Two Baby Falcons Hatch On Roof Of Evanston Public Library

EVANSTON, IL — A pair of peregrine falcon hatchlings emerged this week from eggs laid on the roof of the Evanston Public Library. Two more eggs laid last month on a column atop the library remain unhatched, as local falcon observers keep a watchful eye on the hatchlings via a live streaming video of the nest.

The first egg of the 2019 season was laid on the afternoon of April 4, and the fourth showed up between the Saturday evening and Sunday morning, according to Deborah Cohen, founder of the Evanston Peregrine Falcon Watch group.

Cohen identified the nest's adults as Squawker, an male hatched in 2003 who has been returning to the library rooftop for a dozen years, and Fay, a 3-year-old unbanded female. The first to hatch cracked the shell sometime on Monday afternoon or evening. The second hatchling was confirmed Tuesday morning.

The incubation period for peregrine falcon eggs is about 32 days, so the other two eggs would be anticipated to hatch in the coming week — if they wind up hatching at all. Falcon-watchers can take a look at the latest happenings on the library roof via the livestreaming EPL Falcon Cam:

The baby falcons, known as eyasses, will spent about 42 days in the nest. During that time, they will grow rapidly, doubling their weight in the first six days after hatching and growing to 10 times their size at birth in the first three weeks, according to Defenders of Wildlife.

This spring marks the 15th consecutive year that falcons have made a home atop the library. Every year that fledglings depart their fourth-floor nest, the library hosts a ceremony to name the new falcons as scientists from the Chicago Peregrine Program at the Field Museum.

In 2017, Fay and Squawker abandoned their rooftop nest — technically called a "scrape" — with their last surviving youngster after one chick died and another egg never hatched. But all four members of the brood survived the following year. At a June 2018 banding event at the library, museum staff announced the four young falcons had been named Ford Falcon, Lightning Bolt, Tango and Karen.

Falcons hold the record for maximum speed while diving, with a top speed of 242 mph recorded in 2005, according to the U.S. Fish and Wildlife Service. In the continental U.S., the subspecies was nearly wiped out in the middle of the last century by the use of the pesticide DDT, which caused females to lay thin eggs that would be crushed during incubation, according to Mary Hennan, director of the Field Museum's Chicago Peregrine Program.

The species was listed as an endangered species in 1970, DDT was banned in 1973 and in 1999 the peregrine falcon was pulled from the national endangered species list. Since then, populations have been slowly rising and urban sightings have become more common. Peregrine falcons were removed from the Illinois Endangered and Threatened Species List in 2015.

Last month, library staff shared an image of a Ford Falcon, who hatched atop the library last year, and was recently seen eating a smaller bird at Montrose Harbor.

These "#falcons get around town! A recent #peregrine sighting at Montrose Harbor was of Ford Falcon who fledged from the library in 2018. (He was eating a Junco. Yum.) Picture by Luis Munoz. pic.twitter.com/IIKXyGR6W4
— Evanston Public Lib. (@evanstonpl) April 3, 2019

Related:

• 4 Fresh Falcons Banded, Given Names At Evanston Public Library
• Library Names Falcon After Deceased Librarian
• Evanston Library's Mother Falcon Takes to Twitter
• Evanston's Peregrine Falcons are Nesting
• Evanston to Name and Band Baby Falcons