Trivia Question of the Week

Last week, when we posted about the capture and processing of bald eagles, we mentioned that, up until five years of age, eagle molting patterns can be used to determine how old a bird is. Past five years of age, when eagles reach adulthood and take on the characteristic appearance of their species, with a white head and tail, it's impossible to tell how old they are. So, how long do bald eagles live?

Hint #1: The fact that eagles don't mature until five years of age suggests that they're fairly long-lived-- animals that live shorter lives mature earlier.

Hint #2: In the age range when average Americans are beginning to settle down and think about having children, bald eagles are already well into adulthood.

Hint #3: If I were an eagle, I'd likely be nearing the end of my lifespan.

Hint #4: The longest-lived bald eagle documented in captivity reached 47 years of age, but keep in mind that animals in captivity tend to live longer than their wild counterparts.

Hint #5: An eagle's midlife crisis would likely occur about a decade after it obtained it's snow-white head and tail.

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If you guessed 20-30 years, right on! Recovery of USGS leg bands has provided information about how long eagles typically live, particularly for birds banded before they reach adulthood, when their age can be determined. Mortality rates for eagles are highest within the first couple years of life. Once eagles reach adulthood, they're less likely to die, so many eagles that reach this stage live reasonably long lives. Band recoveries have indicated that some wild eagles live into their mid-30's, but most fall within the 20-30 year range.