Claim: Amazon Rainforest birds’ bodies transform due to climate change

Peer-Reviewed Publication


Researcher Vitek Jirinec

The most pristine parts of the Amazon rainforest devoid of direct human contact are being impacted by human-induced climate change, according to new research by LSU scientists. New analyses of data collected over the past four decades show that not only has the number of sensitive resident birds throughout the Amazon rainforest declined, but the body size and wing length have changed for most studied species. These physical changes in the birds track increasingly hot and dry conditions in the dry season, from June to November.

“Even in the middle of this pristine Amazon rainforest, we are seeing the global effects of climate change caused by people, including us,” said Vitek Jirinec, LSU alumnus (Ph.D. ’21), associate ecologist at the Integral Ecology Research Center and lead author to this study published in the journal Science Advances.

Birds in the Amazon rainforest have become smaller and their wings have become longer over several generations, indicating a response to the shifting environmental conditions that may include new physiological or nutritional challenges.

This is the first study to discover these changes in non-migratory birds’ body size and shape, which eliminates other factors that may have influenced these physiological changes. Jirinec and colleagues studied data collected on more than 15,000 individual birds that were captured, measured, weighed, marked with a leg band and released, over 40 years of field work in the world’s largest rainforest. The data reveal that nearly all of the birds’ bodies have reduced in mass, or become lighter, since the 1980s. Most of the bird species lost on average about 2 percent of their body weight every decade. For an average bird species that weighed about 30 grams in the 1980s, the population now averages about 27.6 grams. How significant is this?

“These birds don’t vary that much in size. They are fairly fine-tuned, so when everyone in the population is a couple of grams smaller, it’s significant,” said co-author Philip Stouffer, who is the Lee F. Mason Professor in the LSU School of Renewable Natural Resources.

The data set covers a large range of the rainforest so the changes in the birds’ bodies and wings across communities are not tied to one specific site, which means that the phenomenon is pervasive.

“This is undoubtedly happening all over and probably not just with birds,” Stouffer said. “If you look out your window, and consider what you’re seeing out there, the conditions are not what they were 40 years ago and it’s very likely plants and animals are responding to those changes as well. We have this idea that the things we see are fixed in time, but if these birds aren’t fixed in time, that may not be true.”

The scientists investigated 77 species of rainforest birds that live from the cool, dark forest floor to the warmer, sunlit midstory. They discovered that the birds that reside in the highest section of the midstory and are the most exposed to heat and drier conditions, had the most dramatic change in body weight and wing size. These birds also tend to fly more than the birds that live on the forest floor. The idea is that these birds have adapted to a hotter, drier climate by reducing their wing loading therefore becoming more energy efficient in flight. Think of a fighter jet with a heavy body and short wings that requires a lot of energy to fly fast compared to a glider plane with a slim body and long wings that can soar with less energy. If a bird has a higher wing loading, it needs to flap its wings faster to stay aloft, which requires more energy and produces more metabolic heat. Reducing body weight and increasing wing length leads to more efficient resource use while also keeping cooler in a warming climate.

LSU alumnus Ryan Burner (Ph.D. ’19) conducted much of the analysis that revealed the variation among the groups of birds over the years. Burner, who is now a research wildlife biologist at the U.S. Geological Survey Upper Midwest Environmental Sciences Center, is the second author of this study.

The question of the future capacity of Amazonian birds to deal with increasingly hotter and drier surroundings, especially in the dry season, remains unanswered. The same question can be asked for a lot of places and species that live at the edges of even more environmental extremes.

“There may be other researchers in other places who have relevant data from the 1970s and 1980s that could be compared to modern data, because the bird banding protocol we used is pretty standard. So if you measure mass and wing, maybe there will be more datasets that will emerge and we’ll be able to get more of an idea of the variation across space and how it might be changing in different systems,” Stouffer said.


Science Advances






Morphological consequences in climate change for resident birds in intact Amazonian rainforest



From EurekAlert!

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November 13, 2021 2:23 am

There is no climate change in Amazonia. What there is, is logging.

Joseph Zorzin
Reply to  Chaswarnertoo
November 13, 2021 3:23 am

If it were just logging as part of long term forest mgt., it wouldn’t be a bad thing- but it’s better described as land clearing.

Thomas Gasloli
Reply to  Chaswarnertoo
November 13, 2021 7:55 am

And genetic drift. Every change is not an environment induced change.

Reply to  Thomas Gasloli
November 13, 2021 9:01 am

What do you expect from Eurk Alert. Their confusion between evolution and imaginary climate change is a result of the same ignorance that leads to the rest of the nonsense they attribute to CO2 emissions.

