Sex and Age Indications from Upper Canine Teeth of Elk (Wapiti)

Abstract

Permanent upper canine teeth of elk (Cervus canadensis) differ morphologically according to sex. Canine eruption, development, and attrition are similar for each sex and are associated with age. Studies conducted during all seasons of the year in the Northern Yellowstone Elk Herd provided 580 pairs of upper canine teeth with respective lower jaws. Canine teeth were assembled on a reference board by sex and by year-class as indicated by replacement and wear patterns of cheek teeth of lower jaws. When paired canine teeth were assigned ages from the reference board and then compared with ages as determined from the corresponding jaws, calves, yearlings, and 2-year-olds were readily recognizable. Canine-assigned ages agreed with jaw-assigned ages 96 percent of the time for two older agegroups: 3-7 years and 8 years and older. Trials with students, to whom variations between teeth on a reference board were described, indicated the simplicity and accuracy of this method. Replacement and wear patterns of cheek teeth of lower jaws are reliable indicators of age in elk (Quimby and Gaab 1957). When lower jaws are absent from the animals being examined, a substitute source of similar information is frequently available and easily obtained. Successful elk hunters usually have in their possession the traditional trophy of their animal-the canine teeth, often called ivories, whistler, eye, elk, or bugler teeth. Murie (1951:99) noted that the size of upper canine teeth of elk were characteristic for each sex and also reflected the age of an animal. An extensive collection of paired upper canine teeth and corresponding lower jaws provided an opportunity to evaluate the reliability of canines as indicators of the sex and age-classes of elk. MATERIALS AND METHODS Elk studies in the Northern Yellowstone Herd during all seasons of the year from May, 1963, to March, 1966, provided 580 pairs of upper canine teeth and lower jaws. Forty-one additional samples, from hunting seasons, were available from other Montana elk herds. The age indicated from respective lower jaws (Quimby and Gaab 1957: 450) was assigned to canine teeth. Weights, measurements, and ratios of measurements of canine teeth varied considerably between age-classes and were also impractical to obtain at checking stations. Therefore, a different of designating canine ages was necessary for distinguishing various age-groups. Representative canines for each of the age-classes of males and females were assembled on a Riker mount for a reference series (Figs. 1 and 2). In trials, canines to be assigned age were placed on the glasscovered reference collection, distinguished for sex, and compared with age-classes represented. This comparison method proved rapid and reliable and was accepted in trials by biologists and checking station personnel. Unless specified, descriptions are predominantly for specimens obtained from September through February, a period which would include most hunting seasons. Teeth are described to the half-year but actually vary from 3-8 months. All canines were cleaned of flesh, and any pulp present was removed. 'A contribution from Federal Aid in Wildlife Restoration, Montana Project W-83-R.