and 1996 and each year transport 15 to a wilderness area in Idaho and 15 to Yellowstone Park. The wolves would be captured in the winter by darting them from a helicopter. The dart contained a chemical that made them sleep (anesthetized). After the wolves were anesthetized, biologists in the helicopter picked them up and brought them to us, where we had a heated garage to work in. Usually it was 30 degrees below zero or colder!

Mark examines a gray wolf pup in a Yellowstone acclimation pen We needed a plan for handling the anesthetized wolves after they were captured so I wrote a handling protocol that was sent to wolf biologists and veterinarians around the country for their comments. The step-by-step protocol described how the veterinarians would first examine the wolf for injuries. The veterinarians also recorded the temperature, pulse, and respiration to make sure they were safely responding to the anesthesia. We took body measurements and looked at their teeth to tell how old each wolf was. We collected blood samples to test for diseases. We also vaccinated each wolf and gave them medications for parasites just as we do for domestic dogs. This was to be sure the wolves we brought to the United States did not bring diseases with them.

After we finished handling each wolf, we took it to a kennel full of loose straw and straw bales. The bales were made into a shelter where the wolf could hide. The chain-link kennel looked just like a backyard dog kennel, but was built much stronger. The kennels were located well away from where we were working so there was little human disturbance.

The wolves stayed in these kennels for several days while we captured other wolves. During this time, the wolves were very afraid, which is very stressful whether you are a wolf or a human. Stress is harmful because it can make animals or people more likely to get sick. To minimize stress, we covered every kennel with tarps so each wolf was in a dark enclosure. We visited the wolves only to give them food and water.

When we had enough wolves to transport to the United States, a large U.S. Forest Service plane came to pick them up. Before the plane arrived, we anesthetized about 15 wolves, the number that could fit in the plane. Each wolf was examined to make sure it had not gotten sick while it was held in the kennels. We also gave more medications to each wolf to prevent them from carrying diseases. Each wolf was placed in an aluminum transport crate specially designed to transport it.

Two veterinarians flew on the airplane to be sure the wolves were okay. We had to go through Canadian customs and then through American customs to be sure all of the proper permits were signed. One veterinarian went with the wolves to Idaho. These wolves were loaded onto a truck and driven closer to the wilderness in Idaho. Then they were flown in a small plane or taken by snowmobile sleds to the release site. There the crates were opened and the wolves were set free.

I went with the wolves to Yellowstone Park. The park rangers picked us up at the airport and it was a very exciting moment when we drove the first wolves into Yellowstone! Instead of immediately releasing the wolves in Yellowstone, like they had in Idaho, they placed the wolves in half-acre pens made of 10-foot-high chain-link fences. The wolves were held in the pens for about 10 weeks to encourage the wolves to stay in the area when they were set free.

These gray wolves were wild and had never been confined before. Would the wolves run into the chain-link? Would they eat the food we gave them or cower and hide? We could not be sure how they would respond.

It turned out the acclimation pens worked very well. For the first two weeks, the wolves chewed on the chain-link to try to escape. After that, the wolves seemed to accept or at least tolerate where they were and even began to howl in the early morning or late evening. We tried to leave the wolves alone as much as possible. When we were not there to feed them, the wolves were by themselves in the acclimation pen, tucked away in a quiet forested area of Yellowstone, soon to be released.

I examined the wolves on Tuesdays and Thursdays when we left them food. I did not handle them because it would have been too stressful. I carefully watched to see if they were lame or had any injuries. I had to treat only one wolf during their time in the pens. One young wolf had cut its mouth while in Canada. We had sutured (sewed closed) the cut, but it had torn its stitches. We anesthetized the wolf in Yellowstone and I resutured its wound.

Mark (on left) puts a new radio collar on a gray wolf at Yellowstone. Now that the Canadian wolves are released in Yellowstone we leave them alone as much as possible. I no longer work for the National Park Service. I am self-employed and I teach wildlife handling courses to university students and wildlife biologists. I still work with the Yellowstone Wolf Recovery Program, though. Occasionally I help them catch and handle wolves or provide veterinary care to an injured wolf. I am also helping them to study diseases in the recovering wolf population.

While your veterinarian determines how diseases affect individual animals, such as your dog or cat, I study how diseases affect a population. When diseases make wild wolves get sick, I not only want to know how the disease affects the wolves, I also want to know how the disease moved through the population of wolves, i.e., how did the disease move from wolf to wolf? Because wolves live in the wild, there are many other types of animals that could carry a disease and then give it to the wolves. To get this information, we collect blood samples from the wolves to study what diseases they may have and we collect blood from other wildlife species, such as coyotes and foxes, to see if they may be carrying the disease and then giving it to the wolves.

As a wildlife veterinarian, I have learned how to capture and handle wild animals as safely as possible so that after we gather information from them and put a radio collar around their neck, we can release them back into the wild in good health. When animals and humans have contact with each other, I try to keep both groups safe. And I try to help animals and humans live together.

Meet Mark Johnson, and read his interview. He answered many questions from students all over.

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