Reply to  co2isnotevil
November 13, 2021 12:16 pm

That they contribute to emissions, not limited to CO2… the green molecule, and C the green atom.

Jeffery P
Reply to  Chaswarnertoo
November 13, 2021 10:14 am

Now there’s the rub — deforestation can and does cause local climate change. Logging is human activity, therefore there is man-made climate change in the Amazon. But switching to electric cars and building windmills has nothing to do with it.

Paul of Alexandria
Reply to  Jeffery P
November 14, 2021 11:37 am

All of that area used to be cleared a thousand years ago. I wonder if Inca land clearing caused the Middle Agrs warming?

Reply to  Chaswarnertoo
November 13, 2021 10:58 am

There is also a highly variable insect population of about 10:1 annually, mosquitoes for example, whose population depends on rain puddles occurring at just the right time…which could easily trend bird weights down or up a couple of grams.

Reply to  DMacKenzie
November 13, 2021 12:16 pm

Diet is destiny.

Reply to  DMacKenzie
November 13, 2021 1:52 pm

How is it that your comment makes sense?

Reply to  DMacKenzie
November 13, 2021 3:52 pm

birds don’t evolve that fast…..this is total BS

Reply to  Latitude
November 13, 2021 7:56 pm

Depends on what you mean by “evolve.” Some gulls will generate an organ to rid themselves of salt when their blood salinity gets too high. The organ will disappear if they start feeding in freshwater. Not Darwinian evolution, for sure, but obviously preprogrammed to help them adapt.

Reply to  Latitude
November 14, 2021 3:49 am

Methinks a certain Mr Charles Darwin (and many others since) has proof to the contrary my friend.
Search for changes to beak lengths in Finches etc and see how short term changes have continuously been identified and reported upon.
Birds (some types) do (appear to) evolve (change) over short time scales

Reply to  jono1066
November 15, 2021 9:28 am

Yes, some organisms can have amazing changes.

I don’t know if any of you have heard of this, but it is very amazing.
We all are familiar with caterpillars. Right?
In Amazonia, they actually undergo this bizarre change. Each at some point makes what you might call a “cocoon,” and hiernates for a while. In the cocoon, the caterpillar transforms itself into something like a moth, but ten times more beautiful. Brightly colored wings, etc.

They call this a “butterfly.” I know this sounds crazy. But google “butterfly,” and you can see examples. Also, there are also videos where this change has been captured on film.

This puts that “evolution” story of the white moths and dark moths to shame, not to mention Darwin’s finches with their beak length.

I don’t want to post too long, but another one to check out: tadpole.

Reply to  Chaswarnertoo
November 13, 2021 12:13 pm

Smaller bodies, longer wings, would aid gliding.

Mike Dubrasich
Reply to  Chaswarnertoo
November 13, 2021 4:03 pm

The wet-tropical forest is pretty much unchanged since the Cretaceous. Logging doesn’t change the climate or the weather. Birds don’t evolve on a year-to-year time scale. Neither the climate nor the bird weights have been measured with anything approaching skill or accuracy.

What is evident is that bird biologists are mist-netting birds, manhandling and torturing them, and calling such “science” when it is more like Medieval animal sacrifice.

Reply to  Mike Dubrasich
November 13, 2021 7:57 pm

See my comment above. Darwinian evolution it ain’t.

Tom Halla
November 13, 2021 2:25 am

Meta-analysis? As no new research was done, was any statistical measure made to determine that the decline was real?

Reply to  Tom Halla
November 13, 2021 4:41 am

Not necessary in postmodern science .
A few month ago some lunatics were able to determine that dragonfly wing patterns were changing faster than ever before – as result of climate change.
An interesting claim about a 200 mio year old species that can be found in the hottest and coldest regions on earth.
They didn’t mind to explain how they got enough fossiles for any existing 35 year period prior to the AGW scam to validate the claim
or the fact that it simply impossible to determine the exact age of old fossiles,and the older the fossiles are the bigger the margin of error.

Reply to  SxyxS
November 13, 2021 12:19 pm

This is modern science: radical, divergent, post-normal.

Reply to  Tom Halla
November 13, 2021 6:58 am

Certainly animals physically adapt to their changing environment, but I’d wager that it’s easier to catch less mature birds that haven’t yet figured out how to evade their capture by scientists. Animals also adapt by learning and adapt their behavior to impart some advantage. Avoiding capture would be a learned behavior that reduces harm to them.

