It's been relatively quiet at San Francisco's Pier 39 over the past few weeks. The hundreds of sea lions that normally populate the docks at one of the City's most popular tourist attractions have been scarce, leaving many to wonder where they went.
Now scientists think they've figured out what drove the droves of smelly inhabitants of Fisherman's Wharf to leave: their appetites.
The herring-munching mammals have likely gone in search of their favorite food -- which hasn't shown up in San Francisco Bay as in recent years.
The blubbery ones have headed south toward to Monterey Bay for a food vacation, according to the Marine Mammal Center in Sausalito, which has tagged some of the animals and tracked them there. An NBCBayArea.com reader also reported spotting some at Moss Landing.
According to other reports from audience members, a few have stuck closer to home, at San Francisco's Hyde Street Pier and the Seal Rocks.
Biologists say the mass disappearance of the raft-resting sea lions from Pier 39 is a bit unusual -- but spotting them elsewhere isn't so out of the ordinary.
"They've probably not left the area entirely," said Ann Bauer of the Marine Mammal Center. "People are still seeing them here and there, but the greater mass of them is probably out somewhere in the ocean."
Biologists expect the loud Bay Area attraction to be back in San Francisco by the spring.