Updated: 29 November 2011
Wildlife officials are trying to determine the cause of death of a killer whale that washed ashore on a Point Reyes beach.
"It's pretty rare to see an orca washed up on shore around here," said Jim Oswald, spokesman for the Marine Mammal Center in the Marin Headlands, which is investigating the death along with the California Academy of Sciences in San Francisco.
The orca was a male juvenile, about 18 feet long, that had washed up in an isolated area along Driftwood Beach, just north of McClure's Beach, late last week.
The team from the mammal center and academy went to the site Saturday and removed the orca's head and dorsal fin and took samples of its skin for study to determine a cause of death.
"The cause of death is still undetermined," said Andrew Ng, spokesman for the academy. "There were possible signs of trauma."
Whether that trauma was caused by another mammal or a ship strike was still to be determined, officials said. Tides were expected to carry the orca's carcass back out to sea.
The black-and-white mammals, which can grow up to 30 feet long and weigh as much as 12,000 pounds, are the largest species of the dolphin family and considered highly social and intelligent creatures.
They can live to age 50 and older, and travel in pods in which they are often related to one another. Killer whales prey on fish, but occasionally attack sharks, gray whales, seals, sea lions and blue whales.
"In the last five or six years we have seen orcas off the (Marin) Headlands," said John Dell'Osso, a spokesman for the Point Reyes National Seashore. "They may be following prey that are coming here."
Gray whales are now migrating from Alaska down to Mexico. It's possible the dead orca was making the same migration, he said.
"I do not ever remember an orca washing up on shore out here," said Dell'Osso, who has worked at the seashore for 27 years.