“They’re pretty famous for finding places to hide acorns,” says Koenig, who has studied the bird for years. Koenig says he once saw a traffic signal stuffed so full of acorns that it was unreadable.

Typically, the acorn woodpecker stores nuts one at a time, digging a small hole in a tree and pushing in a solitary acorn for safe keeping. That keeps it dry and somewhat protected from thieving squirrels. The birds have been known to cache as many as 50,000 individual acorns in a single redwood tree. Occasionally, they’ll put a batch of acorns together in a dead tree or hollow wall (or an antenna), although storing acorns in groups can increase the risk of spoilage from moisture or mold.

People used to think the birds cached acorns in order to harvest grubs that lived on them, but scientists now think the woodpeckers simply eat the nuts.

Acorn woodpeckers have been increasing their range in recent years and are found in much of Central and Northern California, as well as Oregon, Washington, and Colorado, Koenig says. Although people have occasionally tried to get rid of the birds to prevent property damage, the woodpecker has remained resilient.

The owners of the transmitting equipment in the video, AT&T California, say the incident occurred in 2009. The company's technicians shot the video. It's the only time acorn woodpeckers have disrupted the company's transmitting equipment, says spokesperson Jim Greer.