From the July 3, 2015, Chicago Tribune "Illinois Bison Busy As Rabbits" by Ted Gregory.
A while back I wrote about the first bison calf being born in the wild in Illinois in the last two centuries, but since then, another 13 have been born in this past spring at the Nachusa Grasslands, a prairie restoration project about 95 miles west of Chicago. The most recent calf was born Wednesday. Nachusa is located off Lincoln Highway near Franklin Grove.
This is promising, but even more so is that smaller mammals, including mice and voles are building nests of bison hair. An ecological balance will be reestablished.
Since the wild bison arrived at the 3,500 acre grasslands owned by The Nature Conservancy and the firt calf's birth, donations have increased 50%. They began acquiring land in the area in 1986. It is a national organization which has undertaken some 105 prairie restorations and gathered thousands of pounds of prairie plant seed which grows better with the presence of bison.