THE ECOLOGICAL SUCCESSION OF MAMMALS IN CHAM- 
PAIGN COUNTY: 
In the two accompanying charts (Pl. XX VII. and XXVIII.) an 
attempt has been made to represent graphically the variation in 
the abundance of the principal species of mammals in this region 
since the advent of white men. The second one is purely chrono- 
logical, and applies only to Champaign county. The first one, 
however, represents the variations in the abundance of our mam- 
mals as related to the degree in which advancing civilization has 
modified primitive conditions, and is therefore more general in 
character, and should in a good degree be true for other sections 
in the prairie region of the Mississippi Valley. 
A brief explanation of the nomenclature used in this chart to des- 
ignate the progressive stages of civilization follows, the order ob- 
served corresponding to their consecutive occurrence. 
(1) The period of the explorer and hunter. During this period 
the physiographic condition of the country remained unchanged, 
but the numbers of certain large animals were greatly diminished. 
(2) The period of the squatter and the range. In this period set- 
tlements were begun, usually in timber near streams. Only a very 
small portion of the country was enclosed by fences or under culti- 
vation, the settlers feeding their horses, cattle, and hogs largely on 
the natural products of the prairie and the forest. They were 
obliged to wage war on the larger carnivores in self-defense, and 
they hunted the most valuable fur-bearing animals for gain. 
(3) The period of settlement. This is the time during which the 
land was practically all taken up by settlers or land speculators. 
Pasturage on public domain ceased, and considerable portions of the 
land were enclosed. Timber for the construction of buildings and 
fences was entirely from the local supply, and considerable areas of 
woodland were cleared for cultivation. In consequence of these 
inroads into the forests and the settling of the prairie the larger 
animals still remaining, such as deer, wolves, and wildcats, were 
greatly thinned out, but the extensive wooded-belts along th 
rivers still sheltered a few of them. 
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