Birds are fascinating creatures that exhibit an incredible diversity of shapes, sizes, colors, and behaviors. Many birds are specially adapted for flight and spend most of their lives on the wing. But which bird spends the greatest proportion of its life in the air? Let’s examine some of the leading contenders for the title of the bird that flies most of its life.
Swifts and Swallows
Two groups of birds that immediately come to mind when thinking of aerial specialists are the swifts and swallows. Both groups are incredibly agile fliers with long, swept-back wings and streamlined bodies built for speed and maneuverability in the air.
Swifts in particular seem to be designed to almost never touch down. Their short legs and tiny feet make them clumsy on land, barely able to perch – let alone walk or run. Once swift nestlings fledge and take their first flight, they may remain airborne for the next 2-3 years until establishing a breeding territory. They feed, drink, mate, and even sleep on the wing.
Some swifts are known to stay airborne for up to 10 months without landing! The common swift has been well studied and is estimated to spend over 95% of its lifetime in flight. Recent tracking studies have shown the Alpine swift can go nearly 6 months without touching down. Both species only land to breed and raise their young.
Bird | Estimated time in flight |
---|---|
Common swift | 95% |
Alpine swift | 80-90% |
Swallows are also highly aerial, feeding on flying insects that they catch on the wing. However, they do not take aerial living to the extreme of swifts. Swallows frequently perch and roost, and do spend time walking or hopping along the ground. Overall, swallows likely spend around 50-75% of their time in flight on average.
Frigatebirds
This group of large seabirds are sometimes known as ‘pirate birds’ for their habit of harassing other birds to steal their prey. Frigatebirds have the largest wing area to body mass ratio of any bird, making them supremely adapted for an aerial lifestyle. Their feathers are not waterproof, so they are unable to land on the ocean to rest.
Frigatebirds have been tracked staying aloft for weeks at a time, only returning to land briefly to nest and provision their chick. They are estimated to spend a remarkable 95% of their lives on the wing hunting for fish and other prey.
Albatrosses
These iconic oceanic birds are among the most aerial of all birds. Their immense wingspans allow them to soar over vast distances with hardly a flap, exploiting wind gradients and dynamic soaring techniques.
Albatrosses are pelagic, coming to land only to breed. They may forage across thousands of miles of open ocean, remaining airborne for many days or weeks at a time. Satellite tracking has revealed the wandering albatross may stay aloft for over 40 days! Overall, albatrosses are estimated to spend 85-90% of their long lives on the wing.
Bird | Estimated time in flight |
---|---|
Frigatebird | 95% |
Albatross | 85-90% |
Terns and Noddies
Terns are coastal and inland species that plunge-dive to catch fish. They migrate long distances and remain almost perpetually on the move. The Arctic tern makes the longest migration of any animal on Earth – up to 50,000 miles annually during its 20+ year lifespan. Given these endless journeys, terns must spend most of their lives in flight. Recent research estimated terns are in flight around 80% of the time.
The black noddy is a tropical seabird related to terns. Noddies remain airborne for days or weeks at a time, coming to their breeding islands only briefly to raise chicks. Their time budget has been estimated around 75-85% in flight hunting for fish and squid.
Petrels and Shearwaters
Like albatrosses, these tubenoses are pelagic seabirds that live most of their lives roaming far offshore. They dip down to snatch prey from the waves or pursuit-dive for fish and squid.
Petrels and shearwaters only visit land to breed, remaining at sea for the rest of the year and logging huge ocean migrations. Great shearwaters migrate from breeding grounds in the southern hemisphere to North Atlantic waters off New England each year. Satellite tags show they may fly more than 47,000 miles in a year! Petrels and shearwaters likely spend 80-90% of their lives airborne.
Bird | Estimated time in flight |
---|---|
Arctic tern | 80% |
Black noddy | 75-85% |
Shearwaters | 80-90% |
Petrels | 80-90% |
Year-Round Aerial Lifestyles
Many of the oceanic birds we’ve considered migrate huge distances when not breeding, enabling a highly aerial, pelagic existence year-round. But some species maintain a primarily airborne lifestyle even during their breeding season on land.
Swifts, for example, remain airborne continuously through breeding, nesting in crevices and cavities where they can drop in and out to provision young. Swifts even copulate in flight! Likewise frigatebirds and terns continue aerial foraging while attending nest sites and chicks. Albatrosses at breeding colonies make frequent foraging flights out to sea to collect food for the chick.
These adaptations enable certain bird species to minimize time spent walking, swimming or sitting on the nest. Instead they are specialized for a non-stop flying lifestyle.
Conclusion
So which bird spends most of its lifetime in flight? Based on current knowledge, it seems swifts and frigatebirds take first prize, remaining airborne over 95% of their lifetimes. Other extremely aerial contenders include albatrosses, shearwaters, petrels and terns, which may spend 80-90% of their lives aloft. Even among birds, these species show some of the most extreme adaptations for aerial existence. Their mastery of flight allows them to traverse immense oceans to forage widely for prey while hardly ever touching down on solid ground. For these birds, the sky is home.