Category: Blog


Published: June 5, 2015

Peregrine Removed from Illinois' Endangered List

Mary Hennen, Assistant Collections Manager, Birds; Director, Chicago Peregrine Program, Gantz Family Collections Center


Illinois officially removed Peregrine Falcons from the state Endangered & Threatened Species List.

What does this means for our state population of Peregrine Falcons? First, it is an affirmation of the recovery of the species in Illinois.  This is due in part to the long-term stewardship and dedicated effort of numerous individuals and organizations that have supported and assisted in looking after Illinois’ Peregrines. 

It does not leave our Peregrines unprotected. The Migratory Bird Treaty Act makes it "illegal for anyone to take, possess, import, export, transport, sell, purchase, barter, or offer for sale, purchase, or barter, any migratory bird, or the parts, nests, or eggs of such a bird except under the terms of a valid permit issued pursuant to Federal regulations." Peregrines are protected under this law. 

Another thing the Peregrine’s removal from Illinois’ state Endangered & Threatened Species List will not change is the work conducted by the Chicago Peregrine Program. The Chicago Peregrine Program oversees Illinois' Peregrine Falcon population. This is accomplished in part by monitoring individual birds as well as nest sites, conducting scientific research and participating in public education.

Illinois currently (2015) has Peregrines at 28 different locations in the state, 19 of which are breeding pairs. While the majority of the state population are urban dwellers, Peregrines are using natural cliffs down near Alton, IL.

It has been wonderful to witness the return of Peregrines to Illinois. Many thanks and congratulations to all! 

Mary Hennen
Assistant Collections Manager, Birds; Director, Chicago Peregrine Program, Gantz Family Collections Center

I have been working in the Bird Collection in some capacity (at times student, volunteer, or staff), since 1989. Much of my time is spent with skeletal prep including managing the Bird's Dermestid colonies.

My primary work outside of the bird collection is with Peregrine Falcons (Falco peregrinus). As recently as 1960's, Peregrines had been extirpated east of the Rockies.

Many factors contributed to the decline of Peregrines, including habitat loss, hunting, and egg collecting, though the predominant cause was effects of organochlorines such as DDT. By comparing the egg shell thickness of the few remaining peregrines to historic oology collections including the Field Museum's, scientists discovered that DDT and it's byproducts interfered with calcium production in females causing them to lay thin eggs which subsequently were crushed during incubation.

With the recovery of the species, the Chicago Peregrine Program now directs it's focus towards monitoring Peregrines in Illinois. The Peregrine Falcon was removed from the Federal Endangered Species List in 2000 and has been approved for removal from the Illinois State Endangered and Threatened Species List in 2015.