Biologists mystified by seabird die-off on West Coast
CBC Radio | Posted: January 6, 2015 5:00 AM | Last Updated: January 6, 2015
So far this winter, thousands of dead Cassin's auklets, Robin-sized seabirds, have washed up on the Pacific coast between San Francisco and Haida Gwaii. It's more than ten times what is the norm, and bird exprets are struggling to figure out why.
People have been out collecting the birds' remains, most of which were only born last summer, biologist Julia Parrish tells As It Happens host Carol Off.
"We're easily seeing tens of thousands, if not more than that," she says.
The scientists' best guess about the cause of the die-off is that they are victims of their own success: the birds had a very successful breeding season last summer, and there are many more young birds competing for food.
The auklets have been tested for disease or poisoning, and nothing's been found, says Professor Parrish. "They simply starved to death"
She adds that it's also unusual for the birds to be so close to the shore, as they usually live many kilometres out to sea. This, and that it seems to be affecting only Cassin's auklets and not other birds, only adds to the mystery, she says. "We're not really seeing an uptick in (deaths of) other seabird species."