Determining Animal Age

Various methods exist to estimate an animal's age, ranging from physical characteristics to scientific testing. The accuracy of these methods can vary greatly depending on the species and available information.

Teeth are often indicators of age in animals. Wear patterns, tooth growth, and replacement stages can provide age estimates, especially in mammals like horses, elephants, and domestic pets.

In some species, bones reveal age-related changes. For instance, the fusion of growth plates can indicate maturity in animals, while certain bone density and structure changes can imply advanced age.

Birds and reptiles can be aged by examining their feathers and scales, respectively. Seasonal molting patterns, coloration, and scale ring counts can provide clues to their age, albeit with varying precision.

For long-lived sea creatures like tortoises and clams, radiocarbon dating of their shells offers a scientific method to determine age, with some clam species living for over 500 years.

A less known technique involves analyzing the proteins in the eye lens, which remain largely unchanged from birth. This method can accurately determine the age of fish and some mammals.

Recent advances in genetic research have led to the development of 'epigenetic clocks,' which measure DNA methylation levels to estimate the biological age of an animal, showcasing the intersection of age and genetics.

Whales can be aged by analyzing the layers in their earwax, similar to tree rings, revealing their life history and even pollution exposure.