From the UNIVERSITY OF BRITISH COLUMBIA and the “honey it shrunk the bugs” department, where correlation must be causation. Really, what else could it be but global warming? This reminds me of some other studies claiming some animal changed or vanished or was maligned by the dreaded warming, only to find out later, oh, never mind…
Warming climate shrinks British Columbia beetles
Some of B.C.’s beetles are shrinking as their habitats get warmer, according to new UBC research. The study provides evidence that climate change is affecting the size of organisms.
“In nature, there is so much going on that can affect body size so we weren’t sure we were going to see anything,” said Michelle Tseng, assistant professor of botany and zoology at UBC who oversaw the research. “This research provides evidence that climate change is affecting even the smallest organisms out there.”
Scientists expect living organisms to respond to climate change in three ways – by moving to new regions, changing the timing of their life stages or shrinking. To date, most of the evidence for organisms shrinking has come from laboratory work where the environment and living conditions can be tightly controlled. Tseng asked students in her fourth-year class to look into whether this is happening by examining beetle specimens in UBC’s Beaty Biodiversity Museum collection, as well as historical weather data.
Assisted by curators at the Beaty, students selected eight species of beetles from the Lower Mainland and Okanagan for their data set. They photographed more than 6,500 beetles and inputted information about each insect, when it was collected and where it was found into a database.
“We got data from 100 years of caught specimens,” said Sina Soleimani, one of the students who co-authored the paper and is now pursuing a doctor of pharmacy at UBC. “It’s cool that people have been collecting these insects since 1910 and noting all of their collection information. That’s probably what makes our paper stand out.”
The students measured whether the beetles had changed in size in the last 40 or 100 years. The students then used a climate database from the faculty of forestry to gather data about changes in the environment for the two regions where the beetles lived. They found that the Lower Mainland has seen a 1.6 C increase in autumn temperatures and the Okanagan has seen a 2.25 C increase in autumn temperatures over the last 45 years.
At first, the data didn’t indicate a clear trend – some beetles were shrinking, some were not. But by taking a closer look, they found that it was the larger beetles that were shrinking, while the smaller ones were not. The four largest species of beetles shrunk 20 per cent in the last 45 years.
“When these organisms were collected, I don’t think anyone ever thought that they were collecting them so we could monitor how they are changing,” said Tseng. “Museum collections contain more biodiversity now than will ever be collected again. It’s incredible that the diversity of collections in museums can help us understand and predict how organisms might change in the future.”
The students collected the data as part of their class assignment but to assemble all the information into one research paper took some extra work. Nine students continued to work on the project well after the class was over and they had graduated from UBC.
“This is my first paper that I’m publishing and it’s one-and-a-half years after the class ended,” said Katrina Kaur, who is now completing a master’s degree at the University of Toronto and returning to UBC in the new year to start a PhD. “It was a valuable experience as an undergraduate student. It was tough but I’m glad I stayed involved and saw it through.”
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The study was published today in the Journal of Animal Ecology: http://onlinelibrary.wiley.com/doi/10.1111/1365-2656.12789/full
Of course, one of the things these kids didn’t consider might be the fact that as the beetle collection grew, the collectors might be subconsciously selecting for capturing smaller beetles to save space.
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global warming causes shrinking …
Wrong wrong wrong.
cold causes shrinking. no study needed … doesn’t everybody know about shrinkage?
But, global warming may also cause centipedes to get bigger. Recent headline news in Hawaii is the capture of a record 14.5″ venomous centipede — nearly 3″ longer than the previous record. This is another illustration of Panic’s Law on Global Warming consequences: GW causes cute, friendly and beneficial organisms to become smaller, weaker and rarer while ugly, nasty and dangerous ones become bigger meaner and more common.
Story is here.
Anybody remember the joke about the biologist cutting off the frog’s legs one at a time and commanding them to jump? His conclusion, “Frogs with no legs are deaf”
This is study is right up there with that logic. There is not a word about competing explanations or steps taken to rule out confounding variables. The conclusion before they started was that any change in size they found was going to be due to temperature alone, apparently contradicting their opening paragraph.
LOL, that’s classic. And SO indicative of the state of “climate science.”
Perhaps the older collections skewed toward the largest specimens. That makes them easier to study.
A friend of mine ties flies of gnats, they make one of many trout foods. He has to use a microscope to see the bug and used another one to help tie the flies. They’re less than an 1/8in. long.
I took a fly fishing and fly tying class. Our tied flies were kind of ratty looking. The instructor passed around some professionally-tied flies. He said they were too beautiful and too expensive to get wet. One of the students asked if the fish could tell the difference. After the briefest of pauses, the instructor said, “No.”
Quoting the author’s “Discussion”: – “… maximum spring temperature … has decreased … last 45 years … overall decrease in beetle body size … suggests that increased temperature does NOT {{my capitalization for emphasis}} categorically result in smaller … sizes ….”
