Peregrine Falcon Recovery Program

Though not the only reason for the peregrine falcon's decline, the pesticide DDT had passed through the food chain and weakened the shells of peregrine eggs, leading to the loss of many young before they could hatch.

The curtailment of chemical pesticides and the success of nest boxes like Thermal’s have led to an impressive recovery of the peregrine falcon population.

MRMC Thermal’s peregrine falcon nesting box is part of a state-wide falcon recovery program managed by biologist Greg Septon.

Read the Wisconsin Falconwatch – 2024 Nesting Season Report (PDF)  (see page 17 for our nest) to learn more about Wisconsin peregrine falcon nesting activity and the young that were produced.  

 

Recent News  

6/26/25:
Caught Hayden at the nest today.  Note the feet are not yellow yet.  58 AC


6/20/25:
Rossi and Hayden have both flown the nest.
Mom looking for flyers.  
Check out the video below for flight transfer of food training.



6/13/25:
Rossi has flown the nest!  Hayden remains, but looks sad.  

From Greg Septon:
Yes, it looks like “Rossi” (b/blu) 59/AC has left the nest box. When we banded your young the sex of Rossi was in question but the fact it fledged first indicates its like a larger male.

Here’s what to expect as we look at the next week or so:

Everything should go just fine but every once in a while a newly fledged youngster gets grounded during their first week or so on the wing. IF this happens the first thing you want to do is make sure it’s not injured, i.e. a drooping wing or a limp, or signs of blood, ect. If the youngster doesn’t appear injured, the best thing to do is just throw a towel (like a bath towel) over it, gather it up and release it back up on the roof. You don’t need to get it back to the nest box - just let it go on the roof outside the access door of the lower roof. The adults will see it and from that point just let nature take its course. In nearly every case where a youngster gets grounded on their first flight, all they ever really need is a good second chance.

6/10/25:  
Practice, practice.  Feet are turning yellow...maturing.


6/9/25:
Energy levels are high in the nest....getting ready to fly...learning about food transfers...here's a video that explains that piece of learning.




6/5/25:
Awaiting breakfast...Peregrines first fly 35 to 45 days after hatching (hatching was May 8th this year), when they have reached adult size. They begin to hunt around 60 to 80 days.



6/5/25:
Made it to the green ledge!


6/4/25:
A lot of flapping going on...the female chick almost made it to the green ledge today.  The smaller chick grabbed food from mom today also.  The larger chick and mom looked at each other and the mom just flew away.  Brought back another meal, but then took off with it right away.  Interesting.  Last photo: smaller chick wondering what the female is DOING....all that flapping.



ALMOST!  



5/28/25:  
Amazing how fast they grow!
The two females were named Hayden and Rossi after motorcycle racing champions because they can reach speeds over 200 mph just like the world class racers.
The birds were not harmed during the banding process.


5/8/25:
Two hatchlings so far...two eggs left (that were laid a while from the others).
One egg was kicked to the side yesterday, but is back in the fold.


5/3/25:
Hatching has begun!


5/2/25: 
Nesting sharing switches.


4/25/25:
Still waiting...getting closer!  

4/4/25:
Mama on the nest.  Mugs is the banded male.  The unbanded female is likely from past years.


4/1/25:

4 eggs!  No foolin'!  Should hatch beginning of May.


3/25/25:
First egg of the season!  



2/25/25:
Activity in the nest box!



3/11/25:
A pair has been seen in the nest box.





About the Peregrine
Life Cycle

Prey

Peregrines take their prey in flight, so they dine almost exclusively on other birds. However, very young falcons may catch flying insects and, occasionally, Arctic peregrines will catch and eat ground-dwelling animals like lemmings.

Male peregrines, which are substantially smaller, will generally catch smaller birds, but females will take larger prey like ducks. Peregrines can eat as much as one-quarter of their weight at one sitting.

Reproduction

Peregrines usually begin breeding at about 2 years of age. The male will put on an aerial courtship display to attract a mate to a selection of nesting sites. The female chooses. Peregrines generally mate for life, returning each year to the same area and even the same nest. However, the female will accept a new mate if the first is killed.

There’s nothing fancy about the nests. The nest, "scrape," is traditionally no more than a depression in a cliff ledge. But nowadays, possibly in response to increased human contact during captive breeding projects, many peregrines find homes in man-made structures and more populated areas, using power plant smokestacks, steeples, tall buildings and bridges.

Females lay a clutch of 3 to 5 eggs in the spring. The eggs range in color from pink to brownish and are about 2 inches long. It takes about a month before the eggs hatch. Newly hatched peregrines, weighing in at about 1.5 ounces, double their weight in just six days and and increase tenfold by three weeks. Hatchlings are covered with fluffy white down, replaced by feathers in 21 to 35 days. Peregrines first fly 35 to 45 days after hatching, when they have reached adult size. They begin to hunt around 60 to 80 days.

The mortality rate is very high for young peregrines. Only one in 10 makes it to breeding age. They can live for up to 15 years.

Range / Migration

Peregrines are found all over the world except in Antarctica and the Pacific Islands. The most common subspecies in the United States, falco peregrinus anatum, is found from central Alaska to central Mexico and usually winters in South America. A maritime subspecies, Peale’s peregrine, found in the Northwestern U.S. and north, does not migrate.

Generally, the birds head south in September and may spend a month to reach their winter homes in Central and South America. Arctic peregrines have been seen as far south as Argentina. Some urban peregrines do not migrate anymore, since their prey – pigeons and starlings – remain abundant year round.

Nesting Box Webcam

Through the box’s webcam, you can watch for the falcons to return, eggs to be laid and hatched and activity in the nesting box as the chicks grow during nesting season (March through July).