High-diving seabirds known as blue-footed boobies have suddenly expanded their range in California.
The birds are rarely found north of the Salton Sea, but in recent weeks have been found across Southern California and as far north as Marin County in the San Francisco Bay area.
Kimball Garrett of the Natural History Museum of Los Angeles County tells the Los Angeles Times that the birds are suddenly “all over the place.”
The species is large, bluish-gray, with a long, serrated beak, short legs and bright blue webbed feet.
Rare sightings of dancing, blue-footed birds are being recorded along the Point Reyes Peninsula and other areas of the county’s coast.
The arrival of the blue-footed booby along Marin’s coast is part of an invasion of the species into the state as the birds stray far from their normal roaming grounds from the Galapagos Islands to the Salton Sea.
Birder and Marin Audubon member Len Blumin of Mill Valley saw one of the birds Thursday afternoon at Chimney Rock.
“It is a striking bird,” Blumin said. “We were lucky to have seen it.”
There was a report of one off of Rodeo Beach recently and of two at the Point Reyes Lighthouse Thursday morning. Point Blue Conservation Science researchers on the Farallon Islands also reported a sighting of the species Thursday morning.
The blue-footed booby is known for its long, pointed beak, clumsy waddle and unique seafoam-blue webbed feet — a combination that makes the bird look like it walked off a Pixar movie set.
And don’t forget its one-foot-up, one-foot-down mating dance performed by the male of the species.
The booby seen Thursday was perched on a rock for about an hour, and Blumin was able to see the last 10 minutes of the display.
“There must have been about 10 of us there and we all got to see it before it flew off,” he said. It was the first time Blumin has seen the species in Marin in two decades of birding. “This was a juvenile, which normally don’t have the bright coloring, but this one did around its face.”
The sightings in Marin and in other parts of the state have caused a stir in the birding world.
“Huge excitement for birders,” said Brian Sullivan, a locally based director of eBird.org, a project of the New York-based Cornell Lab of Ornithology, where one of the Point Reyes sightings is officially noted. “Right now there’s lots of birders out there to see and document this invasion.”
The last time this number of the species was seen in the state was 1971. Experts believe the boobies are being pushed up the California coast because of a collapse of their food supply in Mexico. The combination of food scarcity following robust breeding seasons may explain why this event, as in 1971, features mostly juvenile birds.
“The blue-footed booby are really set up to take advantage of good years,” said Bernie Tershy, a UC Santa Cruz professor who wrote his dissertation on the boobies.
He noted that while other kind of boobies will hatch one chick, the blue-footed variety can hatch up to four.
“Their population can increase dramatically during good years,” he said.