Birds of Kerr County, Texas

Abstract

HELMUT K. BUECHNER Texas Cooperative Wildlife Research Unit and Department of Fish and Game, Agricultural and Mechanical College of Texas, College Station, Texas. Kerr County appears to be on a dividing line between many eastern and western forms of bird life. It is situated on the Edwards Plateau, which is the southern termination of the Great Plains in central Texas. Approaching from the east, the Edwards Plateau is the abrupt rise in elevation encountered. The rise extends north through central Texas as the so-called first plateau. The change occurs at the Balcones Escarpment, a Cretaceous fault line that extends roughly from Dallas through Waco and Austin to San Antonio, and then westward to Del Rio. Elevations within Kerr County range from 1,000 to 2,300 feet. The topography varies from the level alluvial lands along the Guadalupe River to the hilly lands in the uplands. Drainage is principally by the Guadalupe River and its tributaries, although the Frio, Sabinal, Medina, and South Llano rivers also have their headwaters in the county. The deep alluvial soils of the Guadalupe Valley are utilized for cultivation; the thin limestone soils of the uplands for livestock grazing. River bottoms support heavy stands of cypress, water oak, hackberry, pecan, and walnut; whereas the dry uplands are covered by oak-savannah pastures, cedar brakes, and dense thickets of shinnery oak. The present bird list is based primarily upon specimens in the Texas Cooperative Wildlife Collection at the Agricultural and Mechanical College of Texas, and the following collections as indicated in the United States Fish and Wildlife Service records: Bio-