- A recently published study in the Journal of Raptor Research links the breeding sites of North American peregrine falcons in Canada and the U.S. to their wintering sites in Peru.
- The farthest-flying peregrine recorded in the study migrated from Alaska to Peru — 10,671 kilometers (6,630 miles).
- Nearly three-fourths of the wintering peregrines captured in coastal Peru were male, supporting the idea that these species practice differential migration, with the larger females wintering closer to their breeding grounds.
- The study was co-authored by the late Oscar Beingolea (1959-2019), a lifelong citizen scientist and renowned Peruvian falconer, known by some as the “the godfather of falcons in Peru.”
When a peregrine falcon crashed through the skylight of a high-rise building in Lima, Peru, what impressed falcon researchers was not its tremendous speed (peregrines are the fastest animal in the world), or that it was found eating a dove in a busy stairwell. But rather, they were impressed by its long, long journey.
A recently published study in the Journal of Raptor Research links the breeding sites of the North American subspecies of peregrine falcons (Falco peregrinus) from their breeding and natal (birth) grounds in Canada and the U.S. to their wintering sites in Peru.
Using 57 years of data from 227 North American peregrines, including eight banded birds, this research adds to what is known about the range of their wintering sites as well as the different migration patterns of male and female peregrines.
Based on the metal band on its leg, placed as part of a U.S. Geological Survey’s Bird Banding Laboratory program, the team knew that the bird found in the stairwell hatched in Canada’s Hudson Bay and traveled 8,870 kilometers (5,511 miles) during its winter migration to the Peruvian capital.
The farthest-flying peregrine recorded in the study had migrated from Alaska to Peru — a distance of 10,671 km (6630 mi)!
“Not until these findings were published was it known that significant numbers of North American Peregrine Falcons winter on the coastal beaches in Peru,” Dan Varland, executive director of the nonprofit Coastal Raptors, who was not involved in the study, told Mongabay in an email.
The study was co-authored by the late Oscar Beingolea (1959-2019), a lifelong citizen scientist and renowned Peruvian falconer, known by some as the “the godfather of falcons in Peru”; and Nico Arcilla, an affiliate fellow at the University of Nebraska and president of the International Bird Conservation Partnership. With Arcilla’s help, Beingolea was able to see his life’s work make it to publication before he passed away in 2019.
Peregrine falcons are fast, in a dive reaching speeds of 320 km/h (200 mph), nearly three times the speed of a cheetah. Their swift, deft hunting skills and sharp appearance have fascinated humans for centuries.
The falcon-headed deity Horus, god of kings and sky, was depicted in ancient Egyptian scriptures 4,000 years ago. In ancient China, raptors were used by humans to hunt as far back as 2200 B.C., and falcons were given as gifts to royalty during the Shang dynasty.
“When the falconer holds a peregrine on his fist, the sense of its power and perfection can be felt in the blink of an eye,” Beingolea wrote in an essay to be published in Spizaetus: Neotropical Raptor Network Newsletter in December 2020.
“Whatever part of the peregrine we see, we have to ask ourselves how a bird could have arrived at such a state of perfection,” Beingolea wrote. “We can consider the selective pressures that have acted on it throughout its evolution, down to the tip of each feather. Still, the forces that have created such a magnificent creature largely defy our comprehension. To try to imagine these, we must leave the falcon on its perch and get out to the field, looking for more.”
Beingolea began studying peregrines in Peru in the mid-1970s, around the time that their populations had hit an all-time low due to the use of the pesticide DDT. This didn’t deter him.
“The difficulty in finding wild birds only whetted my appetite for discovery,” Beingolea wrote. “In particular, mysterious migrants from the far-off northern tundra … Every summer they appeared on the beaches where I grew up … I simply had to learn more about them.”
In response to the peregrine crisis, the species was listed as endangered by the U.S. and Canada in 1970. DDT was banned in the U.S. in 1972. And thousands of captive-bred peregrines were released into the wild, bringing the birds back from the brink of extinction. Peregrines are now listed as ‘Least Concern’ on the IUCN Red List of Threatened Species.
“It shows what people can do when they get together and just decide, you know, we’re going to stop this extinction,” Arcilla told Mongabay.
After the recovery of the species, and following their removal from the endangered species list in 1999, conservation efforts in the U.S. largely ceased. Beingolea’s fieldwork (up until 2019) is one of only a very few monitoring efforts that continued after the delisting, Varland said.
One of the things Beingolea noticed right away in his fieldwork was that nearly three-fourths of the wintering peregrines he captured in coastal Peru were male, supporting the idea that these species practice differential migration, meaning the males and females spend the winter in different locations.
“Imagine if you and your wife or husband spend three months of the year together,” Arcilla said, “and then you say, ‘okay honey, see ya’ … And then both of you just take off.”
North American peregrine falcons are known to migrate in large numbers each year from Canada and the U.S. to spend approximately October through January in Central and South America. However, females typically end up much closer to North America.
Beingolea and Arcilla wondered if these separate winter holidays might be due to the size differences between the sexes. The females are larger, so if a female decides to settle somewhere in Central America for the winter (which is typical) and a male shows up, because he is a lot smaller and she is patrolling the area, she can force him out. He is, after all, competition for food.
Knowing where the birds breed, stop over, and winter is important for understanding their evolution, ecology and how to conserve them, the authors say. This information could help to incorporate reintroduced birds, those from rescue facilities or breeding programs, into natural migration patterns, Stephen B. Lewis a wildlife biologist with the US Fish and Wildlife Service told Mongabay, and could help conservationists decide on an area to focus their efforts, should the need arise.
But fortunately, for now, the number of peregrines remains strong.
“To realize that these birds, which have made such a spectacular comeback, regularly cover such enormous distances was truly stunning,” Beingolea wrote. “It makes you realize how much we still have to discover, even about some of the most celebrated birds in the world.”
“No matter how much research we do on peregrines,” he added, “they remain magnificent enigmas.”
Citation:
Beingolea, O., & Arcilla, N. (2020). Linking peregrine falcons’ (Falco peregrinus) wintering areas in Peru with their North American natal and breeding grounds. Journal of Raptor Research, 54(3), 222-232. doi:10.3356/0892-1016-54.3.222
Banner image of a Peregrine falcon in flight by Miguel Moran.
Liz Kimbrough is a staff writer for Mongabay. Find her on Twitter @lizkimbrough
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