Trying to Play Nice
Reply to  Tom Halla
November 13, 2021 7:03 am

I think their meta-analysis was reading Facebook posts.

Pamela Matlack-Klein
Reply to  Tom Halla
November 14, 2021 1:01 am

Are these people assuming that all birds of a species are identical and any differences between individuals must therefore be due to climate change?

November 13, 2021 2:26 am

Climate change is effecting us all they say- According to the word obesity federation the world is getting fatter and is happening in every country- who would have thought.

Thomas Gasloli
Reply to  richard
November 13, 2021 7:57 am

The birds get smaller; the humans get fatter. All due to that magic compound CO2.😱

Jeffery P
Reply to  Thomas Gasloli
November 13, 2021 10:16 am

I say we should lock-up all that carbon contained in our bloated, obese corpses. The Fremen recover the water from their dead, why can’t we recover or sequester the carbon in ours?

November 13, 2021 2:27 am

Global warming forgotten, climate change arise, CO2 devil incarnate. Just keep repeating he mantra.
Whole thing is a bit like an ‘modern’ opera called Einstein on the beach, in which there is no Einstein and there is no beach.

Just keep repeating mantra.

What if there is no global warming and CO2 is not a devil but a life giving angel.

Reply to  Vuk
November 13, 2021 7:05 am

If that segment is indicative of the play as a whole, I would be looking for the exit to the gas chambers.

Gregory Woods
November 13, 2021 2:32 am

Not being a Bird Man but this all sounds like pidgeon crap to me…

November 13, 2021 2:40 am

Lucky we have the increased levels of CO2 to help new growth replace some of the losses seen through logging and land clearing

November 13, 2021 2:45 am


Joao Martins
November 13, 2021 2:47 am

Amazon Rainforest birds’ bodies transform due to climate change

Is there a rain forest in or near Seattle? … Or is this plain BS?

November 13, 2021 2:58 am

“If you look out your window, and consider what you’re seeing out there,”

The usual for November

The pigeons etc are doing well and so are the non native parakeets

There is no cause for alarm

Reply to  fretslider
November 13, 2021 4:17 am

Here in the UK some of the trees still have green leaves, the grass is still growing, there is the occasional flower, still just the one light frost.

not at all like mid November last century

Ed Zuiderwijk
Reply to  griff
November 13, 2021 4:29 am

All it takes is a good old-fashioned November storm. But when it comes, I bet you, it will be attributed to climate change.

Reply to  griff
November 13, 2021 4:34 am

Thankfully that’s a great improvement on 1821 & 1921,

Reply to  griff
November 13, 2021 5:06 am

Griff there are many species of plant that flower at this time of year – eg hedge bindweed

Here in the UK it is a bog standard November

Reply to  griff
November 13, 2021 5:26 am

You should come to the USA Griff. Here, there has been no change in surface temperature ever since we started measuring it carefully about 17 years ago. See

Rich Davis
Reply to  DHR
November 13, 2021 9:12 am

“You should come to the USA Griff”

We have more than enough useless parasites here already. UK is stuck wi ‘im.

Reply to  Rich Davis
November 14, 2021 5:46 am

Ok. We already have Harry.

Climate believer
Reply to  griff
November 13, 2021 5:48 am

“not at all like mid November last century”

Like for example the very warm November of 1906, when 20°C was recorded in Lairg Scotland. Lairg is 50 miles north of Inverness.

…or November 1938 when 21.1°C was recorded in East Anglia.

… or maybe you’re thinking of the 21.7°C recorded in North Wales in November 1946.

What about November 2010, do you remember Grifter?

Northern Ireland hit a low of -9.5C (15F) at Lough Fea, Co Tyrone, and in Wales, a record minimum of -18C (0F) was reached at Llysdinam, in Powys.
In England, the coldest spot was Topcliffe, North Yorkshire, where the mercury fell to -13.5 °C (8F).

It’s called weather, it varies.

Right-Handed Shark
Reply to  griff
November 13, 2021 6:06 am

Strange that there were so many stories in August that the leaves were dropping early this year.. hmmm, now what were they blaming that on?.

Reply to  griff
November 13, 2021 7:05 am

Here in the UK some of the trees still have green leaves

Well slap my ass and call me Sally, Griff has discovered evergreen trees

Griff, mate, grass grows in temperatures above 5C regardless of the season. It’s not unusual for grass to grow in November when the average temperature is above 5C

Reply to  griff
November 13, 2021 7:20 am

It’s all those extra stools floating in your rivers and oceans

Teddy Lee
Reply to  LdB
November 13, 2021 8:43 am

Apparently the CEO of the offending water company, in mitigation said that the discharge included some “clear looking water”

Teddy Lee
Reply to  griff
November 13, 2021 8:37 am

Here in Cambridge UK we have had twice as many frosts as you. A few deciduous trees still have some green leaves.Many have a mixture of autumnal colours and bare branches.
There, fixed it for you.

