How do we estimate ages by looking at the root of a tooth?
Ages can be estimated based on the number of annual “rings” observed in a cross section of the root of a tooth. Similar to aging a tree by its rings, teeth of many wildlife species have annuli (rings) that give us an idea of how old the animal is. Tree rings are basically constrictions in growth that occur during winter or times when the tree doesn’t grow as fast. Teeth from young animals are basically hollow, so unlike trees that grow larger as the tree ages, in animals the “hollow” area fills in as the animal ages. During periods of reduced growth there is a constriction that is visible on a cross section of the root tip. The technique works better for some species than others, but in general it provides a way of getting a relatively good age estimate. These estimates provide managers with information about age trends in populations. When used in conjunction with other information, age trends help managers evaluate how populations are doing and are used to make management decisions to improve conservation of the species.
For more information regarding cementum analysis, go to the Matson's Lab website.