Ongoing Study Yields Further Developments on Aging White-Tailed Deer
The ability to accurately age white-tailed deer facilitates evaluating management strategies, monitoring population trends and herd health, and making management decisions. Several years ago (Ag News and Views, April 1997), I reported results from an ongoing study we were conducting on the Noble Research Institute Wildlife Unit (NFWU) on aging white-tailed deer using tooth eruption and wear patterns. This technique was, and still is, the most frequently used field technique for aging deer. Our data demonstrated limitations associated with the aging technique, and we concluded that, based on tooth eruption and wear, we could confidently place Noble Research Institute Wildlife Unit deer into three age classes only fawn, yearling and adult. To date, subsequent data collected on the NFWU support this conclusion.
Our findings questioned the universal application of the technique for placing adult deer into specific age classes, and we called for further evaluation of the technique through the creation of known-age reference collections from other parts of the country. I am happy to report that some other researchers are doing just that. At the recent 26th Annual Meeting of the Southeast Deer Study Group, Mickey Hellickson, a biologist with King Ranch, Inc., in south Texas, reported on a reference collection they are establishing with more than 100 samples. Their findings relative to tooth eruption and wear patterns are very similar to ours, particularly in the 3.5 years and older age classes. As we found, there was a strong tendency to under-age the older age-class animals based on tooth wear. However, there is still no consistently applicable "fudge factor" which can be used to increase the accuracy of the technique.
The tooth eruption and wear aging technique remains a useful tool in deer management, when its limitations are recognized and used. In many management scenarios, the ability to place deer into fawn, yearling, and adult age classes is sufficient for making management decisions. Refinements of this technique and development of different techniques are more likely as more reference collections are established and evaluated.