Posted on 11/08/2011 7:48:33 PM PST by Free ThinkerNY
Birds in central California are significantly larger than they were 25 to 40 years ago, and researchers believe it may be because they are bulking up in body weight to ride out severe storms related to global climate change.
Over the last 25 years, a robin, for example, has increased about an eighth of an inch in wing length and about 0.2 ounces in mass, according to a paper published online in Global Change Biology.
The findings fly in the face of assumptions based on an ecological benchmark known as Bergmanns rule: Birds and mammals tend to be larger at higher latitudes, perhaps to conserve body heat. Under this reasoning, birds and mammals would get smaller as they adapted to rising global temperatures.
But they also suggest that explanations for the bigger birds are more complex, according to researcher Jill Demers, executive director of the San Francisco Bay Bird Observatory.
The degree of physical change over a relatively short scale of time is remarkable and surprising, Demers said. Similar studies in Pennsylvania and Europe, for example, show that birds there have decreased in size over the past several decades.
Overall, birds in central California have grown an average of 2% to 5% in body weight and wingspan, said Rae Goodman, who discovered the trend while working as a graduate student at San Francisco State University, analyzing data from thousands of birds caught and released each year near San Francisco Bay and the Point Reyes National Seashore.
More study is needed to determine whether these changes are good for central California birds and how they affect food chains, Goodman said.
(Excerpt) Read more at latimesblogs.latimes.com ...
A: Here, kitty-kitty-kitty!
Global Warming on Free Republic
Canary be more series!
Have they considered steroids in the water?
What about growth hormones from cattle trickling down the food chain? See? It really IS BS!
Maybe worms are getting larger, so only larger birds are able to deal with them.
According to Darwin, the adaptation [NOT ‘evolution’] comes in response to environmental changes, not in anticipation...unless there's thiotimoline in the water or food.
Try looking up pictures of the “white crowned sparrow”; it winters in Texas.
I looked up a pic.
Not the same bird. It didn’t have the black stripes on its head- just a patch of white feathers on its head.
It was with a group of house sparrows.
(thanks :) )
You know how Suzette is about her bird feeder.
These crows start showing up out of nowhere.
She’s all over my back to get rid of’em.
“The crows are too big for the bird feeder,” she says.
- I don’t remember seeing crows around here before. - Oh, big bastards too.
That’s why I got the gun. I’m gonna pop a few.
~Art Weingartner
I would think birds would get smaller with increasing temperatures because warmer air is less dense than colder air thus and flying in less dense air would be more energy intensive.
Sometimes it's just bird doo.
It was feathers in this case. :)
Must be a Muslim bird!
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