The Thoughts of an Ornithologist
William Princeton
(1) I’ve spotted a young female Peregrine Falcon, but cannot read the two-digit code on her vid band. Because the Peregrine travel up to 15,000 miles each year, these colored leg bands are essential to identifying and tracking the birds. This bird has fantastic markings—through my binoculars, I can clearly make out the black mustache mark common to this species. I calculate the bird’s speed to be twenty-five miles per hour—she merely coasts while monitoring the mountainside for a tasty meal. Once the predator has focused in on her prey, she dramatically descends into that spectacular hunting stoop. At this moment, she’s the fastest animal on the planet—scientists have clocked Peregrines at speeds of 200 miles per hour during this hunting dive. I’m on cloud nine as I silently observe the bird’s victory.
(2) As a child, I was obsessed with the study of birds, known as ornithology. I spent every opportunity observing the birds that lived around my family’s home. Ornithology drew me in like a moth to a flame. After completing high school, I was accepted at the Cornell Lab of Ornithology where I became involved in species conservation. I spent several years color banding a wide variety of birds in California with the Fish and Wildlife Service. The banding systems allowed us to study the birds’ annual survivorship, fidelity to territory and mate, and migratory status. Years later, an acquaintance of mine from Cornell offered me a position on a team that works for the conservation of Peregrine Falcons. I’ve been fascinated by these birds ever since.
(3) The Peregrine population crashed between 1950 and 1970 due to pesticides like DDT. The future of these magnificent birds remained uncertain for nearly two decades. Thanks to the diligent work of conservationists like Tom Cade, officials removed the Peregrine from the endangered species list in 1999.
(4) Of course, these birds still aren’t entirely self-sufficient. The major concern is that the falcons tend to nest in urban areas because of a phenomenon called “imprinting.” Falcons often reside in habitats similar to their natal nests, or the nests where they were born. For birds bred in captivity, the site of their release is often imprinted in their brains. Early recovery efforts used skyscrapers in urban areas as release sites for the Peregrine, causing the birds to return to large cities later in life.
(5) Our program has chosen to get back to nature by releasing the birds along the rock faces of the Mississippi River Valley. We are optimistic that the difference in the imprinting will encourage more falcons to nest in the wilderness. Fledgling falcons are raised in cliff-like nests constructed of real and fabricated rock, with no man-made structures in sight. When we release the birds from the bluffs of Effigy Mounds National Park, they recognize the craggy cliffs as their home.
(6) Back along the cliff side, after some careful scrutiny, I’ve identified the female falcon as B/6. She has returned to her cliff nest with her prey held tightly in her talons. There appear to be young in the nest—a successful natural mating here on the rock face! This is what makes all our hard work worthwhile. The Peregrine Falcons are staging a real comeback!
Question
The result was that the Peregrine population crashed between 1950 and 1970. What was the cause?
Think about cause-and-effect relationships.
Responses
A diseasedisease
B huntershunters
C mutationmutation
D pesticidespesticides