Morphologic Variation in the Coyote, Canis latrans, in the Southern United States

Abstract

Morphologic variation in the coyote, Canis latrans, from the southern United States was examined using univariate and multivariate statistical analyses. The taxon was sexually dimorphic with male skulls larger for 20 of 21 characters assessed. Fourteen male and 12 female measurements showed significant interlocality variation. A matrix of correlation among characters was computed, and the first three principal components were extracted. These accounted for 87.9% of the total phenetic variance in the character set of males of 94.1% among females. Three-dimensional projection of localities onto principal components showed that, for both males and females, large individuals occurred in more eastern localities (male-eastern Texas, Louisiana, and Mississippi; female-Louisiana, Tennessee, Arkansas, Mississippi, and eastern Texas) and smaller animals occupied western localities (western Texas, Oklahoma, and Missouri). In general, coyotes were most similar to those in nearby geographic areas. Large size for both sexes was positively correlated with high actual evapotranspiration. The coyote, Canis latrans, is widely distributed in North America (Hall, 1981). Much natural history and management information relating to this species has been collected in many parts of its range. Bekoff (1977) summarized much of this available literature. Canis latrans is versatile in relation to food and habitat and appears to be a species that has met the challenges of the modern world. At a time when many species are declining in numbers, C. latrans continues to occupy traditional ranges as well as escalate its distribution into new areas. One region of recent colonization is the southeastern United States. Gipson (1978) reported no wild Canis, other than occasional feral dogs and extremely isolated pockets of red wolves, occurring in the southern states east of the Mississippi River from 1900 until about 1965. Coyotes moved eastward through Tennessee, Mississippi, and other eastern states during the 1960's and early 1970's. The immigration of C. latrans into the southeastern United States offers a rare opportunity for systematic study. The purposes of this study were to examine morphologic variation in C. latrans in the southern United States and to appraise the similarity of coyotes from newly colonized areas of the southeastern United States with those from established portions of the range in the southwest. MATERIALS AND METHODS-We recorded 21 linear skull measurements (Fig. 1) from 552 adult C. latrans. Adult specimens were determined according to criteria of Nellis et al. (1978). Skull dimensions were measured with a dial height gauge (in inches and converted to millimeters) and dial calipers to the nearest 0.1 mm. Characters were chosen following the logic of Kennedy and Schnell (1978). To reduce heterogeneity in sample sizes, specimens were grouped for statistical analyses according to state boundaries with the exception of animals from Texas which, due to the large size of this state, were treated as eastern and western localities. States represented by less than This content downloaded from 157.55.39.112 on Wed, 07 Sep 2016 04:38:02 UTC All use subject to http://about.jstor.org/terms The Southwestern Naturalist