From the Imperial College of London , something buggy, though I have to wonder if other factors aren’t involved in the range expansion, like more sunlight getting through due to less aerosols/particulates thanks to pollution controls.
Light-colored butterflies and dragonflies thriving as European climate warms
Butterflies and dragonflies with lighter colours are out-competing darker-coloured insects in the face of climate change.
In a new study published in Nature Communications, scientists from Imperial College London, Philipps-University Marburg and University of Copenhagen have shown that as the climate warms across Europe, communities of butterflies and dragonflies consist of more lighter coloured species. Darker coloured species are retreating northwards to cooler areas, but lighter coloured species are also moving their geographical range north as Europe gets warmer.
For example, several Mediterranean dragonfly species have expanded their northern range and immigrated to Germany, such as the Southern Migrant Hawker (Aeshna affinis), the Scarlet Darter (Crocothemis erythraea) and the Dainty Damselfly (Coenagrion scitulum). In 2010, the Dainty Damselfly was also sighted in England for the first time in over 50 years. Butterfly species that thrive in warm climates, like the Southern Small White (Pieris mannii), have dispersed to Germany during the last ten years and are still continuing their northward shift.
As with lizards and snakes, the colour of an insect’s body plays a key role in how they absorb energy from the sun, and is crucial in fuelling their flight as well as regulating their body temperature.
Dark-coloured insects are able to absorb more sunlight than light-coloured insects, in order to increase their body temperature, and are more likely to be found in cooler climates. In contrast, insects in hotter climates need to protect themselves against overheating. Light-coloured insects are more likely to be found in hotter climates as they can reflect the light to prevent overheating their body and be active for longer periods of time.
Carsten Rahbek, from the Department of Life Sciences at Imperial College London said: “For two of the major groups of insects, we have now demonstrated a direct link between climate and insect colour, which impact their geographical distribution.”
“We now know that lighter-coloured butterflies and dragonflies are doing better in a warmer world, and we have also demonstrated that the effects of climate change on where species live are not something of the future, but that nature and its ecosystems are changing as we speak,” concluded Professor Rahbek, who is also Director of the Center for Macroecology, Evolution and Climate at the University of Copenhagen. To identify whether colour lightness was correlated to temperature, the scientists combined digital image analysis, which scanned and measured colour values of butterfly and dragonfly wings and bodies, with distributional data which mapped where in Europe the species are found.
They looked at 366 butterfly species and 107 dragonfly species across Europe, and showed a clear pattern of light-coloured insects dominating the warmer south of Europe and darker insects dominating the cooler north.
To test whether a warming climate had caused any shifts, they looked at changes in species distributions over an 18-year period from 1988-2006. Results showed that on average insects were becoming lighter in colour, and that darker-coloured insects were shifting towards the cooler areas in Western margins of Europe, the Alps and the Balkans.
Research has previously suggested that climate change is having an impact on the distribution of species, but this study provides evidence of a direct link and confirms basic assumptions about how changes in the climate can affect patterns of biodiversity.
Lead author Dirk Zeuss from Philipps-University Marburg in Germany said: “When studying biodiversity, we lack general rules about why certain species occur where they do. With this research we’ve been able to show that butterfly and dragonfly species across Europe are distributed according to their ability to regulate heat through their colour variation. Until now we could only watch the massive changes in the insect fauna during the last 20 years. Now we have an idea of what could be a strong cause of the changes.”
The paper:
Zeuss, D et al. 2014. ‘Global Warming favours light-coloured insects in Europe’. Nature Communications, 27 May 2014.
Under Strict Embargo – Tuesday 27 May 2014, 1600 BST / 1100 US Eastern Time
Once embargo has lifted, the paper can be downloaded at : http://dx.doi.org/10.1038/NCOMMS4874 Please note this is an uncorrected proof of the paper.
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“Darker coloured species are retreating northwards to cooler areas, but lighter coloured species are also moving their geographical range north as Europe gets warmer.”
Why are they “retreating” , I’d say they are taking advantage and expanding.
At least with a title like Nature Communications, we know they are not doing science. It’s “communication”. aka PR and propaganda.
Actually this has to be another classic of uncontrolled variables. This more like sociology , more “soft science” based of soft, malleable data.
That’s funny. I thought back fifty years ago they were showing that insects were trending toward darker colors as protective coloration due to the soot from pollution covering surfaces. Maybe with that cleared up thanks to scrubbers they are reverting to lighter colors.
Do we call this the butterfly effect?
Its payback time I guess. Back in the days of soot belching factory chimneys in the industrial north of Europe the tree trunks and buildings darkened leading to dark coloured moths and butterflies being better camoflaged from predators than their paler cousins. Now its the paler ones we are helping via our CO2 belching ways…poor butterflies don’t know whether to stick or twist. Our children may never see a dark coloured fluttery thing again. How do Dragonflies and butterflies handle wind turbines/solar farms I wonder?
Did they control for air quality? A major factor in color distribution is predation. So, for example, in Great Britain during the Industrial revolution dark colored insects thrived because they blended better into the sooty background. Now lighter colored insects are again more prevalent. Is the color shift a rebound from the Industrial revolution, much the way that temperatures are rebounding from the little Ice age?
