From 260 mph to a Dubuque County Courthouse Ledge
Dubuque County does a wonderful job of providing live views of the peregrine falcons who have made a home on the courthouse ledge. The first egg of the spring was laid earlier this week (April 12), so it's a great time to view. 3-5 eggs are typically laid in a clutch, and both males and females incubate them. Youtube livestreams from multiple angles, photo galleries, and more can be found here: dubuquecountyiowa.gov/385/Courthouse-Falcons.
According to the Iowa DNR, here's what to expect in the coming weeks:
- Incubation time is 31-33 days.
- When hatched, the young peregrines are about the size of baby chickens (2 oz.) and have a light coat of white down. Unlike chickens, peregrines are helpless for the first couple weeks.
- Young peregrines (eyases) can walk when 2 to 3 weeks old and start tearing their own food that the adult brings when about a month old. When they are about 6 weeks old, they begin to fly but still cannot capture their own food. After they have been flying for about a month they start catching prey. When they are 9 to 12 weeks old, they hunt and care for themselves.
- Peregrines tend to be monogamous and maintain long-term pair bonds.
Peregrine falcons remain on the state endangered species list in Iowa, although they were taken off the federal list in 1999. Prior to their populations being decimated by DDT use, peregrines in Iowa nested primarily on rocky bluffs along the Mississippi, and to a lesser extent along tributaries. Prior to reintroduction, the last documented Iowa birds nested in 1956.
Peregrines can fly straight away at 60 mph, and in a dive reach speeds of up to 260 mph. They are very territorial. Normally peregrine nests are upwards of a mile apart. Many peregrines travel great distances during migration. A female hatched in Des Moines in 1994 was captured and released 30 km south of Mexico City, Mexico in March 1995. Peregrines prey primarily on other birds, typically killing 1-2 per day.
For more information on these fascinating birds of prey, visit: iowadnr.gov/peregrine-falcons.