Rory Forbes
Reply to  griff
November 13, 2021 1:27 pm

Still confused about weather vs. climate and natural seasonal variation, I see. You Brits really are easily indoctrinated apparently. You seem to have completely fallen for AGW dogma.

Richard Page
Reply to  Rory Forbes
November 13, 2021 4:27 pm

Not all Brits, just the ones like Griffy.

Rory Forbes
Reply to  Richard Page
November 13, 2021 4:41 pm

Canada has only been pushing “climate change” propaganda since Trudeau got into office. The UK has been officially promoting this insanity for at least two decades. The BBC has a mandatory editorial policy to include a false narrative into ALL programming. That constitutes state mandated indoctrination. Orwell appears to have had a similar view to my own.

You guys need to be careful because you might just look up and fail to recognize your own country. Britain’s soil seems to be far too fertile for the Left.

John in Oz
Reply to  griff
November 13, 2021 2:27 pm

I read your comment while sitting in my cold room (currently 8C with an expected high of 14C) in ‘the driest state on the driest continent – South Australia’ listening to the rain and wondering if it is really only 2 weeks before Summer is due to arrive.

Having recently suffered the coldest November day in 30 odd years, a pox on your CAGW beliefs.

Rory Forbes
Reply to  John in Oz
November 13, 2021 4:30 pm

I believe Antarctica is the driest continent.

Matthew Sykes
Reply to  griff
November 15, 2021 12:03 am

Frost around Haloween (we actually had two in Devon, and we are warm and wet down here, there has been snow up north) is normal.

But it has been a mild november, and not that windy, the leaves are hanging on longer. That doesnt mean there is a climate crisis though Griff. The weather is the same as it was, and so is the climate. It is still a temperate zone.

Reply to  fretslider
November 13, 2021 7:11 am

It’s warm and windy today in Colorado.

I don’t see any birds right now but squirrels are gathering samaras from the maples. Interestingly, my large oak tree doesn’t have any acorns this year and last year it produced gobs. Must be global warming.

Rich Davis
Reply to  Scissor
November 13, 2021 9:19 am

Unvaccinated oak trees are 11 times more likely to have no acorns than vaccinated oak trees.

Reply to  Rich Davis
November 13, 2021 2:00 pm


Reply to  Scissor
November 13, 2021 3:34 pm

Don’t know if this is true, but someone told me that oak trees produce gobs of acorns before a cold winter, so therefore less acorns if a warmer one.
Let us know how this winter compares to last winter.

Mike Dubrasich
Reply to  chickenhawk
November 13, 2021 3:54 pm

How do oak trees know the future? Are they psychic? Do they models?

Reply to  Mike Dubrasich
November 13, 2021 6:36 pm

You are partly right. You’re probably familiar with the Quercus virginiana, but the related Quercus kreskiniana is the one they were talking about.

Mike Dubrasich
Reply to  chickenhawk
November 15, 2021 8:10 pm

Oh, the voodoo oak. Why didn’t you say so? Portends the future through its magical stomata. Maybe weather forecasters should divine next year’s Winter by sticking acorns up their … noses.

Pamela Matlack-Klein
Reply to  chickenhawk
November 14, 2021 1:11 am

Acorns and other mast tend to alternate, heavy cropping one year, lighter the next. It has more to do with soil fertility than weather and nothing to do with climate!

Reply to  Pamela Matlack-Klein
November 14, 2021 7:25 am

I was merely repeating something I heard. I would be interested in actual measurements though. Acorn yield with temps; over time with many trees before dismissing. Perhaps a connection from the spring weather or previous winter, such as Joe Bastardi’s “cold May/cold December” observation.

Still agree with most, probably not a real thing.

One question Pamela, how does soil fertility change from one year to the next? It would seem that an undisturbed forest oak would have soil that didn’t change from year to year.

Pamela Matlack-Klein
Reply to  chickenhawk
November 14, 2021 11:47 am

The fertility of the soil does not change from year to year but because it is low the tree can only get enough nourishment to produce a large crop every other year. When orchards are fed sufficiently, with attention to micronutrients also, they can crop heavy annually. Pretty sure I have this right, but if I am in error, I will hear about it. I am recently learning a lot about poor soils and how to upgrade them.

