636 DIFFERENCES BETWEEN WESTERN AND EASTERN RIRDS. 
Some birds, however, seem but little affected by the settlement 
of the country. The baywinged bunting, for instance, is scarcely 
more abundant in eastern Iowa than on the unbroken prairies in 
the western part of the state, nor are his habits different. The 
greater number breed among the pines of Minnesota, very few re- 
maining in any part of Iowa during summer. 
Some species increase rapidly on the first settlement of the 
country, and then decrease again. Of this class are the prairie 
hen and mallard. They find abundance of food in the corn and 
wheat fields; while the population is sparse and larger game so 
abundant, they are hunted very little; but as the population in- 
- creases, they are gradually thinned out and become in some 
cases exterminated. Other birds, as the quail, are wholly un- 
known beyond the frontier; and only appear after the country 
has been settled a short time. Still others, woodland species, ap- 
pear in regions where they were never known before, as groves of 
trees are planted, and thick woods spring up on the prairies, as 
soon as the ravages of the fires are checked. Thus, some species 
are introduced and some exterminated by the settlement of the 
country, while the numbers of almost all are more or less affected. 
The same changes have taken place in the Eastern States, and 
are still going on there, but so slowly as to be imperceptible. 
Here in Iowa, on the contrary, they are so rapid as to attract the 
attention of the most careless observer. 
The breeding habits of birds undergo considerable modification 
on the settlement of the country. In the wilds of Minnesota, £ 
never saw the nest of the robin elsewhere than in the tops of the 
tallest Norway pines. The crow, in similar localities, often builds 
on low bushes. The chipping sparrow nests in the same places 
a 
pains to conceal their nests. So far as my pills went, 
think that the robin, bluebird and some other small birds, breed 
little later in the season than in the settled regions, though I ie 
be mistaken. 
The real influence of man upon animals and especially on binds 
is scarcely yet appreciated, When the subject comes to be more 
thoroughly understood we shall find that not only are they. 
erned in their range and numbers through his agency, but thé 
even their natures and mental characteristics are changed as well. 
