Lost California whales ignore "go home" siren song

SAN FRANCISCO (Reuters) - Two wounded humpback whales that swam 92 miles up rivers and a man-made canal into California's Central Valley are not responding to recorded whale calls aimed at luring them back to sea, scientists said on Thursday.

The roughly 45-foot (13.7-metre) female and her 20-foot (6-metre) calf had swum to California's Port of Sacramento and meandered in the same area on Thursday as rescue officials played recorded sounds from a boat aimed at luring them downstream.

"From what we have seen I don't think it is very successful," said Carrie Wilson, a marine biologist with the California Department of Fish and Game. "It appears that the animals are not responding."

Both whales were injured by boats during their journey upstream.

The tale of the lost whales is attracting a growing number of visitors to the area near the California state capital and memories of a humpback whale dubbed Humphrey that swam up the Sacramento River 69 miles in 1985 before returning to the ocean in a 26-day saga.

Experts say the current incident is the longest recorded inland U.S. journey for humpback whales.

The scientists have been playing sounds of whales feedings rather than love songs. "Because she is with a tending calf we don't think she would be interested in any breeding-related calls at this point," said Joe Cordaro, a wildlife biologist at the National Marine Fishery Service.

Scientists said they are likely next to try a new approach of blasting noise from boats on the upstream side in an effort to inspire them to move in the other direction.

Cordaro said scientists were improvising as they sought a solution and would consider anything to get the whales moving toward the ocean.

"Maybe even Barry Manilow music, it worked in Panama," he joked, referring to the blasting of the pop singer's music toward the country's dictator who had taken refuge in an embassy. "Nothing's off the table at this point."

The whales are believed to belong to a group of humpbacks which migrated from Baja California, Mexico, to spend the summer near the Farallon Islands off the coast of California.