Right now, hundreds of thousands of birds are migrating south, through the Florida Keys. So far our team has rescued, rehabilitated, and released a handful of migratory birds of prey, including a Cooper’s Hawk (Accipiter cooperii) that is currently being treated in our hospital for head trauma. One of the most iconic species of the migrating raptors that we see in the Florida Keys is the Peregrine Falcon (Falco peregrinus). In fact, their name is quite literally from Latin as “the wanderer,” making them the “wandering falcons.” (v) Why are they so iconic? This week we’d like to make another entry in our Bird Spotlight series, and we’ll focus on the facts that make these falcons so popular among birders.
Today, peregrine falcon populations are considered to be “least concern” by the International Union for Conservation of Nature and Natural Resources (IUCN), but there was a period of time when their numbers were dangerously low. (i) In the early and mid-20th century, many species of raptors were almost driven to extinction due to the use of dichlorodiphenyltrichloroethane (DDT) and other pesticides. (iii) DDT caused thinning of the shells of bird eggs in many bird species, including osprey and peregrine falcons. (iv) After an egg’s shell has been thinned it can break much easier and the egg can suffer from embryo death, and this led to a much lower reproductive success in many bird species. DDT would eventually be banned by the Environmental Protection Agency (EPA) in 1972. This lead to a return to stability for falcons and many other species of birds that were negatively impacted by DDT. It’s estimated that there could be as many as 500,000 mature peregrines living in the wild. (i) That’s a major resurgence for the species, and it’s a testament to the efforts that are being put forth to better protect these aerial predators.
Peregrines hunt mostly for other birds, including doves (their favorite meal), ducks and shorebirds. (iii) To accomplish this, peregrines use a method of hunting referred to as “stooping.” Stooping birds soar high above potential prey items, and then dive downward through the air, eventually grasping their prey with their talons and taking it to the ground for consumption. While diving downward towards it’s prey, a peregrine can reach speeds of over 200 miles per hour, making it one of the fastest moving animals on the planet! (iii) When they are pursuing prey directly, peregrines can reach speeds of almost 70 miles per hours. (ii)
In terms of their habitat range, peregrines can be found all over the world, including all continents except for Antarctica. They can also be found on many small, coastal islands. (ii) In North America, they generally inhabit the Midwest and Pacific coast all year, and populations will migrate from Western Canada and Alaska to South America and the Caribbean during the fall migration. (ii) Along the way, these falcons follow the migration routes of water fowl and other prey that they hunt. During migration, an individual peregrine can log as much as 15,000 miles during it’s round-trip journey. (v)
Do you want to get involved with citizen science and help to count peregrine falcons during migration? There’s good news, because you can! One of the best developed citizen science programs in the Florida Keys is the Florida Keys Hawkwatch program at Curry Hammock State Park. Birders of all skill levels and ages are able to work alongside expert Hawkwatch veterans while counting south-bound raptors. Last year the Hawkwatch team counted 19,229 raptors during migration, including 4,559 peregrine falcons (a new seasonal record)! For more information about the Hawkwatch program, and to learn about how you can volunteer and help their team, visit their website by clicking here.
Ian Martin, Education Coordinator, 2016
(i) IUCN Red List: Peregrine Falcon
(ii) All About Birds: Peregrine Falcon
(iii) Audubon Society, Guide to North American Birds: Peregrine Falcon
(iv) Agency for Toxic Substances & Disease Registry: Toxicological Profile for DDT, DDE, and DDD
(v) National Geographic: Peregrine Falcon