Climate change 'makes birds shrink' in North America

BBC News ^ | 3/12/10 | Matt Walker

[NormsRevenge]

Songbirds in the US are getting smaller, and climate change is suspected as the cause.

A study of almost half a million birds, belonging to over 100 species, shows that many are gradually becoming lighter and growing shorter wings.

This shrinkage has occurred within just half a century, with the birds thought to be evolving into a smaller size in response to warmer temperatures.

However, there is little evidence that the change is harmful to the birds.

Details of the discovery are published in the journal Oikos.

In biology, there is a general rule of thumb that animals tend to become smaller in warmer climates: an idea known as Bergman's Rule.

Usually this trend can be seen among animal species that live over a range of latitude or altitude, with individuals living at more northern latitudes or higher up cooler mountains being slightly larger than those below, for example.

Quite why this happens is not clear, but it prompted one group of scientists to ask the question: would animals respond in the same way to climate change?

To find out, Dr Josh Van Buskirk of the University of Zurich, Switzerland and colleagues Mr Robert Mulvihill and Mr Robert Leberman of the Carnegie Museum of Natural History in Rector, Pennsylvania, US decided to evaluate the sizes of hundreds of thousands of birds that pass through the Carnegie Museum's Powdermill ringing station, also in Pennsylvania.

They examined the records of 486,000 individual birds that had been caught and measured at the ringing station from 1961 to 2007.

[NormsRevenge]

physical adaptation to one’s environment is nothing new.

I wish the wild turkeys around here were bigger but the hills are pretty lean pickings on this side of the valley.

[printhead]

Maybe the birds they couldn’t catch weigh more.

[BitWielder1]

Downsizing.

[a fool in paradise]

If you really want to understand some impact of man on birds (migration and bodyclocks), go to a large grocery store parking lot sometime at midnight. With all of the light noise, you will find hundreds of birds still awake chirping away.

Has nothing to do with “rising temperatures”, has to do with easier eating. Go where it is safe enough to not freeze.

I’ve also seen some odd waterfowl walking in neighborhoods at night (2 foot tall birds).

[lucky american]

People feed birds more than any wildlife out there. They are fat and happy.
I have birds that stay longer because the food is what they are after.

[cartan]

On average, the decline in mass of spring migrants over the 46 year study was just 1.3%," says Dr Buskirk.

"For a 10g warbler that's a loss of just 130mg."

But some species are losing more weight.

For example, the rose-breasted grosbeak has declined in mass by about 4%, while the Kentucky warbler has dropped 3.3% in weight and the scarlet tanager 2.3%.

Looks like academic standards are declining. This is well within error of measurement area. It's not only the social science faculties that are full of morons today. It is spreading. Idiocracy is approaching.

[F.J. Mitchell]

This has been a cold winter. Perhaps those hatched out this spring will grow larger and develope longer wing spans.

Or the smaller size of song birds could be caused by the condition of the world economy. Fewer people putting out wild bird food

Jail birds on the other hand seem to be getting much fatter.

[NavyCanDo]

My first question is who are we paying to study almost half a million birds?

[Between the Lines]

That suggests that bird species in North America are obeying Berman's rule, by evolving into a smaller size as temperatures increase.

Then why are people in the southern US so much fatter than people in the north?

[count-your-change]

Downsizing as the economy worsens isn’t unusual. Birds will just have to do their part!

[<1/1,000,000th%]

LOL!

[JOAT]

Clearly, the unwashed masses need to have their faith in Warmism restored.

Oh ye of little faith, the enlightened MSM shall carry the water for our beloved Patron Saint Algore.

[sodpoodle]

Based on 100 years of photographic evidence - it is very clear that (Western) humans have increased in volume. We are now enormous - up down and all around.

Humans live 70+ years. We changed in just four generations.

Birds live 2-5 years - Avian generational change has taken much longer. It may be cyclical - they get big & get smaller or cross breed or become extinct. Didn’t Darwin explain that?

[JWinNC]

"Maybe the birds they couldn’t catch weigh more."

ROTFL!

good one

[DBrow]

Hmm, global warming causes bias in balances used in the field!

Or, are the birds killed, then weighed, or captured, weighed in the field, or captured, brought to a lab then weighed?

a simple shift in protocols or in the precision and accuracy of the equipment could account for a 4% delta.

[Bulwyf]

Stop making any sense! Climate change is the reason we all don’t have our own unicorns and rainbows, please just go along with it and smile and nod like everyone else... lol

Ok, all sarcasism aside, how can the people who write this stuff be so blatantly stupid? Is there a course on how to be so mentally ill that you’ll state anything as fact?

[qwertypie]

Too funny. “Scientists” seeing things that they want to see.

[BJClinton]

In biology, there is a general rule of thumb that animals tend to become smaller in warmer climates

Then explain dinosaurs.

[dsrtsage]

Oh climate change, is there nothing you can’t do?

[sodpoodle]

****how can the people who write this stuff be so blatantly stupid?****

Mandated for tenure;)