LOS ANGELES -- A conservation group based in Arizona has hired a private investigator to help find those responsible for the shootings of two endangered California condors in the Bay Area in recent weeks.

The Center for Biological Diversity hired private investigator Bruce Robertson of Los Angeles to assist the efforts of the California Department of Fish and Game in investigating the shootings, Adam Keats, director of the center's urban wildlands program, said Friday.

The first incident was reported March 10 when biologists from the Ventana Wildlife Society found an adult male condor, tagged with the identifying #286, suffering from 15 wounds from lead buckshot pellets, according to the California Department of Fish and Game.

On March 26, the unusual incident developed into a pattern after a wounded young female condor, tagged #375, was discovered in the same area in Monterey County. The bird had three shotgun pellets lodged in her wing and thigh.

Both birds are alive, but Keats said it's not clear whether they will ever be able to return to the wild. The condors were part of a flock located near Big Sur, he said, and two of only 85 condors living in the wild in California.

Keats said Thursday that the reward for information about the shootings has also been increased to more than $40,000.

Keats said the increase in the reward is thanks to $8,000 from the Ventana Wildlife Society in Monterey County and $2,500 from the Humane Society of the United States.

The Ventana Wildlife Society had offered an initial reward of $1,000 shortly after the birds were found last month. The Center for Biological Diversity then announced a $30,000 reward earlier this week, with the Wendy P. McCaw Foundation of Santa Barbara pledging $25,000 of that amount and the center providing the rest.

Robertson, who was hired Thursday, said the reward helps people cooperate with investigators.

The investigation "is not unlike solving the shooting of a person or any other crime," Robertson said. "You gather the evidence available, start piecing it together, follow any leads, and if you're working hard and you're lucky, you'll solve the crime."

The Center for Biological Diversity also announced the establishment of a condor investigation hot line: (415) 632-5300. Anyone with information about the shooting also can call the U.S. Fish and Wildlife Service at (916) 414-6660, or the California Department of Fish and Game's CalTIP program at (888) DFG-CALTIP.