2013 November NN – Answering the Age Old Question. How Long Do Birds Live?

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A 21-year-old bald eagle gets released by Liberty Wildlife.

A 21-year-old bald eagle gets released by Liberty Wildlife.

Any animal in captivity, whether it’s in a breeding program at the zoo, an education ambassador like Liberty’s non-releasable education birds, or simply someone’s pet dog at home, is facing a much smaller list of dangers than the creature that spends every waking moment in the unforgiving world of nature. A captive animal doesn’t have to deal with predation or competition for limited resources, and it generally has its food provided for it, meaning that disease and the natural wear that comes with aging are its only real foes. Captivity certainly brings its own set of issues, but for the sake of simply discussing how long a given bird can live, captive specimens provide a useful piece of information, a sort of biological reference point for determining how long an animal could theoretically last if it weren’t for the many factors governing normal survival.

So just how long do birds live, in captivity and the wild? Let’s start with the red-tailed hawk, one of the most common and conspicuous raptors in North America. The National Geographic Society lists these wild birds as living around 21 years on average.¹ Washington State University aims more conservatively, around 10 to 15 years.² Whenever we look at general averages, though, it’s important to remember that conditions are by no means uniform, even for birds of the same species. Red-tailed hawks, for example, are extremely prolific birds, and can be seen from one end of North America to the other. A red-tail living in rural farm country in the Midwest, where there are ample amounts of rodents to satisfy its hunger, might have a better time of it than his cousin living in the arid southwest, where prey species are often very selective about when and where they brave the midday sun. Natural phenomena like droughts, which can impact entire ecosystems, undoubtedly influence span and quality of life for any number of animals as well. Average lifespans can easily rise or fall over a given period depending on whether it’s a time of feast or famine. Still, 20 years isn’t bad by any means. For context, captive red-tails, provided with a steady diet and effectively immune to predation, have reached 30 years of age.³

Bald eagles typically live 20 to 30 years in the wild, a very impressive span; in captivity, however, at least one bald eagle reached the ripe old age of 47.⁴ Golden eagles have comparable statistics. The noble great-horned owl has an average life expectancy ranging anywhere from 10 to 15 years in the wild, though once again, captive individuals can live into their late 20s.⁵ Using these numbers as a baseline for similar species, most raptors seem to have at least a decade of life ahead of them, provided they can withstand the withering first-year mortality rate that claims over half of all young raptors. In captivity, that age length can go up, and in some cases, even double.

Not all birds are so lucky, however. Consider the Gambel’s quail, a ground-based little game bird well-known to residents of Arizona. Here we have a prey species, not a predator. Can they look forward to anything approaching the lifespan of a hawk or eagle? Unfortunately, no. A Gambel’s quail can consider himself long-lived if he reaches a year and a half.⁶ A rare handful of individuals have incredibly pushed the envelope to 4 years, a feat that puts them almost beyond the count of reckoning for most Gambel’s quail. By and large, though, life for this species is short and unforgiving. Birds of prey might face incidental predation, and they certainly deal with daily competition, but life as a genuine prey species leaves a lot to be desired when it comes to longevity.

It may sound as if prey species, including our little Gambel’s quail, got the short end of the stick when it comes to life expectancy. Every animal has its own criteria for survival though, its own challenges to meet. The challenges are different, but so are the expectations. A Gambel’s quail that lives a year and a half has managed to survive every day of its life in the face of threats from any number of predators. That’s an incredible accomplishment. The hawk that reaches 15 years of age has had to do so in the face of ever-changing food supplies, stiff competition from other hunters, and the simple fact that a predator’s lifestyle leaves almost no margin for error: failing to consistently catch prey means certain death. Survival, under any circumstance, is a daily struggle and the ultimate triumph. How long you ultimately live doesn’t matter. What matters is that, whether to 15 or a year and a half, you survived.

¹ http://animals.nationalgeographic.com/animals/birds/red-tailed-hawk/
² http://news.wsu.edu/2011/11/14/wsu-home-to-oldest-red-tailed-hawk-on-record/#.UnfREZDn-Uk
³ http://news.wsu.edu/2011/11/14/wsu-home-to-oldest-red-tailed-hawk-on-record/#.UnfREZDn-Uk
http://www.philadelphiazoo.org/Animals/Birds/Birds-of-Prey/Northern-Bald-Eagle.aspx
http://animals.nationalgeographic.com/animals/birds/great-horned-owl/
http://neotropical.birds.cornell.edu/portal/species/overview?p_p_spp=84871

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