How a tiny songbird can fly 1,700 miles over open ocean

Apr 7, 2015

Laura Erickson/Cornell Lab of Ornithology/AP

By Joseph Dussault

It weighs only as much a tablespoon of sugar, and it flies almost two thousand miles over open ocean, without a single break.

Scientists can now conclusively say that the pocket-sized blackpoll warbler makes the longest overseas migration of any land bird. By fitting the birds with tiny geolocating “backpacks,” researchers were able to map out the grueling migration. Their findings appeared Tuesday in Biology Letters.

The blackpoll warbler, or Setophaga striata, is a songbird native to North America, weighing on average a mere 12 grams. Every winter, these tiny birds migrate to South America in droves – but for more than a half-century, scientists have been unsure exactly how they got there.

Other warblers native to the continent fly south through Mexico. But reports of blackpolls landing on boats in stormy weather suggest that they were taking an alternate route over the Atlantic Ocean. Some ornithologists were skeptical – the trek would be perilous, and a water landing would mean certain drowning for a fatigued bird. So an international team of researchers fit 40 birds in Vermont and Nova Scotia with tracking devices to follow the journey. And amazingly, the little blackpoll proved its mettle.


Read the full article by clicking the name of the source located below.

17 comments on “How a tiny songbird can fly 1,700 miles over open ocean

  • But how do these birds navigate, especially over open ocean ?

    A very interesting lecture by Jim Al-Khalili involving quantum effects in birds, (robins), and how they manage to navigate. But you will have to allow about an hour.

    Jim Al-Khalili



    Report abuse

  • Imagine if you had a toy battery powered helicopter or toy airplane. Imagine it staying aloft for three days.
    How much energy-denser would batteries have to be to compete with fat deposits in these birds?

    There is something that does not add up. Imagine an alcohol or kerosene powered plane. It should have an energy density on the same order of magnitude as fat. Whatever these birds are doing, they are much more efficient than our contraptions.



    Report abuse

  • Roedy:

    Whatever these birds are doing, they are much more efficient than our contraptions.

    Indeed ! But then evolution has had quite bit more time to improve the ‘contraptions’ than has Homo Sapiens.



    Report abuse

  • The article suggests that only half the birds survive the journey. I suspect that even those which make it are going to be so weak that there will be a fair incidence of death through exhaustion and predation. It’s a remarkable survival strategy.



    Report abuse

  • Ewan Apr 8, 2015 at 4:07 am

    The article suggests that only half the birds survive the journey.

    That would exert considerable selection pressure on the population, with the fitter, better adapted, birds surviving to breed.

    I suspect that even those which make it are going to be so weak that there will be a fair incidence of death through exhaustion and predation.

    I think one of the points of the migration route over the sea, is to avoid land based predators. The prevailing winds, can also help.

    I am also linking an article with more details, which suggests some birds take a rest on islands along the route.

    http://carnivoraforum.com/topic/10290201/1/
    In the fall the birds migrate from their breeding grounds across the northern latitudes. They converge on the Northeastern United States south to Virginia starting in mid-August. Part of the fall migratory route of the blackpoll warbler is over the Atlantic Ocean from the northeastern United States to Puerto Rico, the Lesser Antilles, or northern South America. To accomplish this flight, the blackpoll warbler nearly doubles its body mass in staging areas and takes advantage of a shift in prevailing wind direction to direct it to its destination. When they fly southward over the Atlantic they burn, 0.08 g of fat every hour. This route averages 3,000 km (1,900 mi) over water, requiring a potentially nonstop flight of around 72 to 88 hours. They travel at a speed of about 27 mph (43 km/h). Blackpolls can weigh more than 20 g (0.71 oz) when they leave the United States and lose 4 or more grams by the time they reach South America. Some of the blackpolls land in Bermuda before going on. Some birds, often with lower body weights, do not make it.

    The blackpoll warbler’s transoceanic flight has been the subject of over twenty-five scientific studies. Sources of data include radar observations, bird banding and weights taken, dead birds recovered from field sites and fatal obstacles. It is unknown if they feed on insects while in flight.

    Island stopovers at Bermuda and other places are evidence of migratory pathways. Most blackpoll warblers fly directly from northeastern North America over the Atlantic Ocean to their winter range. Data from nocturnal accidents, banding stations and sightings show that blackpoll warblers are rare autumn migrants south of Cape Hatteras, North Carolina, whereas north of Cape Hatteras they are common.

    I looks like island stop-overs were an earlier stage in the evolution of the migration route.

    The warblers fuel up on fat for the journey, going from 0.4 ounces (12 grams) to 0.6 ounces (16 grams), says lead study author Bill Deluca, an ecologist at the University of Massachusetts, Amherst. Some overachievers double in weight. “Basically, they’re these little meatballs with wings,” he says.
    Then they absorb internal organs they won’t need for the trip, like their intestines, to reduce excess weight, Deluca says. Reduced to fat, feathers, and muscle, the birds depart, taking advantage of trade winds for their journey south.

    The warblers can’t catch these winds on their way back, so they take an overland route in the spring, Deluca explains.



    Report abuse

  • The REAL puzzle is WHY??

    There must be something in their history to explain the ridiculous, inefficient and deadly nature of the journey; what was it that made the direct route unacceptable?
    Baffling.



    Report abuse

  • JimJFox Apr 8, 2015 at 10:38 am

    The REAL puzzle is WHY??

    There must be something in their history to explain the ridiculous, inefficient and deadly nature of the journey; what was it that made the direct route unacceptable?

    If you look at the link on my earlier comment, it mentions predators on the land route, a helpful prevailing wind on the ocean route, and a probable use of island hopping, before the selection pressures moulded the birds into longer range fliers when they missed the islands.



    Report abuse

  • Apologies, the time lapse between posting and appearance led me to believe that my message had been lost up the electronic Swanee River, with or without a paddle. Hence the repetition.



    Report abuse

  • Meanwhile in the Med, they have just proved once again that asking dumb-humans opinions in referenda, is no way to manage a planet!

    Hunters win Malta bird referendum on shooting ban – http://www.bbc.co.uk/news/world-europe-32274233
    Malta has narrowly rejected proposals to ban controversial spring hunting, during which migrating birds are shot before they can breed.

    The BBC’s Mario Cacciottolo in a tweet says that hunters’ association head Joe Perici Calascione is “ecstatic” about the outcome of the vote and has described hunting as an integral part of Maltese tradition.

    Critics accuse hunters of killing scores of birds – they say that turtle dove numbers have declined 77% since 1980

    They argued that the hunting season is abused by some hunters through the illegal shooting of protected species during a crucial migration period as birds fly over Malta into Europe.

    A second hunting season in autumn was not included in the referendum.

    Malta is the only EU country that allows recreational spring hunting.



    Report abuse

Leave a Reply

View our comment policy.