Media Contacts:
Dr. Phil Doerr, 919/515-2065
Greg Thomas, News Services, 919/515-6098

Nov. 11, 2002

Researchers Go High- and Low-Tech to Study N.C. Black Bears

FOR IMMEDIATE RELEASE

Researchers at North Carolina State University are using a mix of high- and low-tech means of learning important new information about black bear populations in Hyde County, North Carolina.

That area is home to one of the largest populations of black bears in the state, and researchers, conservationists and hunters want to develop and evaluate population estimates for the area - and develop techniques that could contribute to management of bears.

It's not hard to understand why hunters from all over North America come to the coastal plains of North Carolina to hunt bears. The bears there are large; the largest black bear ever taken in North Carolina came from Craven County and tipped the scales at 880 pounds. "It's not uncommon for male black bears in the coastal plains to grow to be 500, 600 or 700 pounds. We're talking about a very healthy group of bears," said Dr. Phil Doerr, professor of zoology at NC State.

It's also not hard to see why black bears flourish in the coastal plains. It's a mix of dense swamps, pine timberlands and farmland with plenty of the foods black bears enjoy. Winter wheat, corn and soybeans provide an abundant and rich diet from April through early winter. In fall and early winter, forested areas contain acorns and numerous berries to "top off the tank" as bears prepare for denning.

Doerr and doctoral student Tim Langer are using a low-tech way of gathering DNA to identify individual bears. Langer has established so-called hair corrals in Hyde County at a rate of about one corral for every square mile. A corral consists of a single strand of barbed wire staked 18 inches off the ground in an 18 feet by 18 feet area. Various chemical scents are placed in the center of the corral to attract bears. When the bears go under or over the barbed wire, clusters of hair are snagged with hair follicles; this is where the DNA samples come from. Follow-up sampling will tell researchers how many bears are in the population.
"Now we can collect hair without having to physically restrain the bear," Doerr says. "That means we can identify each bear from the DNA and estimate population size. In the old days we had to get our hands on the bears and put tags on them to estimate population size."

Doerr and Langer are also using the latest in microprocessors and Global Positioning Satellites to track and record the movements of black bears. Ten bears in Hyde County have been fitted with radio transmitter collars. At pre-determined intervals the collar searches for GPS signals to pinpoint the location of the bear. The collar is programmed to record 4,000 locations in about a six-month period.

The collars are also programmed to fall off at a predetermined time. Tiny devices that connect the two ends of collars are scheduled to separate on Nov. 22. Doerr and Langer will then use a hand-held radio receiver to track down the collars for collection. If for some reason the collar does not fall off as planned, cloth sections of the collar will disintegrate, allowing the collar to fall off later. The invaluable information from the computer in the collar will let researchers know where the bears are, and when; how fast they move; what habitats they use; and their locations relative to the hair corrals and other human activity.

The N. C. Wildlife Resources Commission (NCWRC), the state agency charged with managing resident wildlife such as black bears, is funding the DNA research in cooperation with NC State. The NCWRC already constructs regionwide population models based on age structure and reproductive data collected from their extensive monitoring program. The agency is interested in developing new methods that may enhance these efforts, which explains their interest in supporting the new study. Reflecting public interest in bears, additional money for the study has come from numerous private donors.

The two NC State biologists expect to continue the Hyde County study for the next two years. "The bears of Hyde County have a lot to teach us," Doerr says.

- thomas -