The disease appears here to stayat least for the near future. While male bears seem to gradually recover from the affliction, most females are stuck with it for life.
The high female infection rate also spells trouble for the next generation of bears since infected mothers transmit the mites to their offspring.
Wildlife experts say the affliction causes the bears discomfort but doesn't appear to jeopardize their survival.
"It doesn't really seem to cause them too many problems," Cunningham said. "We don't see secondary bacterial infections, for example, which is a primary problem with mange in dogs. They do get a lot of insect bites in the summer, which can create skin problems. And they are not nearly as well protected from brush and briars."
"They can look pretty rough," Cunningham said. "But they appear to be just as fat and healthy as normal bears elsewhere in the forest."
Disease May be an Indicator of Other Health Problems
Cunningham and other researchers seek to discover if the balding bears really are healthyor if they have other troubles that may be at the root of the disease. Every species of mammal, including humans, commonly has mites specific to that species. These individual mite species do not usually impact the health of the host animal unless that animal has larger health problems.
"The mange could be an indicator of some underlying problem," Cunningham said.
With dogs, such mites proliferate and cause similar problems when there is a problem with the animal's immune system, and that could be the case with Ocala's bears as well.
But theories are currently more common than answers. Cunningham speculates the affected bears could suffer from some type of genetic defect or poisoning from an environmental toxin or that the mites themselves are becoming more aggressive. "It could be a number of things. We really haven't ironed out exactly what," Cunningham said.
Answers Sought in Forests, Laboratories
Cunningham and his team are monitoring the geographic spread of the disease, as well as the fortunes of individual, tagged bears by observation and the use of remote cameras.
The fight is also being pursued in the laboratory, where Disney's Animal Kingdom is pitching in to help assess the condition of the bears' immune systems. Leading the research effort at Disney is Scott Terrell, a veterinary pathologist who likens his job to "a Quincy for animals."
Under his microscope, Terrell examines skin samples for infection, mites, and associated diseases. "We want to see what's it doing to the hair and skin," Terrel said. "Another challenge is to figure out what kind of immune cells the body uses to react to these mites. Hopefully we can someday find out if these animals are immuno-suppressed."
Despite the hard work of reviewing hundreds of biopsies, solutions are elusive. "We still don't know why [the bears] are getting the disease," Terrell said. "We're very much in the investigation phase. We're not treating bears or anything. We're just trying to find out what's going on."
SOURCES AND RELATED WEB SITES