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Grasshoppers Have Evolved to Deal With Our Noise

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Image courtesy of Flickr user driverevan

Anyone who has ever lived by a busy street can tell you just how loud traffic can get. To compensate, humans can just talk a little louder to be heard, or turn up the volume on the TV if the sound of cars whizzing by overpowers it—but solutions to deal with the noise don't come so easy for other creatures. In fact, for grasshoppers to adjust to increased noise levels, the insects had to evolve a new sound that could still be heard above busy city streets.

German researchers came to this conclusion after studying the mating song between grasshoppers captured in the quiet countryside and those that lived near busy roads. The song of those in busy areas had a major boost in the low frequency component of their mating call in order to be heard.

While this might not seem like that big of a deal, the research marks the first time that insects have been found to change their behavior to deal with noise pollution. Researchers speculate that many other creatures may be adapting in a similar manner.

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Oakley Originals, Flickr Creative Commons // CC BY 2.0
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Animals
Could Imported Sperm Help Save America’s Bees?
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Oakley Originals, Flickr Creative Commons // CC BY 2.0

It might be time to call in some sexual backup for male American bees. Scientists have started impregnating domestic honeybees with foreign sperm in the hopes that enlarging the gene pool will give our bees a fighting chance.

These days, the bees need all the help they can get. Colonies across the globe are disappearing and dying off, partly due to the increased use of neonicotinoid pesticides and partly from a parasite called the varroa mite. The invasive mite first landed on American shores in 1987, and it's been spreading and sickening and devouring our bees ever since.

Part of the problem, researchers say, is that the American bee gene pool has gone stagnant. We stopped importing live honeybees in 1922, which means that all the bees we've got are inbred and, therefore, all alike. They lack the genetic diversity that allows species to adapt to changing conditions or new threats. So when the mites come, they all get hit.

Many apiarists now rely on anti-mite pesticides to keep their charges safe. While these treatments may help keep the mites away, they aren't great for the bees, either—and the mites have begun to develop a resistance. But beekeepers feel like their hands are tied.

"I lost 40 percent of my colonies to varroa last fall," Matthew Shakespear of Olson's Honeybees told NPR. "I'm not taking any more chances. We've already done five treatments, compared with the two treatments we applied this time last year."

But there might be another way. Experts at the University of Washington have started to—how can we put this delicately?—manually encourage drones (male bees) in Europe and Asia to give up their sperm. All it takes is a little belly rub, and the drone, er, donates 1 microliter of fluid, or one-tenth of the amount needed to inseminate a queen bee.

Fortunately, the bees don't mind at all. "They're really accommodating," bee breeder and researcher Susan Cobey told NPR.

So far, the scientists' attempts to crossbreed foreign and domestic bees have been successful. Within their test colonies, genetic diversity is up.

"This doesn't mean they are superior in performance to the other bees," researcher Brandon Hopkins said. "It means we have a better chance of finding rare and unique traits." Traits, Hopkins says, like genetic resistance to the varroa mites—a quality shared by donor bees in Italy, Slovenia, Germany, Kazakhstan, and the Republic of Georgia.

Other beekeepers are opting for a more hands-off approach, introducing imported queens to their domestic hives. Shakespear bought his from Cobey, who reared them from bees she collected in Slovenia.

"Maybe these new genetics can deal with the varroa mites naturally," Shakespear said, "rather than having to rely on chemicals. It's time to start widening our gene pool."

[h/t The Salt]

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Animals
Mantises Regularly Catch and Feast On Birds, NBD

The next time you feel like you’re too small to make a difference, think of the mantis. Scientists have discovered that many species of these badass little bugs habitually hunt, kill, and devour entire birds. A report on the mantises’ impressive skills was published in The Wilson Journal of Ornithology.

It’s not like we thought mantises were vegetarians. Their taste for flesh, including each other's, is common knowledge. But so was their basic diet, which consists of bugs and spiders. Once in a blue moon, someone might spot a mantis eating a tiny lizard or a small snake—you know, animals that live on the ground. But birds? Like, the kind with wings? No. How would that even work?

Apparently, the mantises are making it work. Researchers set out to collect and compare every single report they could find of a mantis eating a bird. They figured they’d find a few. Maybe one or two mantis species had figured it out.

One or two species had. As had another one or two. And another ten after that. All in all, the researchers discovered 147 accounts of bird-eating mantises from 12 different species. And this wasn’t some exotic local custom, either; the mantises were grabbing birds in 13 different countries, and on every continent except Antarctica (and that may only be because there are no mantises there).

The paper’s authors were floored by their own findings. "The fact that eating of birds is so widespread in praying mantises, both taxonomically as well as geographically speaking, is a spectacular discovery," lead author Martin Nyffeler of the University of Basel said in a statement.

Of course, we’re not talking about big birds here. Of the 24 bird species spotted in mantis mouths, many were hummingbirds. But hummingbirds are no joke, either. Males competing for territory and mates habitually stab each other in the chest. While hunting, they can snap their beaks shut in less than one hundredth of a second. They may be pretty, but they’re hardly helpless.

A male ruby-throated hummingbird at a red feeder.
"Come at me, bro."
Cephas, Wikimedia Commons // CC BY-SA 3.0

Nyffeler and his colleagues note that the bugs’ bird eating is more than a party trick. Farmers and gardeners regularly release mantises into the wild, relying on the insects’ appetites for pest control. But you can’t tell a mantis what to do. It might not want to eat your bugs, especially if there are juicy birds nearby. And birds aren’t doing so great right now. We should probably give them a break.

Still thinking of unleashing your own mantis horde? The authors advise “great caution.”

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