The Anna’s Hummingbird (Calypte anna) is a common and resilient bird along the Pacific Coast of North America, recognized by the male’s iridescent rose-pink crown and throat. Unlike most North American hummingbirds, this species is largely non-migratory, often remaining year-round in its established territory. The difficulty in determining a precise lifespan for such small, fast-moving birds means that longevity data must be gathered through long-term scientific tracking.
Average and Maximum Lifespans
The overall average life expectancy for hummingbirds in the wild is relatively short, often cited in the range of three to five years. This number is significantly lowered by the extremely high mortality rates experienced by fledglings and juveniles in their first year of life. Anna’s Hummingbirds that successfully navigate their initial year face much better survival odds and are capable of reaching advanced ages. The maximum documented longevity for an Anna’s Hummingbird stands at a minimum of eight years and two months. This record was established when a banded male was safely recaptured and released during a banding operation in Arizona.
How Scientists Track Hummingbird Age
Lifespan data for Anna’s Hummingbirds is collected primarily through bird banding or ringing. This technique involves capturing the bird and affixing a minuscule, lightweight aluminum band, engraved with a unique identification number, to one of its legs. Only trained and federally permitted experts are authorized to perform this work, which includes taking physical measurements like wing, tail, and bill length, along with weight. Longevity is confirmed when a previously banded bird is recaptured years later, allowing researchers to calculate the exact time elapsed since the initial banding.
Key Factors Affecting Longevity
The most significant hurdle to a long life occurs during the fledgling period, as a majority of hummingbirds fail to survive their first year. This high mortality rate is due to inexperience, making them vulnerable to predators and environmental shifts. Surviving this initial stage is the greatest predictor of reaching an advanced age.
The extremely high metabolic rate of these tiny creatures places constant and intense demands on their survival. Anna’s Hummingbirds must consume more than their body weight in nectar and small insects daily to fuel their fast-paced existence, meaning any disruption in food availability can be fatal within hours. They cope with cold periods by entering a state of torpor, a deep, hibernation-like sleep that dramatically lowers their body temperature and metabolic rate to conserve energy overnight.
Other threats include natural predators, such as mantises, tree snakes, and larger birds like Western Scrub-Jays and American Kestrels. Competition for prime feeding territories is also fierce, as individuals must aggressively guard flower patches and feeders to ensure a reliable energy supply.