Rare gray fox sighting in San Francisco’s Presidio

A close-up of the unexpected gray fox seen in the Presidio, above Baker Beach, last week. A close-up of the unexpected gray fox seen in the Presidio, above Baker Beach, last week. Image 1 of / 3 Caption Close Rare gray fox sighting in San Francisco’s Presidio 1 / 3 Back to Gallery

When coyotes resurfaced in San Francisco in recent years, it was all over for the fox — or so they said.

The nearly forgotten gray fox, however, was spotted last week evading its canine predator in the Presidio, the first confirmed sighting of the animal in the area in a decade.

“We thought they were all gone,” said Dana Polk, a spokeswoman for the Presidio Trust. “This is a big deal.”

As a result, Presidio Trust officials, who manage the former military post now run as a national park, are relaunching efforts to monitor the gray fox in hopes of better understanding the creature.

The discovery of the fox — which is fairly common in rural California, but was believed snuffed out of San Francisco by rising coyote numbers in the early 2000s — was made by a Presidio Trust scientist last Wednesday.

Jonathan Young, a wildlife ecologist, had tracked a pair of coyotes from his office at Fort Winfield Scott near Baker Beach when he noticed one of the canines perking up a bit.

As he moved in for a closer look, Young noticed a gray fox in a tree near the Batteries to Bluffs Trail, likely having climbed there to escape the coyotes.

“It definitely took me by surprise,” said Young, who documented the sighting by taking pictures on his iPhone through binoculars. “I would have stayed around and photographed more, but I had a meeting.”

Young said the coyotes eventually lost interest in the fox. But Young didn’t.

He and his colleagues are planning to set up remotely operated cameras to see if there are additional foxes in the Presidio — and they’re asking the public to report sightings through the phone app iNaturalist.

“Hopefully, through time we’ll be able to track this thing and get a better idea of what is actually happening,” Young said.

Until then, two theories may explain the sighting, Presidio officials said.

It’s possible that a small number of foxes survived the coyote influx all these years. Or, it may be that this fox, and perhaps others, occasionally migrate to the Presidio, either crossing the Golden Gate Bridge or heading north from Ocean Beach and Golden Gate Park.

The gray fox is a nocturnal animal that feeds on mice, rats and rabbits. The animal typically weighs up to 15 pounds and is marked by grayish fur and a bushy tail. It’s the most common type of fox on the West Coast.

The coyotes that prey upon the fox have become increasingly numerous in San Francisco since 2000, an uptick that Young said has occurred in urban areas nationwide.

Kurtis Alexander is a San Francisco Chronicle staff writer. E-mail: kalexander@sfchronicle.com Twitter: @kurtisalexander