UT's Energy, Environment
and Resources Center Presents
Smoky Mountain
Resource Issues in Great Smoky Mountains National Park
SIGHTLINE
FALL/WINTER 2002
Vol. 3 No. 2
***
Editor: David Brill; Assistant Editor: Constance Griffith; Writers: Kris Christen, Lisa Byerley Gary, Elise LeQuire, Dennis McCarthy, and Becky Nichols. Graphic Designer: Lisa Byerley Gary.
SIGHTLINE is published on behalf of
Great Smoky Mountains National
Park
by the
Energy, Environment and Resources
Center (EERC)
at the
University of Tennessee.
EERC conducts research designed to promote real-world solutions to problems in the fields of energy, environment, technology, and economic development.
For additional information, write EERC, 311 Conference Center Building, The University of Tennessee, Knoxville, TN 37996-4134, call 865-974-4251, or visit our Web site at http://eerc.ra.utk.edu.
SIGHTLINE is sponsored by:
and
Otter Success
River
otters, whose populations once dwindled because of trapping and habitat
loss, are once again thriving in the waters of the Smokies.
by Kris Christen
Like a nervous bridal couple, this pair of otters stands before a creekside altar.
Prized for their handsome pelts, river otters were nearly extirpated from the area now known as Great Smoky Mountains National Park (GSMNP) by the 1930s. What the trappers didn’t get, habitat destruction in and around current Park boundaries did, says Bill Stiver, a Park Service wildlife biologist. Extensive logging throughout the area led to runoff that silted up many streams, smothering the aquatic life that otters had depended on for food. Until recently, the last reported sighting of native otters inside the Park occurred in 1936, according to the Park Service.
Thanks to reintroduction efforts begun in 1986, however, the animal has staged an impressive comeback, and the Park now hosts a thriving population, says Kim DeLozier, a supervisory wildlife biologist stationed in GSMNP. Though DeLozier won’t hazard a guess at the current number of otters in the Park, he says that the population is nearing the carrying capacity of the Park’s ecosystems. Recent and ongoing efforts to restore red wolf and elk populations to the Park were undertaken largely as a result of the successful reintroductions of the otter and peregrine falcon.
Before the otter reintroduction project got underway, the Park Service wasn’t certain that the species could be restored, DeLozier admits. As a result of timber overharvesting and destruction of riparian areas, river otters had suffered severe population declines throughout their North American range, surviving only in less-developed coastal and wetland areas, and there was little data available on their habitat requirements, social structure, and adaptability to a changing environment.
Studies in Feasibility
To find out if otters could survive in the mountains again, Park scientists decided to try a couple of experimental releases, monitor their success, and let the animals determine the suitability of the Park’s habitat, according to DeLozier.
These studies involved two University of Tennessee (UT) graduate students who undertook the research as part of their master’s thesis work. The first study began in 1986 with the release of 11 otters in the Abrams Creek area, and the second followed in 1989 with the release of 14 otters in the Little River area above Elkmont. The Park Service acquired the released otters from North and South Carolina. The animals were a subspecies of the native Smoky Mountain river otter that had been lost, says Mary Dodson, who conducted the second study and is now a wildlife biologist with the U.S. Forest Service stationed in Cherokee National Forest.
All of the animals were outfitted with radio transmitters. Data obtained through radio telemetry and excrement, or scat, analyses indicated that they successfully fed, located other otters, and established home ranges in and around the creeks where they had been released. Researchers identified crayfish as the otters’ food source of choice, followed by fish, which are available throughout the year and in greater volume, according to the first study. White suckers, northern hogsuckers, stonerollers, and creek chubs—all all of which are slow swimming fish—were the species identified most often in otter scat.
The researchers noted that individual otters demonstrated unique behavior, says Dodson, with some moving around quite a lot, and others very little. “One or two wandered outside the Park, but most of them stayed within the Park boundaries.”
Overall, the research projects were deemed a success. “We essentially got the information we needed to know—that most of these otters would stay in the creeks we put them in and would survive and reproduce,” DeLozier says. Consequently, the Park Service decided to go ahead with a full-scale restoration project and in 1994 released 100 more otters into waters on both the Tennessee and North Carolina sides of GSMNP.
At about the same time, the Tennessee Wildlife Resources Agency (TWRA) and North Carolina Wildlife Resources Commission (NCWRC) went forward with otter restoration projects of their own. Using the baseline information gleaned from the first UT thesis study, TWRA released more than 300 otters into rivers in Middle and East Tennessee during the late 1980s, says Doug Scott, a TWRA wildlife biologist. NCWRC released close to 300 otters into 11 rivers in western North Carolina from 1992 to 1995, according to Mike Carraway, an NCWRC wildlife biologist. The agency trapped the animals on the state’s coastal plain, where otters were more abundant, before relocating them in the Smokies.
Measuring Success
Despite the fact that no systematic follow-up studies were ever conducted, the Park and both state agencies are certain the otters have done well based on the frequent sightings of otters with young in a number of different streams.
“We see otters all the time now, and they’ve apparently reoccupied waters outside the Park as well,” which likely constitute a better habitat than many of the high-elevation streams found inside the Park, DeLozier says. The larger water bodies outside the Park have slower moving currents, which enhances the habitat for bottom-feeding crayfish and fish such as suckers and sculpins—prime otter prey.
Also confirming their successful reintroduction is the fact that otters have become an occasional nuisance, cleaning out some fish ponds and pilfering minnows from bait shops or minnow buckets. Although they normally won’t feed on faster moving fish like trout or crappy, otters will search out other food sources during periods of low food availability, such as January and February when crayfish aren’t available, DeLozier says. “They’re very resourceful.”
A few otters have also reportedly been hit by cars between Gatlinburg and Pigeon Forge, Dodson notes, and “once you start getting road kills, you know they have to be doing pretty well, because that’s an unusual thing [when populations are down].”
TWRA and NCWRC, looking for scat, tracks, and feeding sites in areas where the otters have been released, have found otters in every stream they’ve surveyed. “As far as we can tell, the otters have done well everywhere we’ve released them,” Carraway says.
In fact, the Tennessee program has been so successful that TWRA has labeled otters a legal game species in East Tennessee. The trapping season opens November 22 and closes February 15, with a limit of four otters per permit, according to TWRA’s Scott. North Carolina isn’t quite so far along in the western part of the state, but hopes to do the same before long, Carraway says.
Lessons Learned
Restoring the otter to its native habitat has also improved stream health by creating a more robust river ecosystem, DeLozier says. “These animals go after fish that are dead or sick; essentially fish that are easier to catch.” Moreover, they add a lot to Park aesthetics, in that otters are a species most people enjoy and don’t feel threatened by, unlike the red wolf. “They always seem to be playful, enjoying what they do, and I think a lot of people are pleased with that.”
Park researchers have found that the otters succeeded where the red wolf project failed largely because their young survived whereas the wolf pups didn’t. “We can speculate as to why and say it was because of disease—whether parvovirus or distemper—but we never confirmed that 100 percent,” DeLozier says. Moreover, the wolves tended to roam much further distances than the otters, moving outside Park boundaries and running with coyotes.
Although otters, like the red wolf, are also predators, they’re much smaller animals and not nearly as visible, Dodson says. “Because most of the otters stayed in the Park, you didn’t have a lot of trouble. Plus, I think the otters have a larger food base—plenty of fish—than what the wolves found.”
So with no natural
pressures, the otters’ continued success seems assured for now.
For more information, contact Bill Stiver, Great Smoky Mountains National Park, 107 Park Headquarters Road, Gatlinburg, TN 37738, or call 865-436-1251.