The lifespan of wild deer is highly variable, dependent on a number of factors. Deer that forage on more woody foods tend to grind down their teeth quickly, they literally die of starvation when they lose the ability to properly grind their foods (although they are otherwise perfectly healthy). Hunting and predator pressure are significant and also highly variable. That being said, the published data indicate that the record longevity for both captive and wild deer is just over 20 years.
