Managing non-native animals

A capuchin monkey captured in the park.

A capuchin monkey was one of many non-native species captured in the Smokies.

NPS photo.

People bring many non-native animals into the Park (or the animals escape and bring themselves here). Managers have come across emus, peacocks, pheasants, a de-clawed black bear, dairy cows, a long horned cow, a gray wolf hybrid, and a capuchin monkey wandering in the national park. Unfortunately, some people also drop their unwanted pets at the boundaries of Parks, thinking they’re “setting them free.” But kittens and dogs don’t survive long in the wild; if they’re not hit by cars, they’re gobbled up by coyotes. Wildlife managers are worried most about the animals that people release into the Park and that readily adapt and thrive. These species are invasive--meaning they take over habitat or food sources from native animals--and if they establish themselves here, they can sometimes pass disease to the Park’s native wildlife.
Hog in trap.

A hog caught in one of many traps you see in the Smoky Mountains.

NPS photo.

Hogs are the most worrisome of these non-native species. Hogs root out native plants and destroy streambanks (and with them, habitat for salamanders, trout, and other sensitive wildlife). They can also carry disease, including swine brucellosis, pseudorabies, and hog cholera (classic swine fever). Pseudorabies, also called “the mad itch,” is not rabies, but rather a form of herpes similar to chicken pox in people. Just like chicken pox, it’s highly contagious. To wild canines, including our coyotes and foxes, the disease is fatal, so wildlife managers want to ensure that they eliminate as many hogs as possible. In addition to carrying disease, hogs are like huge plows: they root under the soil looking for food, and destroy large areas of forest and field habitat.

Hogs are not native. The hogs you might come across in the Smokies today are from two main sources. The first source has resulted in a shaggy black hog that looks like a traditional European wild boar. In the early 1900s, a local rancher brought about two dozen pure European wild boars to North Carolina to stock his hunting ranch. The boars were wily and about 60 to 100 escaped. Over time they interbred with feral hogs, domestic stock of local farmers that also roamed freely in the mountains. In the past century they have spread throughout the mountainous forests of western North Carolina and eastern Tennessee.

A hybrid hog with pink spots.

Some captured hogs have pink spots and curly tails, and look quite different from the dark, shaggy hogs that we usually find in the Park.

NPS photo.

Hogs that look very different from these black boars also appear. These hogs often have spots and sometimes even have curly tails. People presumably brought these hogs from other states and deliberately released them in the Park so they could hunt them.

What do we do with non-native wildlife? In a typical year, wildlife managers actively trap and shoot wild hogs to stop habitat destruction and disease spread. Most of the work is done from December through June. In a typical winter, wild hogs move to the lower elevation areas where wildlife managers can more easily access them. In the spring and throughout the summer, hogs move to the higher elevation forest in the backcountry, making hog control much more difficult. In a typical year managers remove about 275 hogs from the Park—slightly more than half of those on the North Carolina side.

Wildlife managers also work cooperatively with the North Carolina Department of Agriculture and Consumer Services, the USDA, Animal and Plant Health Inspection Service, and the Tennessee Department of Agriculture to monitor for wild hog disease and disease spread. These studies include taking blood samples from captured hogs and keeping track of capture locations.

Other invasive animals are also problems for the Park, but many of these—the hemlock woolly adelgid and fire ant, to name a couple—are challenges that vegetation managers handle.

Return to Meet the Managers: Wildlife.

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