Reply to  Scissor
November 13, 2021 8:01 pm

Maybe 2020 was a mast year?

Jeffery P
Reply to  fretslider
November 13, 2021 10:18 am

Looking out the window, I see the sea gulls have migrated south from the Great Lakes. So yeah, winter is coming.

Ed Zuiderwijk
November 13, 2021 3:01 am

They seek it here, they seek it there, those climate clowns seek it everywhere.

November 13, 2021 3:07 am

Sounds like they are adapting to being banded and harassed.

Reply to  Gator
November 13, 2021 7:17 am

I use a live trap occasionally to catch rabbits to remove them from my yard, and I relocate them. This year, due to climate change I presume, there hasn’t been a rabbit in my yard for months.

Reply to  Scissor
November 13, 2021 2:13 pm

Right, but that climate change only happens every (inferred..10 yrs.).

Note: the 10-yr. “cycle” is not set in concrete.

Ron Long
November 13, 2021 3:48 am

So Burner PhD 2019) is a wildlife research biologist with the US GEOLOGICAL Survey? Can we guess CAGW Activist on a mission? Can we agree that the once respected US Geological Survey has been corrupted into a Political entity?

Reply to  Ron Long
November 13, 2021 4:20 am

It hasn’t has it?

It carried on exactly as before climate change became apparent and in its usual operations it observed the facts of climate change.

If you have to assert that the USGS, NASA, the Royal Society, British Antarctic Survey, the UK Met Office and the world’s oldest universities have all been taken over by communists/sinister forces/people just in it for the climate money to give credence to your views, well I think you lost the argument.

Climate believer
Reply to  griff
November 13, 2021 4:49 am

When Orwell wrote “Ignorance is strength” he didn’t mean you to take it literally.

Right-Handed Shark
Reply to  griff
November 13, 2021 6:29 am

You mean the same British Antarctic Survey that is well aware of geothermal processes beneath Thwaites Glacier:

and contributed to this piece of BBC propaganda?

George Daddis
Reply to  griff
November 13, 2021 6:56 am

They are in it for their jobs, which is essentially the same thing.

Remember the line from one of Upton Sinclair’s novels”
“It is difficult to get a man to understand something, when his salary depends on his not understanding it.”

Teddy Lee
Reply to  griff
November 13, 2021 8:44 am

So you knew all the time. Sly old goat.

Richard Page
Reply to  Teddy Lee
November 13, 2021 4:29 pm


Reply to  griff
November 13, 2021 12:19 pm

These institutions you quote don’t produce anything useful for anyone

Rory Forbes
Reply to  griff
November 13, 2021 1:40 pm

All you’ve shown is that these institutions are all heavily politicized and that neither consensus nor appeal to authority and appeal to numbers have anything to do with science. Herd immunity is a good thing, whereas herd mentality is not.

John in Oz
Reply to  griff
November 13, 2021 2:32 pm

before climate change became apparent

Among your many ignorant statements, this one is a doozy.

Do you really believe that it is only recently that climates change or that no-one noticed it in the past?

You should read more history books for a broader knowledge base prior to making such inane remarks

Reply to  griff
November 13, 2021 3:37 pm

“… assert that the USGS, NASA, the Royal Society, British Antarctic Survey, the UK Met Office and the world’s oldest universities have all been taken over by communists/sinister forces/people just in it for the climate money …”

By Jove man, I think you’ve got it!

Ron Long
Reply to  griff
November 13, 2021 5:55 pm

griff, I actually interacted with the regular USGS, they did really good geology, to include producing geology maps which I utilized to good effect. The Australian CSIRO and the Argentina CONICET, both of which I have interacted, have also morphed into advancing Political Science.

Paul of Alexandria
Reply to  griff
November 14, 2021 11:43 am

Actually… go look up the Frankfurt School, Critical Theory, and their “long march” through the institutions.

Geoff Sherrington
November 13, 2021 4:02 am

Re birds flying like aircraft, the second author can be quoted on a remedy, as in After Burner.
Geoff S

November 13, 2021 4:47 am

Thank you, climate change people, for killing Darwin and evolution. You did what courts could not do–wipe out an accepted theory for monetary gain. Way to go.

Reply to  Sheri
November 13, 2021 7:20 am

There are 50+ genders. Science today.

Reply to  Scissor
November 13, 2021 7:31 am

I work with government data systems. Our current data bases have a single byte for the gender field. We are working on a request for change to make this a two byte field.
This is a simple change, but not a small one. The records that we receive have to be modified to show two bytes instead of one. Every piece of code that references gender, (there are hundreds of these) have to be modified to accept 2 bytes. Every report that includes gender will have to be modified. We are talking hundreds of hours worth of work.

