San Francisco Bay’s now famous herd of sea lions has mysteriously begun vanishing as quickly and inexplicably as they appeared, leaving behind throngs of disappointed tourists and puzzled marine biologists, according to a recent Associated Press report.

A mere month ago, a record 1,500 of the massive marine hunters were making their abode on the Bay City’s famous Pier 39. Yet just days after the Thanksgiving holiday, the bustling troop of 800-pound behemoths began leaving en masse.

Marine experts in the region speculate that the sea lions came in droves because of an abundance of food and that they probably disappeared when the food started running out or going elsewhere.

“Most likely, they left chasing a food source,” Jeff Boehm, executive director of the Marine Mammal Center in Sausalito, explained to the Associated Press.

“It’s probably what kept them here in the first place.”

The Marine Mammal Center also has a gift shop and info center for tourists at Pier 39, and given the boom in business that they had experienced since the arrival of the sea lions, they’ll likely be missing the creatures more than the crowds of cooing tourists will.

Boehm told AP that the only thing stranger than the abrupt disappearance of the animals is that they stayed so long in the first place.

According to Boehm, it’s typical for adult sea lions in the area to go south to the Channel Islands along the Santa Barbara Channel during the breeding season. Uninterested in breeding, however, the footloose and fancy free young sea lions will often spend the season traveling up and down the coast without an apparent aim or direction.

“[Younger sea lions] don’t mind the rules and tend to travel far and wide,” explained Boehm.

With the vast majority of the herd having already set off in search of sardines and anchovies, a mere 10 sea lions remained on the docks on Tuesday, frolicking and sprawling themselves out where just a month ago they had been packed like…well, sardines.

But the small remnant of vivacious juvenile animals was enough to impress a surprisingly large crowd of visitors that had braved the biting coastal winds to catch a glimpse of the marine mammals.

Tourists were delighted just to catch a glimpse of the diving, honking, barking clan of young pups.

“We’re happy with what we see,” said one visiting Floridian couple who happened to be in the throng of observers to the Associated Press.

Boehm and his colleagues say they are not terribly concerned about the sea lions’ rather abrupt vanishing act. As usual, he said, the herd will more than likely make its grand return in spring.