“It’s a girl!” Mary Hennen, head of the Peregrine Project at the Field Museum, holds the female peregrine falcon chick, Hennen, named after her.

Getting your Evanston news from Facebook? Try the Evanston RoundTable’s free daily and weekend email newsletters – sign up now!

The three peregrine falcon chicks that have been residing on the roof of the north side of the Evanston Public Library were banded and named May 26 at 11 a.m. while the chicks’ parents, Nona and Squawker, flew up and down Church Street in front of the library in protest.

A crowd of onlookers watched as Mary Hennen, head of the Peregrine Project at the Field Museum, and Matthew Gies, a supervisor at the Shedd Aquarium, climbed up a ladder to reach the nest, braving the anger of the parents to get the chicks. Chicks in hand, Ms. Hennen, Mr. Gies and his wife, veterinarian Barbara Royal, determined the sex of each chick, took blood, and banded them.

Paul Gottschalk, administrative services manager of the library, called out the names of the chicks after their sex was determined. The names, which in the past have been also based on literary figures relating to falcons, were all honorary this year. The first chick, a female, was named Lorraine after former Mayor Lorraine Morton. The second, another female, was named Hennen in honor of Ms. Hennen. The only male was named Perkins after celebrated Cook County architect Dwight Perkins.

Mr. Gottschalk declared the event a success, commenting that there seemed to be a larger audience than in previous years.

While the falcons’ popularity has grown, this is the fifth year that Squawker and Nona have chosen to nest on the third-floor ledge of the City’s main library and the seventh year in a row that peregrine falcons have nested somewhere on the library. Since spring of 2004 these birds, the world’s fastest creatures – able to fly about 200 miles per hour – have chosen the library’s wide ledges, columns and windowsills as a nesting ground. Former Evanston Public Library director and birdwatcher Neal Ney said he believed the annual appearance of the birds could be attributed to the building’s architecture, which resembles features of the bird’s normal nesting ground.

“We have artificial cliffs, essentially,” Mr. Ney said.

He added that in 2004, when the first set of peregrine falcons nested on the library, the mother broke her wing and was unable to help the chicks’ father gather food. Using quail that representatives from the Field Museum provided for him, Mr. Ney said he would climb on the library windowsill to feed the birds. Peregrine falcons eat medium-sized birds such as quail, and City-dwelling peregrine falcons are known to eat pigeons, commonly leaving behind the wings and heads of their prey, said Ms. Royal.

“Unfortunately there has been no significant effect on the pigeon population,” said Mr. Gottschalk.

In any case, the presence of the falcons seems to have brought the Evanston community together. While Mr. Gottschalk said he did not believe the presence of the falcons increased community use of library services, he said there has been a lot of interest in the birds for the past several years. To date, more than 20 peregrine falcon eggs have successfully hatched in various places around the library. Interest in the birds led to the 2005 installment of the Falcon Cam, which takes pictures of the current nest every few minutes and posts them on the library’s website.

Lesley Williams, head of information services at the library, said she was happy to have the falcons reside at the library.

“It’s brought such enthusiasm and excitement to the library,” said Ms. Williams.”It’s something which the whole community goes around,” she said.

King Lab School student Emma Stein, age 10, was excited to be at the banding. “I like how Evanston is a city in its nature,” she said.