This time each year, hundreds of croaking, roaring, shrieking elephant seals gather to breed and give birth on the rocky shoreline below Hearst Castle.
The boisterous annual show draws hordes of tourists to a boardwalk 15 feet above, where they can watch the enormous pinnipeds tend the shiny black pups, squabble over beach space and battle for the right to mate.
But this year, the traffic jams near the Piedras Blancas birthing grounds aren't being caused just by curious motorists.
Some of the seals are sneaking past barbed-wire fences designed to protect them, then flopping on blubbery bellies right across California 1.
Their dangerous behavior has police and seal-lovers worried.
"When a 4,700-pound pickup truck meets a 5,000-pound seal, they both lose," said Ken Cumings, a docent with Friends of the Elephant Seal who has watched the events unfold.
In recent weeks, at least four of the animals have attempted great escapes.
In December, a motorist struck and killed one of the federally protected mammals. Then a female seal crossed the fence line for a few hours before being herded back to the beach.
A few days later, a male seal, nicknamed Lucky, got to the other side of the road by way of a culvert and took up residence for 10 days on the Hearst Ranch property.
It took a team of biologists, rangers and police in four-wheel-drive trucks to finally coax Lucky back to his mates across the two-lane highway. Last week, another seal was reported on the Hearst Ranch property, but the animal appeared to make it back to the beach on its own.
The encounters have left local officials scratching their heads over how to keep the highway safe while protecting the thousands of seals that return to Piedras Blancas each winter.
The phenomenon of wandering seals isn't entirely new. Seals and motorists have had encounters before. Seals have been killed and drivers injured.
But Brian Hatfield, a biologist with the U.S. Geological Survey who has watched the rookery grow from a few seals in 1990 to an estimated 16,000 this year, said it had become more of a problem as the population exploded.
"This year seems to be particularly bad," Hatfield said. "I'm not sure if it's overcrowding or if the barriers have just eroded."
The Piedras Blancas birthing ground is one of an estimated 17 rookeries dotting the Pacific coast and offshore islands from the Gulf of Alaska to Baja, Mexico.
Piedras Blancas is one of the newest -- and the only one next to a major highway.
Tourists who visit get an unparalleled look at the social animals, and mating season is when they are at their antic best, docents say.
Big bull seals, alpha males with distinct, long elephantine noses, battle for the right to dominate large harems. Quarrels over where one harem ends and another begins break out with regularity, sometimes resulting in bloody fights. Females, meanwhile, squabble over prime beach space while slick black newborn pups screech for attention.
"It's a soap opera every day," said James Ensworth, who for the last two years has put in three-hour, twice-weekly shifts as a docent. "It never gets old."
Dominant male seals begin to arrive and spar in December. An older alpha male can claim up to 50 female seals for himself, chasing off any competitors who try to get close.
Females arrive through mid-January, pregnant and ready to give birth. Each carries a single pup. On a recent visit, hundreds of females, with their black-haired pups close by, crowded nearly side by side -- so many that from 200 yards away the beach looked as if it were covered in cobblestones.
The newborn pups shriek as they frantically bump against their mothers' bellies in search of milk.
Squawking gulls, meanwhile, announce the births by racing to grab the protein-rich placenta. Paying close attention are the 2-ton, battle-scarred "harem masters," who can rise with surprising speed and grace to chase juvenile males back into the ocean. They throw back their leathery heads to croak out warnings to would-be Lotharios.
The females devote the first month of their pups' lives to nursing. During that time, the 60-pound newborn seals' weight quadruples.
After their pups are weaned, females mate toward the end of February and then return to the ocean.
In the early days of the Piedras Blancas rookery, no fencing separated the beach from the road, Hatfield said. The male seals, which can travel up to 25 mph and go for months without food, occasionally would be struck by cars.
About 10 years ago, the California Department of Transportation realigned California 1 near the rookery and installed a large public parking lot and viewing area for motorists. It also put up barbed-wire fencing in an attempt to reduce accidents.
That seemed to have worked fairly well until this year, Hatfield said. But blowing sand builds up along the fence line, making it easier for seals to slip over the top. After escaping through storm culverts under the highway, some of the animals can't find their way back, officials believe.
Why they leave the beach is anyone's guess. It could be overcrowding. Or juvenile males may take off after being forced out of harems, biologists said.
"Some of them get chased out by the bigger guys who want to give them a thumping," Hatfield said.
Caltrans is planning to repair fences and place grates over the culverts to minimize the possibility of future escapes, said spokesman Jim Shivers.
Workers also are scheduled to clear sand that has built up so high in places that it is nearly level with the top of the 4-foot-high fences. But work can't begin for at least two months, after breeding season winds down, Shivers said.
"We suspended work a few weeks ago," he said. "We don't want to do anything that would bring harm to these animals or that would violate the Marine Mammals Act."
Until then, local officials are keeping their fingers crossed.
"I'm just waiting for some poor German tourist to round a curve and come face to face with an elephant seal," said Rob Bryn, spokesman for the San Luis Obispo County Sheriff's Department.
"That wouldn't be pretty."