By the late 1870s, Illinois had lost a type of species overwhelming in its importance to the ecosystem function. Large prey animals such as wolves and mountain lions once controlled the number of big herbivores such as deer. While coyote and vehicle numbers continue to increase in McLean County today, neither are effective in controlling healthy deer populations.
White-tail deer control, by their grazing, browsing, and trampling, the habitat on which small rodents, flowers, and butterflies depend. Finally, the rodents and vegetation provide a food source for other herbivores and carnivores.
Winters in central Illinois are not severe enough to significantly reduce populations. The reserves are not self-contained. The fact that surrounding agricultural lands provide an artificial and virtually unlimited food source necessitates a balance of human management.
Less obvious is the intrusion of introduced species. As native species are reduced by an imbalance of deer populations, introduced species, such as the multiflora rose, may increase because of higher tolerance levels to browsing.
If you have any questions, please contact the McLean County Department of Parks and Recreation at (309) 434-6770.