trappnman--I am not an authority on much of anything, but I do have the tooth chart for aging coyotes and that appears below here. I'll also list the text that explains how to use the various stages of wear to guesstimate a coyote's age. Lots of variables here, so this is not an exact scientific way to age a coyote, but should give you some idea. I think PH (Pete Hauer [sp]) on the GGVG board is doing some type of chemical analysis of teeth to try to determine age.
Aging Coyotes (Taken from a posting by AZWill on Shade Tree Hunting Forum, 3/6/2000)
In the field, coyotes are normally aged in four categories or classes: (1) Pups; (2) Yearlings; (3) Mature; (4) Old.
At six months the pups normally have their permanent teeth and weigh between 12 and 16 pounds. Young coyotes retain a juvenile face until about eight months old.
At one year coyotes are fully-grown, seldom have much body fat, and their canine and incisor teeth are white and sharp showing no wear.
The above figure represents average tooth wear in a coyote, by years, at mid-winter.
1 yr. – Incisors all rounded; no wear facets; canines sharp, incomplete.
2 yr. – Incisors inner cusp blunted; distinct wear facet; notch distinct; incisor (1) slightly blunted; canines complete.
3 yr. – Incisor flat, notch barely visible; incisor (1) almost square, inner notch distinct, incisor (2) inner cusp half gone; other incisors showing some blunting.
4 yr. – Incisor flat; dentine showing, notch gone; incisor (2) almost flat, incisor (1) worn to inner notch; incisor (2) blunted; both notches visible.
5 yr. – Incisor (1, 2) flat, notches gone; incisor (3) notch visible; incisor (1, 2) flat both inner and outer notches gone, incisor (3) distinctly blunted.
6 yr. – Lower incisors essentially flat across with only tiny notch in incisor (3); incisors (1, 2) flat across, all notches gone; PM (pre-molars) cusps showing wear.
7 yr. – Notch gone from incisor (3), upper incisors flat except incisor (3); canines and all cusps of PM and M (molars) distinctly worn.
Mature coyotes, 2 to 6 years old, have teeth with an increasing degree of wear on the canines and incisors and the animals are heavier in body weight. Older animals of 7 years or more may have teeth that are beginning to yellow and usually show wear on all the teeth. The canine and incisor teeth are sometimes broken or missing.
Perhaps you could contact Steve Allen, retired furbearer biologist who used to be with the North Dakota Game & Fish Department. I believe he has done radio collar studies on both coyotes and fox and has published a number of articles on that research. He used to be a moderator on this board. I'll e-mail his e-mail address to you.
Hope this helps you in some way.
Silverfox