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.

Three baby falconsThe 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 – 2020 Nesting Season Report (PDF)  (see page 15 for our nest) to learn more about Wisconsin peregrine falcon nesting activity and the young that were produced.  

Recent News  

May 24, 2021

Banding:  Trident (f), Polaris (f), Posiedon (m).  Fledging in 2-3 weeks.

May 19, 2021

Growing and sitting up ... 

May 13, 2021
4th Hatched but didn't make it.
Donald shown feeding in first picture.  Female in second picture.

  • 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.

    More on hatchling development:


May 6, 2021
Third has hatched!

May 5, 2021
Second hatchling!

May 4, 2021
First of 4 eggs hatched!
April 1, 2021
3rd Egg - Estimated hatching:  May 4-6


March 30, 2021
Egg #2!  


March 25, 2021
First 2021 Egg at the Thermal Plant!

March 8, 2021

The falcon pair have returned!  The unbanded female (likely the same as last year) and the same adult male "Donald" have been identified in our nest box.  Donald is up to his same old tricks and is courting two females again - at our Thermal box and the female that travels between the Miller and Malteurop sites.  

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). Note that the webcam image below is not a streaming image but does refresh every 60 seconds; refresh your browser window to capture ongoing views.

Viewer discretion is advised.
Due to the sometimes-violent nature of birds of prey, some webcam content may be difficult to watch. Please be aware webcam content is not monitored or screened.