A large per cent of the recent publications in natural history and related subjects give evidence of a great depletion in our supply o native wild animals, due mainly to encroachments on territory and depredations on number by the white man. This fact is quite obvious to anyone who will turn for even a short time to natural conditions. In taking up the study of a particular area, it is hoped that the situation v:ill be mare or less typical. Inevitable allowances must be made for variations in local conditions, but the fundamental facts should be applicable to many localities.
As an example of the white man's intrusion into a wilderness area, the vicinity of Corvallis, regon has been chosen. The main advantage of this area in the present study was its nearness and conseouent availability of material. Furthermore, there are still a few areas in the vicinity which approach the primitive conditions and help to serve as a check. The fact that the area is, to a large extent, prairie gives opaortunity to test the soundness or at least one logical speculation. When the white man settles a prairie area, the habitat change is not so drastic as in the clearing of rorest lands, the opening up of desert areas, or the drainage of swamps. Does the animals life show similar trends? Lastly, one can see what forms are attracted or repelled by the presence of a city of the size of Corvallis.
Observations in this study are confined to the city of Corvallis, the fields surrounding It, and the last few miles of the Mary's River valley. (See Plate I). The dense river bottom growth of the Mary's tends to encourage animal forms which might otherwise stay in the adjacent hills. Any references to other parts of the Willamette Valley or state 1l1 bo satisfactorily linked to the area delimited.
Corvallis is close to the west side of the Willamette Valley. To the east of the town is the Willamette River. From the south side of town, along which flows the Lary's
River, the prairies of the valley stretch flat and level to distsnt hills. To the southwest of town, at about a half-mile distant, a low oak and fir-covered hill breaks
the level and is the nearest example of the higher hills which rise on the west and northwest of the city at a distance of one or two miles. The higher fir-clad hills of the coast range are west about six miles. These send out an eastward spur which is only two or three miles north of the city. This spur stops short of the Willamette River, leaving a narrow strip of flat land between.