Jeffery P
Reply to  Scissor
November 13, 2021 10:20 am

My prefer pronouns are “your majesty” and “her royal highness.”

Did I insult someone? Good. Ridicule is the best way to expose the ridiculous.

Peta of Newark
November 13, 2021 5:14 am

We are in so much trouble here – on two counts:

  1. That a rainforest has ‘dry seasons
  2. That folks who should know better, actually think ‘dry seasons‘ are the norm
Reply to  Peta of Newark
November 13, 2021 7:13 am

Peta, the Amazon rain forest “dry season” is between June and December. It just means there’s less rain than in the wet season

Jan de Jong
November 13, 2021 5:23 am

Science Advances? Don’t think so.

November 13, 2021 5:49 am

 human-induced climate change” No need to bother reading past that crap right there, no science involved, nothing but politically driven stupidity.

Jeffery P
Reply to  2hotel9
November 13, 2021 10:23 am

If the deforestation is because of logging or clear-cutting, yep, that’s human-induced. But it has nothing to do with fossil fuels and just because some climate change is human-induced does mean it all is.

Reply to  Jeffery P
November 13, 2021 10:34 am

Environmental damage and climate change are two entirely different things. Humans can damage environment and can “fix” it. Climate changes, always has and always will. Humans are not causing it and can not stop it. That last point bears repeating, “and can not stop it”. We are watching our energy production, manufacturing and agriculture systems being destroyed based on lies.

Reply to  2hotel9
November 13, 2021 3:01 pm

There we are with the “bears” again.

Reply to  sturmudgeon
November 14, 2021 3:08 am

Damn bears, always scattering the trash!

Reply to  Jeffery P
November 13, 2021 3:00 pm

presume you meant “does not mean it all is”.. ?

Andy Espersen
November 13, 2021 6:14 am

So, what??

November 13, 2021 6:43 am


November 13, 2021 7:22 am

Apparently evolution stopped in 1970, and nobody told me.

November 13, 2021 7:47 am

The reported “loss” in average weight of these hand-sized and larger birds is 2.4 grams –a U.S. penny (1 cent coin) weighs 2.5 grams. Even if the reported difference isn’t accountable to changes in measurement equipment and techniques over the 40 year period, it is small at 2%.

Having a single numerical value for “Amazon Birds” is a bit odd.

It would not even be a clinically significant change it it were weight loss in a single bird between seasons.

For a 150 lb. human, 2% weight loss would be 3 lbs.

Note that if the report is true (all the facts are correctly measured, recorded and reported), it signals an evolutionary change — a small downward shift in weight and a lengthening of wings. These types of changes are down to selective mating — not climate change. Of course, modern biology suffers multiple personality disorder in regards to Darwinist evolution.

David Pentland
Reply to  Kip Hansen
November 13, 2021 11:20 am

I believe that the climate is changing, I believe the birds are adapting. This isn’t new. It was Darwin’s famous observation on the Galapagos after all.

How cotradictory to believe we have the power to measure, predict and control “Global climate change”, but not the natural abilitity to adapt, like the birds.

Rory Forbes
Reply to  David Pentland
November 13, 2021 1:50 pm

It is true that all climates are changing. It is not true that all climates are changing at the same rate. Change is the default condition of this planet’s various climates. It is not true that we can think of this planet as having a climate of its own. In other words there is no such thing as “global climate change”. The idea is an absurdity. There are locations where the “climate” hasn’t varied in a human lifetime.

Reply to  Rory Forbes
November 13, 2021 3:05 pm

This, along with many other Common Sense statements/comments shown here, SHOULD NOT HAVE TO EVEN BE STATED!

Rory Forbes
Reply to  sturmudgeon
November 13, 2021 4:24 pm

I repeat this at regular intervals as a matter fact, merely to remind people that we must all use the proper terminology in the correct way. When we begin using the language provided by the “enemy”, Orwell’s warnings are accelerated. The Left continue to gain ground the more we demure to their use of words. We’ve allowed them to replace sex with gender, destroy the meaning of ‘gay’, conflate tolerance with acceptance, invent new pronouns, “reimagine” human rights and even the null hypothesis … and on and on.

The term “climate change” has no real meaning, as it is being used, it’s an appeal to ambiguity (equivocation). If we don’t take back the language we’ll lose the fight completely because the true believers are progressives dictating the rules of a conservative discipline.

