Rapid Evolution May Be Reshaping Forest Birds’ Wings
source: http://www.sciencenews.org/view/generic/id/46471/title/Rapid_evolution_may_be_reshaping_fore...
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- DeliaTheArtist
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"When trees fall in the forest, unheard or not, they may change the shape of bird wings.
As logging whittled away at Canada’s vast boreal forest during the past century, bird species that frequent mature woodlands developed somewhat pointier wing tips, says André Desrochers of the Center for Forest Research at Laval University in Québec City.
During the same period, forests expanded in New England. Mature-woodland species there trended toward rounder wing tips, he reported August 13 in Philadelphia at a meeting of the American Ornithologists’ Union.
Sharper points on wings typically prove more efficient than blunter shapes during sustained flight, Desrochers says. But previous research on wing shapes and flight also found a cost for those points. On tight maneuvers threading 3-D mazes of branches, pointy wings lose out to rounder ones.
Several other studies have noted wing-shape differences within the same species if some populations migrate and some don’t. House finches in the eastern United States that follow the seasons, for example, tend toward sharper wings than western, couch-potato house finches.
Desrochers said he began to wonder whether human activities that leave forests in fragments might influence wings the same way migratory lifestyles do. Loggers chewing away at the conifer forest that once blanketed most of Canada has meant that birds now fly farther than their ancestors to find prime territories and mates. Feeding the relentless gaping mouths of chicks in tattered forests also meant longer commutes, and all this extra flying might change the balance of trade-offs for wing shape."
As logging whittled away at Canada’s vast boreal forest during the past century, bird species that frequent mature woodlands developed somewhat pointier wing tips, says André Desrochers of the Center for Forest Research at Laval University in Québec City.
During the same period, forests expanded in New England. Mature-woodland species there trended toward rounder wing tips, he reported August 13 in Philadelphia at a meeting of the American Ornithologists’ Union.
Sharper points on wings typically prove more efficient than blunter shapes during sustained flight, Desrochers says. But previous research on wing shapes and flight also found a cost for those points. On tight maneuvers threading 3-D mazes of branches, pointy wings lose out to rounder ones.
Several other studies have noted wing-shape differences within the same species if some populations migrate and some don’t. House finches in the eastern United States that follow the seasons, for example, tend toward sharper wings than western, couch-potato house finches.
Desrochers said he began to wonder whether human activities that leave forests in fragments might influence wings the same way migratory lifestyles do. Loggers chewing away at the conifer forest that once blanketed most of Canada has meant that birds now fly farther than their ancestors to find prime territories and mates. Feeding the relentless gaping mouths of chicks in tattered forests also meant longer commutes, and all this extra flying might change the balance of trade-offs for wing shape."
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bailey78
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How much has the Modern Man changed in the last hundred Years??
- 2 years ago
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bailey78
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bailey78
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Change is never ending. if you look at the world as a time line then you will see a lot of change. especialy In the past four or five hundred years Hell the last hundred yeas have seen the death of how many speceis. many critters have had to change to survive in the modren world. (Sorry for the spelling I'm working on that)
- 2 years ago
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bailey78
