Are the New and Old World wapitis ( Cervus canadensis ) conspecific with red deer ( Cervus elaphus )?

Some taxonomists have classified red deer and wapiti as being conspecific (Ellerman & Morrison‐Scott, 1951; Flerov, 1952); others have split them into two species, Cervus elaphus and Cervus canadensis (Hall & Kelson, 1959; Whitehead, 1972). The decision has been made each time largely on the basis of the size and form of the antlers, the proponents arguing that antler form is a good genetically‐based character, while the opponents view the antlers as being phenotypically very variable, depending largely on the environment for their formal expression. To avoid this controversy, we have used skull measurements, and only female material to reduce the possible effects of bias due to selection by hunters. The enzyme study methods of Gyllensten et al. (1983) and Dratch & Gyllensten (1985) were considered inappropriate as they may reflect only physiological relationships, and rely on living material. Several races of New and Old World wapiti are now either extinct or very rare. Moreover, skull morphology will remain the basis for the classification of most vertebrate species. Sixteen variables, comprising length, breadth and depth measurements, were measured on 298 skulls, representing most of the different races of red deer and wapiti in both the Old World and the New. These sets of variables were analysed by Principal Component Analysis, and the first two components, accounting for 86.4% of the total variance, were plotted as a graph. The first component was clearly a measure of skull size, while the second component gave the greatest weightings to the breadth of the nasals and depth of the nose, in other words, skull shape. All the Old World red deer and wapiti samples formed a continuum of variation in skull size and shape; the only discontinuity being between these races and the North American wapiti, which differed from them mainly in size. The latter could therefore be classified as a subspecies of red deer, Cervus elaphus canadensis . However, because differences in other characters such as behaviour and reproduction are so slight, there appears to be no justification for distinguishing between them at the species level.