November 11, 2009
Skunk’s Strategy Not Just Black And White
Predators with experience of skunks avoid them both because of their black-and-white coloration and their distinctive body shape, according to UC Davis wildlife researcher Jennifer Hunter. The study was published online Oct. 21 in the journal Behavioral Ecology.
Hunter wanted to know how predators know a skunk is a skunk. Biologists had assumed that the distinctive black-and-white color scheme was a marker saying, "keep away."Hunter prepared taxidermy mounts of skunks and of gray foxes, an animal about the same size but a distinctly different shape. Some of the stuffed skunks she dyed gray, and some of the foxes she dyed black-and-white. She then placed the animals at 10 sites around California -- in locations where skunks were abundant as well in areas where they were uncommon -- and monitored them with infrared video cameras.
In locations where wild skunks were not commonly found, predators such as bears, mountain lions, bobcats and coyotes would approach, lick, roll on or attempt to drag away the stuffed skunks as well as the stuffed foxes. But in places where skunks were common, potential predators gave anything skunk-like, either in shape or color, a wide berth.
"They wouldn't go near them," Hunter said.
The results suggest a much stronger learning component in prey recognition than was previously thought, Hunter said. She was also surprised to find that body shape, not just color, was important. Previous studies, mostly conducted in the laboratory rather than in the wild, had suggested that animals have an inbuilt tendency to avoid brightly colored or multicolored prey.
The study also raises the question: Does anything actually eat skunks? Possibly not, Hunter thinks.
While numbers of most animals are controlled by predators above them in the food chain, skunks may be a rare example where the main check on their numbers comes from disease, food supply or lack of habitat -- factors that depend mainly on the number of skunks themselves.
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