SAN MARCOS, Calif. — Amber Lindsey lives on Lake San Marcos. She and other residents care for the beautiful and exotic bird population, including the black swans the area is famous for. But last month, after a pesticide was sprayed around parts of the lake, several birds got sick.

“After the first spray, which was about September 14, we noticed erratic behavior,” Amber said. “More neurological and symptoms of twitching ‘over-preening’ and left a sheen on the birds.”

They notified their HOA, but the spraying continued two weeks later on October 3.

“After that spray, we noticed very quick deaths,” she continued. “Within two or three days, severe symptoms taking two or three days to actually pass.”

About this time, the highly contagious Avian bird flu made its appearance in Orange and Los Angeles Counties.

Concerned that the pesticide is not only killing the birds but the runoff is poisoning their lake, they sent a bird carcass to UC Davis in San Bernadino for testing.

But here’s where things went wrong. They say the pesticide company took too long to provide them with a list of chemicals.

“It took us a number of days to receive the chemical breakdown that was used in order for us to do an effective autopsy,” Amber said. “By the time that breakdown was given to us, it was too late and the bird had been destroyed.”

They say they were told the bird was destroyed because it has Avian flu. Meanwhile, 15 more birds have turned up dead on the lake.

“The one thing we want to make sure, that these birds are not conveniently destroyed because nobody wants to know whether this pesticide application, which were saying we have a legitimate observation and information on, it’s not part of what attributed to these deaths,” she said.

Again, according to the Humane Society, there’s one confirmed case of Avian bird flu in the county.

We did reach out to CDFW who would oversee the autopsy of the dead birds. They say their protocol if they detected bird flu, it would be destroyed and then they would continue their research to identify cause of death. But they say they did not perform the autopsy on the bird from San Diego.