Mysterious Decline in California Blacktail Population

From this story (via the Hog Blog) in the San Francisco Chronicle:
The distinctive splayed antlers of black-tailed deer bucks have become an increasingly rare sight in California, particularly if you are accustomed to spotting the appendages through a rifle scope.The California deer population has plummeted over the past two decades - by 46 percent - if the yearly count of bucks killed by hunters is a proper measure. A team of scientists led by the California Department of Fish and Game is fanning out across the rugged mountains of Mendocino, Glenn and Lake counties in an attempt to figure out just what is going on. "The deer population harvest has been steadily declining," said David Casady, an associate wildlife biologist for the Department of Fish and Game. "One of the things we're studying is whether the population has decreased or just the harvest. Most likely it's the population that has decreased and the harvest is just tracking that."