So how much has Europe actually warmed in the past 18 years?
A few tenths of a degree makes that much difference?
This should cause a negative feedback then – light-coloured butterflies will radiate more sunlight back into space.
“but that nature and its ecosystems are changing as we speak,” concluded Professor Rahbek, who is also Director of the Center for Macroecology, Evolution and Climate at the University of Copenhagen. ”
It’s really amazing what science can reveal /sarc.
This is the sort of heifer dust that makes me wonder if anyone is doing real science anymore. They think it all has to be “warming” or lack of same. Can not be anything else! These are stupid people.
Soooo, the last 8 years or so of their sample period had no warming. What color did they change to during that time?
Next up, you can tell the temperature via the color of your butterfly. No thermometers required. /sarc
Reminds me of the Biblical Weather video!
Video redacted because I am being lazy today 🙂
Oh great…. Let’s spend $3.2 quadrillion (50-to-1 Project estimate) to make sure butterflies have the politically correct wing color…
Peer says :
“That’s funny. I thought back fifty years ago they were showing that insects were trending toward darker colors as protective coloration due to the soot from pollution covering surfaces.”
Actually, I believe it was first noted right after the industrial age provied for very sooty city surfaces (somewhat before and after the turn of the century in 1900) -it was noted that in a few short years, only moths whose color closely matched the soot covered tree trunks, etc, were still around. The lighter colored moths had been far too easily seen by predators when most surfaces became dark and sooty. This was used as an example proving Darwin’s selectivity theory.
Considering the effects of albedo (actually, more precisely, color) on the visibility of insects to their predators, there is obviously another independent variable at work here (There may be more that I can’t think of). This is a perfect example of the weakness of natural experiments, where the independent variables cannot be controlled. Any dependent variable change could have been the result of who knows how many independent variables.
This must be Gaia trying to maintain Earth’s temperature by increasing the albedo.
I remember that light/dark soot connection from a long time ago first in some childhood science book and later in many other sources. Nice to see so many people here remember it.
Bugs are not neutral. The want to hide or the want to be seen. A bug that that increases its relative albedo is happier being seen more easily. Finding mates has become harder -more shade or cloud – or less predation.
Warmer makes brighter fails the snifg test.
I read the paper before commenting. The species distribution finding seems robust. Darker species in cooler climes, lighter species in warmer climes. For both butterflies and dragon flies.
The climate change finding is a statistical joke on a par with Dessler’s positive cloud feedback finding in 2010. Fit an OLS trend through a shotgun pattern, find it goes up a tiny bit, and voila! Climate change. But the r2 ( not given) is close to zero. The result is essentially meaningless. As was Dessler’s, even before Steve Mac eviscerated the methodology used to concoct Dessler’s feeble result.
Shame that they took a major interesting finding about ectothermic species adaptation and had to pollute it with a garbagy climate change addendum.
is this like that study a few years ago that stated that warming in the SW US was causing a certain type of bush to move its range north? it turned out that this noteworthy move to escape the increasing heat what a whopping 150-200m
Wow, I had always thought something much different and now I realize how utterly, mind numbingly, stupid I was. I had always thought that brightly colored, and colorful, poisonous creatures such as wasps, bees, poison arrow frogs, Gila monsters, and the like, were colored that way as an instinctual warning to predators. And, that darker, bland colored creatures, that didn’t have the virtually unbeatable weapon of poison (or, the IRS), were colored that way so they wouldn’t advertise themselves as a potential meal. Thank god for tax funded climatology, and tax funded climatologists, I now know that it was really climate all along. Everything is about climate. Everything. And everything about climate is CO2. Everything.
I know this paper falls under the yawn category but has anyone read the methods section? Am I reading correctly that they compared digitally analyzed insects to illustrations of the insects in order to conjure up that a color change has taken place among all of these hundreds of species of insects?
More likely this is just a reverse of industrial melanism. The midlands of the UK and Central Europe are no longer sooty and dirty. No more dirty coal. No more blast furnaces. No more soot blackened brick buildings and smokestacks. That’s all in China now.
In every case, every case, changes in landscape, populations dynamics and natural cycles can explain the supposed climate change. There is a group of butterflies the Whites that are greatly affected by changes in agriculture and the weedy spread of plants in the mustard family. The cabbage butterfly was accidentally introduced into North America from Europe. There example of the “Southern Small White (Pieris mannii), have dispersed to Germany during the last ten years and are still continuing their northward shift” most likely can be explained by other factors.
Whenever a range changes in the past ecologists first asked what allows animals to disperse. Now that is never examined and papers spam the literature suggesting climate change magically moved them.
Birds chop what they can easily see I guess. That is the competition?
Here is the Peppered Moth? A moth that basically ‘evolved’ from patchy light and dark grey to ‘black’ due to England’s industrial revolution.
Robert Turner, they scanned actual species exemplars to color and grey scale code them. That gives a very precise estimate of ‘lighteness’ to darkness of Real bugs by species.