for National Geographic News
The appearance of hairless black bears has become common on the western edge of Florida's Ocala National Forestand the animals are not a pretty sight.
"My heart goes out to these bears," local resident Guy Marwick said earlier this week. "It was 27 degrees [Fahrenheit (-2.7° Celsius)] here this morning. The females are trying to den up, and they are doing it in cold soil with no insulation."
Marwick's property borders the national forest, where he's been observing bears for over 30 years. He first began noticing balding bears in 1999. "I'm really concerned," he said. "Without the fur, the thickets and vines are really working on their skin. They are a bizarre and pitiful sight."
The dramatic hair loss is caused by mange, a condition spurred by an outbreak of mites. Researchers seek to learn the cause of the mite outbreak, which they say may be an indicator of some larger health problem affecting the bears. What that underlying problem may be, however, has proven to be frustratingly elusive to wildlife biologists.
Since their first sighting in 1990, hairless bears soon began appearing more and more frequently, always in the same general area of the Ocala National Forest.
"What we kept seeing was bears showing up as road kill on the western edge of the Ocala Forest," said Mark Cunningham, a veterinarian with the Florida Fish and Wildlife Conservation Commission who has been tracking the disease for years. "They were found in a relatively small area centered on the town of Lynne. Compared to the rest of the forest, it's a smaller, fragmented area with development interspersed with woods."
To date, the infection appears to be contained to an area on the western edge of the forest. "We don't really know if it's spreading, but it's certainly not going away." Cunningham said.
Cunningham cautioned that some recent media coverage has overstated the scope of the crisis. "Numbers-wise, the problem is not that large," Cunningham told National Geographic News.
However, the bears living in the affected area have been hit hard.
Roughly 50 percent of the area's bears have the disease, including over 80 percent of the adult females. Even the few females that don't currently exhibit the mange-like symptoms show signs of previous infection.
Threat to Bear Health Appears Minimal
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