The Taxonomy and Distribution of the Tiger Salamander in Colorado

Abstract

Three subspecies of Ambystoma tigrinum occur within the state of Colorado. A. t. melanostictum occupies the northwestern corner south to the Uncompaghre Plateau and east to the mountains. A disjunct population is found in Jackson and Grand counties. A. t. nebulosum is found in the high central and south western portions of the state and extend northward, surrounding the disjunct population of A. t. melanestictum (except at the Wyoming border), and separating the disjunct population from A. t. mavortium of the eastern plains. There is a broad area of intergradation between A. t. nebulosuns and A. t. mavortium along the eastern ranges of the mountains and in Park County and the San Luis Valley. Trans. Kaxls. Acad. Sci., 75 (2), 1972. Since 1875 when Yarrow Srst reported the occurrence of the tiger salamander, Ambystoma tigrivgm Green, in Colorado, there have been reports of unusual occurrences of the animal or restricted aspects of its life history within the state, but no comprehensive studies of the animal have been made. Hamilton (1949) in an unpublished master's thesis dealt with a local population whereas Hahn (1968) in another unpublished master's thesis included Ambystoma tigringm as part of a general study of the herpetofauna of the San Luis Valley. Other local studies have been reported by Prosser (1911) and Burger (1950). The only published material of a general nature and applicable to Colorado in particular wa(s produced by Ellis and Henderson (1913, 1915), Maslin (1959) and Smith, Maslin and Brown (1965). This last group of publications deals with distribution. The study of which this paper is a part was initiated in 1963 while still on active duty with the United States Air Force and continued until 1967. The project was the basis for a dissertation submitted in partial fulfillment of the requirements for the Ph.D. at the University of Colorado. The purpose was to determine the taxonomy, distribution and ecology of Ambstoma tigrinum within the state of Colorado. Much of the data are new and are based on the observation of more than 20,000 animals in the field of which approximately 2000 were secured and preserved. Most are now catalogued in the University of Colorado Museum (UCI\I) . This content downloaded from 157.55.39.180 on Tue, 27 Sep 2016 04:17:28 UTC All use subject to http://about.jstor.org/terms