A Bird’s Life – Guest Blog

Guest Blog by Judy Martin, Think Wild Volunteer

Aquila – Photo by Mike Gordon/Sunriver Nature Center

Aquila, the beloved Golden eagle housed at the Sunriver Nature Center & Observatory, was estimated to be 49 years old when she passed away in January 2024. While it is very difficult to determine a wild bird’s age, Aquila had originally come to the Nature Center in 1984 as an injured adult from Fort Rock, OR.  The next 25 years took her to Montana, before she was returned to the Nature Center in 2009 to be an exhibit bird.  Although she had been blind most of her life, she recognized staff at the Center and had a playful personality.  An amazing life story, especially given that most Golden eagles live less than half her age.

How unusual was Aquila?

How long do birds live? 

According to the American Bird Conservancy, birds can live between four and 100 years, depending on the species.  That’s quite a range!  Studies indicate that Golden eagles live between 14 and 20 years on average.  However, Golden eagles living in captivity, such as Aquila, have been recorded living into their 40s.  The deciding factor for a Golden eagle’s lifespan is whether the bird lives until adulthood.  Only half of young nestlings go on to fledge, and 25% of those will die in their first year.  An eagle does not reach full maturity until age 4 or 5.


Why is there such a range of lifespans among bird species?

Longer lifespan is often associated with features of a bird’s biology and natural history. Even within the same species lifespans vary.  For example, smaller owls like the Elf Owl can live up to five years; while larger species, like the Great Horned Owl, can live to be nearly 30. There are five attributes that may contribute to longevity (Source: American Bird Conservatory website – abcbirds.org):

  • Body size. On average, larger species tend to live longer than smaller species.
  • Number of chicks. Birds with longer lifespans often have fewer young, while those with shorter lifespans tend to have more.
  • Years to reach adulthood. Shorter-lived species tend to reach adulthood more quickly than longer-lived species.
  • Life on the ground. Birds that live and nest on the ground have often adapted for shorter lifespans than those that live higher up, such as in the shelter of the tree canopy.
  • Island life. Birds that live and nest on islands are often longer-lived than their mainland counterparts.

It is very difficult to determine the age of a wild bird.

Source: Ornithology.com

Once birds develop their adult plumage, they become nearly impossible to age in the wild.  Unlike humans and many other animals, they don’t turn gray; they don’t develop arthritis; and they don’t put on extra pounds with each passing year.  

Our knowledge of birds’ lifespans in the wild comes almost entirely from bird banding. The theory behind this technique is simple: If you catch a bird that has already been banded, you can confirm its age — or at least the time elapsed since it was originally caught and banded.  

In practice, though, aging birds from banding is more complicated than it seems. Only a small percentage of banded birds are ever observed again, and if they were adults when they were first banded, their starting age is unknown.

Estimated lifespans for some birds commonly seen in Central Oregon (Source: Ornithology.com) Caution: Just because birds can live a long time doesn’t necessarily mean that all individuals of the species do live that long.

Think Wild’s ambassador Red-Tailed hawk “Shar”.

Hawks (like Think Wild’s Ambassador Red-tailed Hawk, “Shar”) – 8-20 years

Eagles – 20-25 years 

Osprey – 32 years

Hummingbirds – 6-8 years

American Robins – 12 years

Cedar Waxwings – 13 years

American Crows – 15 years

Most songbirds – 8-12 years

World record holders for longevity:

Source: abcbirds.org

“Cookie” – a pink cockatoo lived to be 83 years old in captivity at the Brookfield Zoo near Chicago. 

“Wisdom” – a Laysan Albatross, at an estimated 72 years of age, is the oldest-known wild bird (confirmed by banding), shown laying an egg at the age of 68.

 

Wisdom, the world’s oldest known wild bird, has laid another egg. She is at least 68.
Source: smithsonianmag.org