It is the peak of the peregrine falcon migration along the coastline of South Padre Island, and biologists with the Peregrine Fund and Earthspan are busy capturing, banding and taking blood samples form these magnificent birds of prey.
Bill Heinrich, Restoration Director for the Peregrine Fund, says, "Well we are looking for peregrine falcons. We are trying to trap as many as we can this season to take blood samples. And the reason we are doing that is to try and find if there are any contaminants related to the oil spill."
The biologists will compare blood samples from birds captured on South Padre in years past with those from current migrants. A similar study is underway on the east coast.
Just as declining numbers of peregrine falcons alerted the world to the dangers of the pesticide DDT more than 30 years ago, the falcons are once again serving as an important sentinel species.
Gregg Doney, Research Associate with Earthspan, says, "We are applying our background knowledge of the peregrine and utilizing it as a sentinel species to see if any of these oil spill related contaminants are cycling thru the food chain."
Perched atop the food chain, the peregrine falcon during its migration along the Gulf will accumulate toxins in ever-larger quantities if they are present in the environment as they feed on birds sickened or weakened by exposure to the spill.
Biologists hope to capture, sample and release more than 100 birds on Padre Island this month, and the study is expected to continue for several years.