Reply to  David Pentland
November 15, 2021 9:46 am

David ==> “The” climate change for the birds in this study is limited to LOCAL changes, if any. Probably many locales, as the Amazon is not single climatic unit but has many variable climates inside its political/geological borders.

The local climate for a particular bird may have changed – it may be warmer/cooler on average, it may be wetter or dryer on average, sunnier or cloudier on average, but this is doubtfully an evolutionary force on the scales known for these climate features for the area.

It would take a Rudyard Kipling-esque imagination some time to makeup a Just So story for how minute changes in rainfall or an increase of 1 degree of temperature would cause a whole class of the animal kingdom — Amazonian birds — to lose a very small amount of overall weight and grow minutely longer wings.

If the measure/computed change it real — which is questionable — there is still no evidence whatever to lay it to the account of changing climate (if the climate has changed locally).

You may need to re-read Darwin on the Galapagos. He didn’t find birds changing — he just found birds different than elsewhere — confirming that isolated breeding populations are prone to accelerated genetic morphological drift.

Charles Higley
November 13, 2021 8:36 am

Too many variables here to even shake a stick at. Smaller birds more likely suggests competition for food. And longer wing length is favored to get to the limited food. Yeah, it must be climate change. And competition for food might indicate either a lack of food or increase in competitive abundance. All of that has to be taken into consideration.

When a bird flu killed a large proportion of herring gulls on the Eastern seaboard, the next generation of gulls were huge, monsters, compared to their parents, as there was so little competition for food.

The tropical rainforests and coral reefs are the two most stable ecosystems on the planet as they are always present, even during glacial periods. It is through their long-term stability that they have been able to evolve the incredibly complex ecosystems that they have today. They are not endangered in any way. For that matter, there is more rainforest today in the Amazon than there was in 1950. It is only in places like Sumatra, where they have been cutting down forests for palm plantations and renewable oils, that the rainforests are in danger.

The endangered ecosystems are the simpler ones that are more toward the poles. Such simple systems are much more easily affected and are also subject to glacial periods. Canada will be completely wiped out in the next glacial period. What they do up there is of no consequence and the ecosystem components of that region will have to move toward the equator or die.

Yes, there is a dry season in the rainforests, but I question how the dry season has been studied, or have they relied on the biased and improper temperature records?

They might have detected these changes in the birds, but that only reflects how they are flexible and adaptable in the face of ecological changes. This is not a problem, as we know it was warmer during the Medieval Warm Period and even warmer during all previous Periods back to the Holocene Optimum. Of course, the fact that we are cooling presently will not prevent them from assuming warming effects, as that is what they are paid to do.

Climate believer
Reply to  Charles Higley
November 13, 2021 10:33 am

“Too many variables here to even shake a stick at”

Yes I agree, a couple of them he brought up in the study, for example; changing age ratios, where all three morphological metrics were lower in juveniles, or, nutritional strain where bird condition fell in stressful years with lower food availability.

He is nonetheless adamant that it’s all down to changes in temperature and precipitation, which as far as I can see, over the study period, are miniscule compared to daily and seasonal variations which are far more extreme, and have been for thousands of years.

November 13, 2021 8:52 am

The Amazon does not have a “dry” season. Its rainfall varies from lots to less than lots but never none. Animal size normally varies with diet both in amount and type. Changes in the availability of bird food in the area observed can cause changes in body size. Did the researchers research this and if so, what are the likely reasons for any observed changes? What measures of “climate change” are thought to be responsible. Wind, temperature, humidity, sunlight, and many more are included within this catchall. To find a change and then blame in on an unspecified “climate change” is simply poor science.

Rory Forbes
Reply to  DHR
November 13, 2021 1:56 pm

Of even greater importance is the fact that this planet does not have a “global” climate. It is a coupled, non-linear chaotic system composed of numerous separate climates. The Amazon is a tropical rain-forest climate. It may or may not have had any measurable change at all, during the observed period.

November 13, 2021 9:16 am

OK. They claim that Amazonian birds do not differ in size much, and that a 2% change is somehow significant. Pictured in their article is a Amazonian Motmot, and according to the interwebs, this bird can weigh between 100 and 145 grams. That is a much larger change than 2%. I cannot imagine that climate hucksters would mislead us, but this is more than a little puzzling.

Rory Forbes
Reply to  Gator
November 13, 2021 2:01 pm

We must accept, if their “science” is to believed at all, that the weight range is now between 98 and 142 grams … and an even bigger stretch is that their sampling has been so precise they were able to determine it.

Jeffery P
November 13, 2021 10:12 am

On the one hand, of course living things change when their climate changes. It’s called adaptation.

