The California Department of Fish and Game has joined other groups in trying to find out what's killing brown pelicans along the state coastline. SeaWorld is caring for injured pelicans from San Diego County beaches.
Since mid-January at least 500 brown pelicans have been found along the California coast from San Diego to Crescent City.
The birds have been found in various conditions from merely confused to dead.
Stephanie Costelow is SeaWorld's curator of birds and oversees avian rescue efforts.
She said SeaWorld has taken in 102 brown pelicans since January.
"The birds are coming in primarily a little bit thin, underweight," Costelow said. "Some of them have experienced some form of trauma, beaten -- maybe from storms. We've seen some wing fractures and bruising on their pouches."
She also said some birds have oil or something like oil on their chests.
Costelow said about half of the pelicans brought to SeaWorld haven't survived because many were past a point where survival was possible and in some cases they were already dead.
Costelow said 12 brown pelicans were released Tuesday and more were treated and released last week.
She said about ten avian specialists work to nurse the birds back to health.
Other wildlife-rescue centers in California are also caring for sick and injured pelicans.
While SeaWorld is concentrating on treating the birds, scientists are trying to figure out what's causing the die-off of so many brown pelicans.
Scientists said preliminary research results show many of the insulating properties of the pelicans' feathers have been compromised -- most likely by polluted runoff water.
Many of the rescued birds are suffering from hypothermia.
The California Fish and Game Department is working with SeaWorld, wildlife rescue and rehabilitation groups and the U.S. Fish and Wildlife Service to determine the exact cause of the deaths.
