No one can point to a single cause for the plight of mule deer over much of their native range. It's clear to most biologists that several factors came into play. The halcyon days of deer hunting in the West--those two decades following World War II--were marked by conditions unlikely to return. Easy winters still come along often enough; but we don't allow aggressive predator control, including poisons and aerial gunning--common practice back then.

Changes in range management played a part, too. Domestic sheep nibble some of the same bushes deer eat, so heavily trafficked sheep range cannot support large deer herds. On the other hand, brush eradication by ranchers expanding grassland for cattle doesn't benefit deer either.

Then there's hunting. Sportsmen often dismiss their impact on game, pointing out that were it not for hunters, there'd be less wildlife of any kind. Hunters do fund almost all wildlife management and are solely responsible for the twentieth-century revival of most native game species. But some animals do not fare well under the hunting pressure we allow today.