Bees Across America Stopped Buzzing During Last Year's Total Solar Eclipse

iStock.com/mafrmcfa
iStock.com/mafrmcfa

Most bees are diurnal creatures, meaning that they're active during daylight hours. After flying around all day, they start to slow down around dusk and return to their colonies at night to sleep.

Considering that daylight plays an important role in a bee's busy schedule, would a total solar eclipse thwart their plans? Would the bees think it's time to turn in for the night when the Moon passes in front of the Sun and blocks out its light? These are the questions researchers from the University of Missouri set out to answer when they tracked bee activity during the last total solar eclipse on August 21, 2017.

Their findings, published today in the Annals of the Entomological Society of America, yielded some surprises. Lead author Candace Galen said they expected to see bee activity gradually diminish as the sky darkened. "But we had not expected that the change would be so abrupt, that bees would continue flying up until totality [of the eclipse] and only then stop, completely," Galen said in a statement. "It was like 'lights out' at summer camp! That surprised us."

Of the 16 locations they tracked, only one bee was heard flying during the eclipse. This is one of the first studies to analyze how bees respond to a solar eclipse, and few studies like this have looked at similar behavior in other insects or animals. A 1991 study found that desert cicadas in Arizona stopped chirping for about 40 minutes during a partial solar eclipse. Another study from 1973 found that captive squirrels became restless and ran around far more during an eclipse, while other research showed that Blue bulls at a zoo in India altered their feeding and resting periods during a partial solar eclipse.

Before the latest bee study kicked off, researchers used tiny microphones and temperature sensors to track bee pollination by listening to them buzz about. That same method was applied to the solar eclipse experiment, and 16 monitoring stations were set up along the eclipse's path of totality in Oregon, Idaho, and Missouri. More than 400 scientists, citizens, and elementary school teachers and students assisted with the experiment.

The microphones were hung on flowers that bees had pollinated in semi-remote locations away from foot and vehicle traffic. After the eclipse, the recordings were sent off to Galen's lab, where researchers matched up flight activity with the different eclipse periods. In doing so, it was discovered that bees (mostly bumble and honey bees) kept flying during the partial-eclipse phases before and after the total eclipse. Practically no buzzing was recorded during the period of totality, save for one flight picked up by microphones.

Researchers also noticed that bees' flights were longer during those partial-eclipse phases, but they were likely slower flights as a result of the reduced light. They may have been returning to their hives, believing that it was time to rest, researchers suggested.

"The eclipse gave us an opportunity to ask whether the novel environmental context—mid-day, open skies—would alter the bees' behavioral response to dim light and darkness," Galen said. "As we found, complete darkness elicits the same behavior in bees, regardless of timing or context. And that's new information about bee cognition."

The next total solar eclipse in North America will take place on April 8, 2024, at which time Galen's team plans to do a second experiment. The researchers hope to improve their audio-analysis software to determine whether a bee is leaving or returning to its colony. That way, they'll be able to tell whether bees head home during a total eclipse.

Do Dogs Understand What You’re Telling Them? Scientists Are Scanning Their Brains to Find Out

iStock/kozorog
iStock/kozorog

We all know that dogs can learn to respond to human words, but it’s not always clear what’s happening in a dog’s brain when they hear and recognize words like “cookie” and “fetch.” Do they have to rely on other clues, like gestures, to figure out what we mean by that word? Do they picture a dog biscuit when you say “cookie,” or just the sensation of eating? In a new study, scientists from Emory University and the New College of Florida tried to get to the bottom of this question by training dogs to associate certain objects with words like “blue” and “duck,” then using fMRI brain scanners to see what was happening in the dogs’ heads when they heard that word.

The study, published in Frontiers in Neuroscience, examined the brains of 12 different dogs of various breeds (you can see them below) that had been trained to associate two different objects with random words like “duck,” “blue,” and “beach ball.” Those two objects, which were different for each dog, were brought by the dogs’ owners from home or chosen from a selection of dog toys the researchers compiled. One object had to be soft, like a stuffed animal, and the other one had to be something hard, like a rubber toy or squeaky toy, to make sure the dogs could clearly distinguish between the two. The dogs were trained for several months to associate these objects with their specific assigned words and to fetch them on command.

Then, they went into the fMRI machine, where they had been trained to sit quietly during scanning. The researchers had the dogs lie in the machine while their owners stood in front of them, saying the designated name for the toys and showing them the objects. To see how the dogs responded to unknown words, they also held up new objects, like a hat, and referred to them by gibberish words.

Dogs in a science lab with toys
Prichard et al., Frontiers in Neuroscience (2018]

The results suggest that dogs can, in fact, discriminate between words they know and novel words. While not all the dogs showed the same neural response, they showed activation in different regions of their brains when hearing the familiar word versus the novel one.

Some of the dogs showed evidence of a greater neural response in the parietotemporal cortex, an area of the dog brain believed to be similar to the human angular gyrus, the region of the brain that allows us to process the words we hear and read. Others showed more neural activity in other regions of the brain. These differences might be due to the fact that the study used dogs of different sizes and breeds, which could mean differences in their abilities.

The dogs did show a surprising trend in their brains’ response to new words. “We expected to see that dogs neurally discriminate between words that they know and words that they don’t,” lead author Ashley Prichard of Emory University said in a press release. “What's surprising is that the result is opposite to that of research on humans—people typically show greater neural activation for known words than novel words." This could be because the dogs were trying extra hard to understand what their owners were saying.

The results don’t prove that talking to your dog is the best way to get its attention, though—it just means that they may really know what's coming when you say, "Want a cookie?"

Scientists Find Fossil of 150-Million-Year-Old Flesh-Eating Fish—Plus a Few of Its Prey

M. Ebert and T. Nohl
M. Ebert and T. Nohl

A fossil of an unusual piranha-like fish from the Late Jurassic period has been unearthed by scientists in southern Germany, Australian news outlet the ABC reports. Even more remarkable than the fossil’s age—150 million years old—is the fact that the limestone deposit also contains some of the fish’s victims.

Fish with chunks missing from their fins were found near the predator fish, which has been named Piranhamesodon pinnatomus. Aside from the predator’s razor-sharp teeth, though, it doesn’t look like your usual flesh-eating fish. It belonged to an extinct order of bony fish that lived at the time of the dinosaurs, and until now, scientists didn’t realize there was a species of bony fish that tore into its prey in such a way. This makes it the first flesh-eating bony fish on record, long predating the piranha. 

“Fish as we know them, bony fishes, just did not bite flesh of other fishes at that time,” Dr. Martina Kölbl-Ebert, the paleontologist who found the fish with her husband, Martin Ebert, said in a statement. “Sharks have been able to bite out chunks of flesh, but throughout history bony fishes have either fed on invertebrates or largely swallowed their prey whole. Biting chunks of flesh or fins was something that came much later."

Kölbl-Ebert, the director of the Jura Museum in Eichstätt, Germany, says she was stunned to see the bony fish’s sharp teeth, comparing it to “finding a sheep with a snarl like a wolf.” This cunning disguise made the fish a fearful predator, and scientists believe the fish may have “exploited aggressive mimicry” to ambush unsuspecting fish.

The fossil was discovered in 2016 in southern Germany, but the find has only recently been described in the journal Current Biology. It was found at a quarry where other fossils, like those of the Archaeopteryx dinosaur, have been unearthed in the past.

[h/t the ABC]

SECTIONS

arrow
LIVE SMARTER