Vertabrates of the Flint Hills

Abstract

The Flint Hills of Kansas constitute an ill-defined area with no prominences, deserts) extensive water, or othar features that ordinarily are considered as barriers to the migrations of animals or in a,ny waa inimical to the well-being of animals that otherwise inhabit the midlands. This mass af ridgesS and breaks and valleys, however, constitutes the last major remnant of the formerly much more extensive tall grass prairie, with the tall grass species rapidly reduced westward. There is a definite gradient in rainfall from the east to west across the Eilint Hills and a gradient in temperature arld rainfall from south to north. The major factors that determine the success of vertebrates, then, change rapidly enough in this 60 X 240 mile area to become submarginal for sever31 species at one or the other extreme of the area. Aquatic species, of course, are limited by the availability of water The northern part of the Flint Hills is drained by the Kaw River and its tributaries and by the Marias des Cygnes River which connects to the Missour; River farther to the east. The southern two thirds, on the other hand, is drained by the Arkansas River, or its tributaries, namely the Neosho-Cottonwood, Verdigris and Elk Rivers and Caney and Walnut Creeks, Thus, the aquatic animals7 fish in particular i,n the northern part of the area are derived from the inhabitants of the Missouri River system) while those in the south are closely related to those of the Arkansas River system. Furthermore, the Kaw River and its broad flood plain constitute a natural passageway through the northerSn. Flint Hills, allowing direct communication from east to west while the Arkansas River bypasses the area, and its tributaries run from north to south forming long narrow passages into the heart of the region through which some interchange can be made with southern species. Of this system only the Cottonwood River provides a sort of east-west passage through the regiorl. Other than the fishes which are limited iln distribution to continuous water or are dependent on man's intervention, distribution of amphibia, reptiles, and mammals is distinctly affected by the Flint Hills and the gradient of temperature and rainfall within their limits. In the following discussio.n, I am considering the Flint Hills within the limit of Kansas. It may be assumed that that portion in Oklahoma will be found closely comparable to the area in Chautauqua and Cowley