The annular ant (Corythopis torquatus) was among the 77 species examined in the recent study.
Majority World / Universal Images Group via Getty
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Majority World / Universal Images Group via Getty
The annular ant (Corythopis torquatus) was among the 77 species examined in the recent study.
Majority World / Universal Images Group via Getty
Scientists have discovered something strange has happened among susceptible birds in the Brazilian Amazon in recent years.
The birds not only decreased in number but their bodies also shrunk in size.
“We found that size not only shrinks for susceptible species, but decreases for everyone,” said Louisiana State University researcher Vitek Jirinec.
Jirinec’s findings are in a new study published in the journal Science Advances Last Friday.
It was enough to set off alarm bells for Jirinec’s supervisor, Philip Stouffer.
“What impressed me most about this place was that it was in the middle of the most intact rainforest in the world,” says Stouffer.
The study examined 77 species over a 40-year period, during which time rainforests became warmer. It found they were growing rapidly – perhaps because smaller birds radiate heat more efficiently because they have more surface area than volume.
Brian Weeks of the University of Michigan explained it this way:
“You can imagine there are a lot of small ice cubes in a glass of water, as opposed to one large ice cube, and the small ice cubes melt faster because the smaller things have a surface area to volume ratio. larger, so they exchange heat faster.”
Weeks didn’t do this particular study, but he did study the size of more than 50 species of migratory birds in North America a few years ago. He also found that nearly all of them were shrinking every decade.
Two studies support the idea that birds around the planet, migratory or not, could change shape as a result of a warming climate. Weeks said these kinds of changes should interest us all.
“Worldwide, humans depend on natural systems. Intact natural systems provide more economic benefits to humanity than the entire GDP of the world, so they are important to you whether you know it or not,” he said.
Jirinec said the timing of his paper’s publication couldn’t have been more appropriate.
“Our research [came] took place on the same day as the conclusion of the United Nations climate change conference in Glasgow. So those results really underscore the pervasive consequences of our actions on the planet,” he said.
