Some of those species adapted to pastures, only to have their numbers plummet again since the 1940's, when many pastures were converted to row crops. Wetland bird species have been similarly reduced with the drainage of 88% of the state's original wetland habitat. Forest bird species have also been strongly impacted as forest cover has been reduced by 69% since settlement. The remaining forest habitat has been changing rapidly due to logging, grazing, fragmentation, invasion of exotic species, and tree diseases. The loss of all kinds of habitat remains the greatest threat to native Illinois birds.

IAS members have been trying to offset some of the effects of habitat loss and change. In the 1960's, the Society helped Greater Prairie-chickens and Bald Eagles by raising money and giving it to state agencies and other conservation partners to help preserve land and provide habitat for these species. Beginning in the 1970's, the Society began to acquire land through generous gifts, and later purchases, for its own sanctuary system to preserve bird and wildlife habitat in Illinois.

The Society now has 8 major sanctuaries which range in size from 30 to nearly 500 acres. Its sanctuary system includes grassland and forest communities, as well as small wetlands. Some of the sites protect rare or endangered plants and animals. One sanctuary protects one of the few remaining stands of old growth Post Oak in the state. IAS continues to raise money for land acquisition to purchase high quality habitat when opportunities arise.

Stewardship is an essential part of our sanctuary program, and maintains the health and quality of the plant communities which support birds and wildlife. Baseline monitoring studies of birds and plants, and other studies which measure ecosystem change guide our sanctuary management. Other stewardship activities include the control of invasive and exotic plant species which have negative impacts on habitat, and using natural processes (controlled burning) when needed to maintain high quality communities.

Financial support of our sanctuary system is vital. Your contribution, earmarked for the sanctuary fund, can be mailed to IAS, PO Box 2547, Springfield, IL 62708. If you prefer to support stewardship at a particular sanctuary, please click on the links above for information on each sanctuary and its stewardship activities and needs.