Cumberland bobcat population dwindling
Mar. 1—It's a rare but memorable experience when a visitor to Cumberland Island National Seashore spots an elusive bobcat.
Researchers captured 32 of the animals from the mainland and reintroduced them to the barrier island in 1989. They have regularly monitored them ever since.
Bobcats were brought to the island as a way to help restore the ecological balance by introducing a natural predator to prey on rabbits, rodents, feral hogs and old or injured deer.
What researchers learned over the years isn't encouraging. The population has dwindled to 24 bobcats and the prediction is they face extinction on the island over time without human intervention.
An ongoing study of the population by Penn State University researchers concedes the study could help predict the extinction of isolated wildlife populations.
While bobcats are not a threatened species, the problem on Cumberland Island is the same facing many threatened and endangered species worldwide: lack of genetic diversity, habitat loss and fragmentation.
Cumberland Island was an ideal location for the study because the island, 17.5 miles long, is accessible by water only.
The study is valuable because the information can be used to help save animals threatened with endangerment because of habitat loss, fragmentation and loss of genetic variation, researchers say.
Since the animals were released on the island more than three decades ago, the population has lost about 15 percent of its genetic diversity. By 2040, the risk of extinction on the island will increase to about 20 percent.
A solution would be to capture a bobcat from the mainland and release it on the island every five years to add more genetic diversity to the population.
"The benefit is we can use this as a case study, or a test case, to figure out what works to re-establish the population's viability, and then that knowledge potentially can be used to extrapolate what would work for an endangered species where the situation is dire," said Cassandra Miller-Butterworth, associate professor of biology at Penn State University.
"If we make a mistake in our calculations on Cumberland Island, it would be sad, but it wouldn't result in losing a species."
