Habitat loss is being blamed for a decline of California’s deer population by almost half in the last two decades.

A review by The Sacramento Bee shows that while the decline isn’t easily visible due to the size of the state, the numbers of mule deer and blacktail deer have steadily fallen according to the California Department of Fish and Game.

“Our deer are surviving, they’re not thriving,” Craig Stowers, deer program manager at Fish and Game, said in the Bee report. “Quite frankly, until people start taking this seriously, we’re going to continue to experience these types of declines.”

According to the report, “Between 1990 and 2000, according to the U.S. Environmental Protection Agency, 75,000 acres per year were converted to low-density housing across California. A recent Bee analysis of housing data showed a similar trend over the past decade, at least until the recession began. The rate was even greater before 1990.”

The reduction in habitat is responsible for loss of food sources and migration routes.

“You can’t have a good migratory deer population when their wintering ground is covered in residential development for humans,” Stowers said. “They’re competing for the same resources we need, and they’re losing.”

To read the full report, click here.