By Marcy Norton

PHILADELPHIA (CBS) — Some key spots in the Fairmount Park system are going to be closed off overnight for a while, because of what the city is calling “deer control activities.”

The deer population is getting out of control, so city officials say it’s time for its annual efforts to “cull” the herd. Translation: they’re bringing in sharp shooters to remove a number of deer. While that’s happening, the public needs to stay out of certain areas for their own safety.

The Wissahickon Valley, West Fairmount Park, Cobbs Creek Park, Tacony Creek Park and Pennypack areas will shut down from 8 p.m. through 6 a.m. every night until the end of March. Parks and Recreation Commissioner Mike Debaradinis says it’s the only way to reduce the herd.

“Unfortunately, because the deer herd does not have any, there’s no predators in there,” he says, “and there’s no way to keep the herd down naturally, we have to resort to this culling.”

Debaradinis says the overpopulation of deer harms the park’s environment because the animals eat tender plants that are important to the ecosystem.