9 September 2025
Yesterday I mentioned that though many peregrines migrate, Pitt’s peregrines stay here year round. Let’s look at who migrates and who doesn’t with a focus on peregrines in the Americas.
Migratory peregrines
Peregrines eat birds for a living so they have to leave when their food source flies away on migration. In fact peregrines fly with their food because they can catch and eat birds in the air!
North America’s arctic peregrines all leave within a week of the autumnal equinox (22 September this year). In late October 2008 an immature arctic peregrine was passing through Pittsburgh when he got stuck on a balcony. October is when arctic peregrines pass over Pittsburgh, considering when they leave home. Read about his rescue here.
Here are some of the birds he would have eaten on the breeding grounds — American pipit, northern pintail and lapland longspur. These also leave at the autumnal equinox.
The slideshow below dramatically illustrates how quickly arctic peregrines leave on migration. The dark purple blob in Arctic Canada in the week of 20 September is gone by the next week. They are on their way to South America.
Non-migratory peregrines
Peregrine falcons find a lot to eat in North American cities year round. Pigeons are resident and there’s an influx of migratory starlings in winter.
Peregrines are present in eastern North America cities during the shortest days of the year — the week of the winter solstice 20 December. This map indicates they are concentrated at the coast (purple) with a scattering of inland hotspots. The coastal sites include migratory peregrines and wandering immature birds. The inland purple dots are non-migratory peregrines.
Pittsburgh Peregrine Fans, notice how Pittsburgh is a dark purple dot on the map in December. Those are reports of our resident peregrines. Good work, eBirders!
Watch as peregrine abundance ebbs and flows across the globe. Some of the purple blobs in the Southern Hemisphere are fascinating.