REED POINT, Mont. -

Researchers are using blood samples from osprey to determine whether pollutants from industrial sources are contaminating the birds' food supply along Montana's Yellowstone River.

The three-year-study of the fish-eating birds of prey is being conducted through the Yellowstone River Research Center at Rocky Mountain College.

Rocky associate professor Kayhan Ostovar said Monday that the project will allow scientists to compare the health of the Yellowstone to other rivers across the country.

Researchers so far have collected blood samples from osprey in 63 locations. Ostovar says that data will be analyzed in coming months.

More than 50 percent of osprey chicks do not survive. In recent weeks, hail storms in southern Montana killed at least two chicks. Another was killed by a golden eagle.