Interesting Things – Reshaped Wings, Forest Birds, Evolution?

I came across an interesting article in Science News, September 12, 2009, called, “Rapid evolution may be reshaping forest birds’ wings,” by Susan Millius. Subtitle – “Trend for pointier appendages in heavily logged boreal forests, with blunter, rounder ones in reforested parts of New England.”

Boreal Chickadee (Poecile hudsonicus) by Daves BirdingPix

Boreal Chickadee (Poecile hudsonicus) by Daves BirdingPix

Records have been kept on birds that live in the boreal forest of Canada and parts of New England for the past centrury. These areas were heavily logged and left bare or reforested as in parts of New England.

When the records were analyzed, a trend developed. Wings of forest birds where the trees were logged and left bare were longer (approximately by 2 cm) and more pointed, whereas, the forest birds that had the trees replanted and the forest renewed, had shorter (by 2 cm) and rounder wings. They are comparing the same species of birds in both places.

“Mature-woodland species showed the clearest change in pointiness regardless of body size, Desrochers said. During the past century, their long wing feathers, or primary feathers, overall gained about 2.23 millimeters on average. That uptick roughly matches the magnitude of differences between sexes. For example, a female boreal chickadee’s wing today is about the length of a male’s in 1900, he said.

Desrochers also included more southerly species on his list, such as the scarlet tanager and hooded warbler. These birds had experienced a very different century. The landscape of New England, deforested during previous years, rebounded into green woodland again. And here, Desrochers found a trend back toward rounder wing tips. The eight mature-woodland species he studied typically had lost, on average, some 2.37 millimeters on those long primary feathers.

These species aren’t passive victims of environmental change, Desrochers said. As bird species face new challenges, they respond to the extent they can. “Birds are not like sitting ducks,” he said.”

David Winkler said, “It’s surprising that there’s so much change so fast.” He also noted, “doesn’t explicitly address whether the wings change by evolution or by some other process. Winkler said that in observing changes and invoking evolution, “we need to be careful.”

Black-capped Chickadee (Poecile atricapillus) by Kent Nickell

Black-capped Chickadee (Poecile atricapillus) by Kent Nickell

Well, of course, those statements caught my interest. I believe in a Creator who supplies his creation with tremendous capability to adapt and have their needs supplied. I believe in natural selection and variation, but not something turning into something else or “macro-evolution.” I think the bird changed “by some other process,” namely, God’s protective watch-care.

Reading through the comments left, several were of note:

“I wonder what the “evolution might be directed by the species itself” refers to. It’s obvious here that the evolutionary selection of birds with appropriately shaped wings is caused by external forces, nothing the bird is doing. Those birds in areas that are opened up which have slightly longer wings are able to raise more chicks, while those in areas that are being reforested that have more rounded wings are able to raise more chicks. The reason is that distance flying is done more efficiently with longer (and therefore pointier) wings, while maneuverability is required in heavily branched areas and is done with shorter wings.

As for whether the wings are being worn out by contact with branches, this would be evident because the wear at the tip would be obvious. Feather shafts don’t go the whole way to the end of the feather, so if the tips were worn off, it would be noticed”  by DM (very good comment)

“Could the shorter wings of birds in denser forests be due to greater feather wear from brushing against branches and foliage? Maybe all wing feathers start out pointy and simply wear into a rounded shape.” by KC

More searching on the internet turned up a remark about this article at Answers in Genesis with this very interesting statement:  “The report notes that “as bird species face new challenges, they respond to the extent they can.” This comports with the creationist view: God included a range of genetic information and adaptability in organisms to allow them to live properly in a range of habitats.

The scientists aren’t certain how significant a role genes play in the wing tip changes. Still, Cornell University ornithologist David Winkler noted, “It’s surprising that there’s so much change so fast,” and Desrochers calls “rapid evolution” the most direct explanation. The speed of the changes indicates how the created kinds could have speciated rapidly after the Flood. Centuries of accumulated changes between some populations from the same created kinds resulted in sexual incompatibility. However, in other kinds (such as canids; see above), populations retain the ability even if interbreeding is uncommon.”

Consider the ravens: they neither sow nor reap, they have neither storehouse nor barn, and yet God feeds them. Of how much more value are you than the birds! (Luke 12:24 ESV)

God is providing for the birds and we know He will provide for us, especially if we belong to Him.

Bolding is by Lee.

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