But none of this provdes the climate change is caused by human green house gas emissions. There are many causes of climate change and many are in play at the same time. So on the other hand, bull!

How is it science recognizes adaption as natural but don’t understand humans can also adapt? Why do they seem to believe the citizens of Manhatten will one day wake up to find the lower floors of their buildings are under water? Won’t the people adapt by building dykes, levies and sea walls?

BTW — this is how humans adapt. We don’t have to wait for natural selection to evolve. Our culture (which includes engineering and technology) evolves far more rapidly.

Rory Forbes
Reply to  Jeffery P
November 13, 2021 2:04 pm

Even more noteworthy is how they were able to provide such detail without explaining exactly how that specific climate (tropical rain-forest) was altered by man. They expect us to accept generalizations of generalizations as some sort of parameter for measurement.

Reply to  Jeffery P
November 13, 2021 3:48 pm

When humans are finally able to create the types of things you dream about, such as dykes, levies and sea walls, then they will finally devise a way to create machines small enough to fit in windows that can magically transform warm air into cool air.

November 13, 2021 12:10 pm

Dietary changes? Did they check the sex (i.e. male, female)?

M Courtney
November 13, 2021 12:44 pm

Journal ‘Science Advances’ discovers evolution.
It seems science does advance but, in that journal, very slowly.

Peter Plail
November 13, 2021 1:48 pm

If they have lived a life devoid of human contact did they take their own measurements and mail them in?

November 13, 2021 2:31 pm

Why the push to find fault? It is a disservice to WUWT to kneejerk reject new input.
This seems a fairly careful study, way over 10,000 specimens measured over 40 years, with a general downtrend in weight of about 2%/decade.
That seems a noteworthy finding, with no obvious explanation.
Climate change may be a candidate, although I’ve no idea whether the claim of an ‘increasingly hot and dry’ dry season is valid. Does anyone have actual data on this?
Logging and human encroachment may well be factors as well, it would be interesting to see both historic as well as current maps of the areas studied, to verify that these are ‘pristine areas’.

Reply to  etudiant
November 13, 2021 3:13 pm

That seems a noteworthy finding, with no obvious explanation.” The “fault-finding” is likely induced by reading your last four words in your opening question.

November 13, 2021 7:20 pm

There’s a book that discusses much the same topic, titled “The Beak of the Finch”, by Jonathan Weiner, (1994), which describes different species of Galapagos Island finches, and their changing distributions during years with wet and dry periods.

Darwin had famously noted that the beaks of these birds varied according to the foods they ate. The researchers wanted to see how the proportions of the finch population changed under varying climate conditions. Sure enough, after several dry seasons the birds which ate things unaffected by drought thrived, while those who relied on food sources requiring more water, declined. When conditions changed, so did the relative proportions of the finch population.

It’s kind of a no-brainer. If logging and land-clearing are changing the habitat of Amazonian birds, one would expect them to undergo a similar process. But that’s a far cry from saying humans are causing those birds to “evolve” due to changes in atmospheric CO2. If conditions change so much that the birds fail to adapt, they could just as easily go extinct–as the Passenger Pigeon did. (they were tasty, and flew in enormous flocks that made them VERY easy to hunt).

Reply to  Effinayright
November 13, 2021 8:09 pm

But it turns out that, while finch beaks do vary with conditions, they remain finches capable of breeding with other finches. Variation within limits, not on the road to macroevolution. Once again, neo-Darwinism explains survival of the fittest, but not arrival of the fittest.

4E Douglas
November 14, 2021 8:10 am

How about land clearing due to Biofuel plantations ? Yep, climate change…

November 14, 2021 1:10 pm

I didn’t know birds could sense and respond genetically within 30 years to 0.57 C degree change.

Andre Thomas Lewis
November 14, 2021 4:13 pm

Just one more piece of research, done with integrity initially, that found to get published and read a mention of climate change being involved was necessary.

chris norman
November 14, 2021 5:22 pm

The same nonesense is being broadcast in Australia.
In NZ the dsifference in Temp between Southland and Nortland is Approximately 4 and 6 degrees C. There is no meaningful difference between bird populations.

Matthew Sykes
November 15, 2021 12:00 am

A smaller body need smaller wings, so why longer?

I have to wonder whether they have junk data, ie used a sub population with random variation, because apart from increased CO2, the tropics aren’t impacted by its warming because they are so humid.

I did however check the raw data from GISS website for a number of Amazon stations, and there does seem to have been some warming post 2000.

And even if this change in the birds body is real, what is the mechanism, the reason for it, why would warming promote such an e4volutionary change?

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