Listen to this PodcastMore 60-Second Science
[The following is an exact transcript of this podcast.]
If you were a bird, how big could you be? Well, an ostrich can weigh 400 pounds—but it can’t get off the ground. So what if you want to fly? University of Washington scientists say it depends on how fast you can replace your flight feathers when you molt. The report is in the journal Public Library of Science Biology.
Feathers don’t last forever. So birds periodically shed their plumage and then sprout replacements. Small birds molt once or twice a year, and they replace their 9 or 10 primary flight feathers a few at a time over the course of a few weeks.
But bigger birds need bigger feathers. And that’s where the problem comes in. As birds increase in size, the rate at which they grow their feathers doesn’t keep up with their longer feather length. So if big birds tried to do like little birds, they’d spend the whole year molting—leaving little time for finding food or mates. [“Hey, whaddya doing?” “Still molting.”]
Some large birds, like honking big geese and 30-pound swans, get around the problem by forgoing flight while they get all their molting over with in one fell swoop. In other words, these birds of a feather defrock together.
—Karen Hopkin
For more, check out "Feather growth limits size of flying birds"
See what we're tweeting about
3 Comments
Add CommentDo we know conclusively whether the giant pterosaurs had feathers? And assuming not, I wonder what technology their wings used, instead of feathers (surely the skin-only approach that bats use doesn't give enough lift...?).
Reply | Report Abuse | Link to thisWhile larger feathers are the easy way to get bigger up to a point, what prevents the feather size to bird weight from changing, and perhaps feather numbers go up instead of feather size. Less efficient perhaps and limiting in other ways, but if the possibility arises, it would arise and work.
Reply | Report Abuse | Link to thisOne might look at the design of an albatross and decide that though efficient in flight, they might never be able to get off the ground without a long runway.....
Really appreciated the article . I have a sparrow that visits my deck , that happens to be minus all tail feathers. I was very concerned , but will save my worries until I see if he grows some new ones .Seems t be able to fly just fine without them.
Reply | Report Abuse | Link to this