Previous section “Results” sub-heading 3.2.1 contains author’s quote: “.., 3 species … decreased in size, … 2 increased, … 3 did not change ….”
Then in “Results” sub-heading 3.2.2. author specifies ” … larger beetles … INCREASE {{my capitalization for emphasis}} in size per degree INCREASE {{my capitalization for emphadis}} spring temperature ….”
It seems to me any press release touting smaller bugs did not pay attention to the author’s specific findings.
This would seem to imply that there was not much, if any, increase in temperature in winter, spring and summer. This seems like a sure sign of a cherry pick.
Do these beetles only grow in autumn? I seem to recall that many insects hatch in the spring and grow to maturity pretty quickly. We see fully grown June Bugs around here in, ah … June.
I was a beetle collector myself for decades…..It is the following: Each beetle species produces individuals, which are different in size, up to 400%. You can go to any insect collector´s exhibition and you will see the Goliath or the Hercules beetle in sizes varying from small to very large. Now, a collector is proud of his large specimens and replaces by and by smaller specimens by larger, more impressive ones. I could, in my collectors time, only afford one small “Golden Beetle” from Indonesia, the large beetles stayed in the collection of the big guys. For this reason, older and more renowned collections have bought better and bigger specimens in size and color. Today, they dont seem to care and take all, second and third rate, all, small and medium, what has six legs and crawls.
For this reason, todays beetles are shrunk by global warming.
I learned that the partial pressure of oxygen determined the maximum size of insects. I guess that wasn’t settled science?
World’s largest beetles are found in the Amazon rain forest. Why not a colder climate?
According to Wikipedia, the world’s largest cockroach is in Australia (I guessed Penn State). Again, why would insects evolve to be so large in such a warm climate if global warming is supposed to drive shrinkage?
Largest insects of several types, according to Wikipedia, seem to be found Down Under, Indonesia, Papua New Guinea, New Zealand…why did they evolve to be so large while their cooler climate brethren are smaller?
Why the bugs are so big in New Zealand is simple: no mammalian predators. As a matter of fact most of the larger species have either gone extinct, become very rare or are only found on offshore islands since rats came to New Zealand.
The same possiby applies to some extent to Australia-New Guinea, marsupials seem to be less efficient predators than eutherian mammals.
Plenty of reptilian predators.
Lots of large insects in warm climates of Africa as well…no mammalian predators there, either, I presume?
I’m sure you can explain away this entire list then https://www.buzzfeed.com/mjs538/the-16-largest-insects-in-the-world?utm_term=.yxZzgoKzbB#.lsA6wyx6O8
I have been in BC for 50 years. I haven’t noticed that it’s getting warmer. The climate hasn’t changed. We still grow the same things and still can’t grow the same things that we couldn’t grow back then. Sure there is variability from year to year but it still pours rain for 9 months of the years, like it always has, and summers are hot and dry
The authors of the study seem to be blithely unaware that the test for significance becomes progressively more stringent as the number of comparisons to “climate variables” goes up. Eg in a Student T test this is proportional to the power of the number of comparisons (crossplots/regressions). Classic example of spurious correlation through regression of multiple variables. Regress enough variables and you will find “explanatory factors”.
OF course specimen selection by earlier collectors followed EXACTLY the same criteria used by current collectors, and there was NEVER any effort to ‘collect the biggest of the bugs’ of each species.
“Scientists expect living organisms to respond to climate change in three ways – by moving to new regions, changing the timing of their life stages or shrinking.”
When the planet greens up with more food for most organisms, along with mostly beneficial warming……………..shrinking but not the opposite?
The main shrinking that seems to be occurring is with regards to the objectivity in the brains of a large group of humans/scientists that do studies like this.
These beetles were the lucky ones. Many others were eaten as part of the World Food Substitutes Gathering at UC Davis and Berkeley.
Gotta vent on a pet peeve here. ‘To shrink,’ a regular verb: Shrink, shrank, shrunk. ‘Honey, I shrank the kids,’ fine. ‘Honey, I’ve shrunk the kids,’ also fine. ‘Honey, I shrunk the kids,’ no, wrong, stop it.
The insects shrunk? No they didn’t. They shrank. But have they shrunk? Yes.
Thank you for your attention. I’m done now.
Shrinking? No problem with that. I’ll only be worried if they become GIANT like the ones that used to be the subject of the movies shown as the “Creature Feature” on Saturday nights back when I was a kid.
Funny thing, one thing that I have noticed on my moderately extensive travels is that the warmer the climate, the bigger the bugs.
Even bugs of the same species are larger in warm climates than their relatives in more temperate and colder climates.
But there again, I’m not a “climate scientist”, so what would I know…