A large crowd gathered at the library to watch as the four baby peregrine falcons were banded.

The next generation of peregrine falcons was banded and named on May 31 at the Evanston Public Library. Mary Hennen, an ornithologist with the Field Museum, and Matt Gies from the Shedd Aquarium were there to band the birds. Blood samples were also taken from each of the birds for genetic testing.

Wilbur, Rosalind, Lincoln, and Dewey hatched three weeks ago and their parents, Nona and Squawker, have been nesting at the library for four years. Ms. Hennen said that now the biggest concern is the young bird’s first flight, which could be in three weeks.