How other species handle social distancing when someone is sick


Social distancing can be hard for social animals like us, even when we know it’s a matter of life and death.

There are countless logistical crises, of course, but avoiding human contact is also just lonely for a species that evolved to live around each other, and many people are struggling to stay vigilant as the coronavirus lockdown drags on.

Yet while it may feel unnatural to live like this, the sacrifices we’re now making have deep roots in the animal kingdom. Social distancing occurs not only in species that always lead solitary lives, and thus avoid each other even when no one is sick, but also in some social species when circumstances call for it.

From ants and bees to mice, monkeys and apes, an array of social animals change their behavior to reduce the risk of spreading infections. Below is a closer look at how some other social species protect themselves and their communities from dangerous diseases. Many use strategies that wouldn’t work for humans, but they still illustrate why isolating ourselves during an outbreak isn’t as unnatural as it feels.


An ant colony is considered a “superorganism,” in which hordes of individuals work together as part of a larger entity, sort of like neurons in a brain. Considering how well ants collaborate on common goals, it may come as little surprise that they excel at social distancing and other methods of disease control. Still, their methods and results are impressive, both in terms of identifying pathogens and neutralizing them.

Black garden ants (Lasius niger), for example, quickly adjust their normal routines when members of the colony develop a fungal infection. Their colonies naturally include both nurses and foragers, who either stay home to care for young ants or venture out to find food. The latter group sometimes picks up pathogens during their excursions, but when they do, both nurses and foragers swiftly respond.

That response begins before the infected ants even become sick, according to a study published in the journal Science, in which researchers exposed some foragers in a colony to spores from a fungus called Metarhizium brunneum. Within one day of exposure, the infected foragers started spending even more time outside the nest than usual, further limiting their contact with other members of the colony.

It isn’t clear how the ants knew they were infected, but it’s possible they can detect the spores on themselves, New Scientist reports. However they knew, isolating themselves so early could make a big difference in stemming an outbreak — an opportunity many human communities missed during the coronavirus pandemic. In fact, similar to what countless people are now doing to avoid the coronavirus, it isn’t just infected ants who changed their behavior. Unexposed foragers also reduced their social contact after their colleagues picked up the spores, the researchers found, while nurse ants began moving the brood deeper into the nest.


Ants are the largest group of “eusocial” insects, who form complex societies with overlapping generations, cooperative brood care and reproductive division of labor. Nearly all ant species live this way, but so do several hundred species of bees and wasps, and they also must be vigilant to protect their tightly packed colonies.

That includes honey bees, one of the most famous of all eusocial insects, whose colonies can fall victim to a variety of bacteria, viruses, fungi and parasites. As with ants, the dense population of a honey bee hive means quick detection — and quick action — is needed to prevent a disease from running amok.

In a bacterial disease called American foulbrood, for instance, adult bees can smell certain chemicals emitted by infected larvae, namely a mixture of two pheromones that triggers a specific hygienic behavior. When bees smell this combo, they respond more consistently than they do to either pheromone alone, according to a study published in the journal Scientific Reports. Once the bees identify where this telltale smell is coming from, they’ll remove any infected larvae from the hive.


Until the late 1990s, there was no evidence that nonhuman animals could recognize and reduce infection risk from other members of their species. That changed with research on American bullfrogs, whose tadpoles are impressively adept at dodging a dangerous fungal infection. Tadpoles are able to detect an infection of Candida humicola in other tadpoles, the researchers found, and can then use that information to proactively avoid other tadpoles harboring such an infection.

“Our understanding of predators and their prey has changed drastically since it was discovered that many kinds of prey animals can change their behavior and even their body shape when they smell nearby predators,” study co-author and Yale University professor Skelly said in a statement at the time. “Responding to disease risk may be quite similar from an animal’s perspective. In both cases animals appear to be able to use behavior to reduce the chance that they will be harmed or die.”

Great apes

Like us, the great apes are highly visual creatures. Even if they can’t sniff out an infection like bees or tadpoles can, they may still use visual cues to stay healthy.

Western lowland gorillas, for example, live in social groups that females migrate to join, and as researchers reported in a 2019 study, disease avoidance can be a key factor when females are deciding to leave or join a group. The study looked at a bacterial disease known as yaws, which causes visible ulcers on the faces of infected animals. While studying nearly 600 gorillas over a decade, the researchers noticed females often leave males and heavily diseased groups to join healthier ones, avoiding other sick groups at all costs. This suggests gorillas have learned the disease is contagious, the researchers noted, and can recognize its symptoms in others.

Chimpanzees rely on visual cues, too, sometimes taking steps to limit infection that seem harsh to humans. As the famed primatologist Jane Goodall first reported in the 1960s, chimps may ostracize a member of their troop who has polio, a viral disease that can lead to paralysis. Healthy chimps have been known to shun or even attack chimps partially paralyzed by polio, although Goodall has noted some chimps eventually recovered and rejoined the social group.


In many social species, from insects to apes, animals recognize an infection in others and then take steps to avoid them. In house mice, however, the opposite also happens in at least some cases.

In a 2016 study, researchers examined how a disease outbreak might affect social dynamics of wild house mice living in a barn in Switzerland. To simulate an infection, mice were injected with lipopolysaccharides, a component of the bacterial cell wall, which results in an immune response and generalized disease symptoms, making the mice feel sick. All the mice were also identified and tracked with radio tags, letting the researchers learn how both sick and healthy mice responded.

Mice have the ability to detect illness in other mice, yet the researchers were surprised to discover healthy mice were not avoiding the sick mice, instead interacting with them as if nothing was different. “It was the sick mouse that removed itself from the group,” lead author Patricia Lopes, a biologist at the University of Zurich, said in a statement. That behavioral change might not be intentional — maybe the sick mouse just felt lethargic — but it could still be evolutionarily adaptive, since it would help protect the sick mouse’s relatives from the infection.


Although some of our fellow primates can be drastic with their disease avoidance — ejecting members from the social group, or abandoning the group themselves — the right solution depends largely on the species and the disease. In highly social mandrills, for example, a group member infected with parasites may not be ostracized entirely, but simply receive less grooming until healthy again.

Researchers discovered this as part of an ongoing research project on mandrills in Gabon. Following 25 mandrills over more than two years, they noticed grooming rates fell as individuals became infected with more parasites, but the infected monkeys were otherwise tolerated. The researchers collected fecal samples from the mandrills, too, noticing a different chemical signature in the poop of sick mandrills compared with healthy ones. Mandrills also showed more avoidance of poop with higher levels of parasites, suggesting they know when to cut back on someone’s grooming at least partly based on the smell of their poop.

When the researchers treated the sick mandrills and freed them of parasites, other members of their social groups started grooming them regularly again.

Vampire bats

Vampire bats live in colonies that can number in the hundreds or thousands, and they depend heavily on their social network for survival. That’s because the bats support each other with mutually beneficial behaviors like reciprocal grooming and food sharing, which can be important for survival. Vampire bats need to drink about a tablespoon of blood per night, and three days without blood could kill them. To buffer the colony against that threat, bats who successfully find blood on a given night often regurgitate and share some with less fortunate bats back at the colony.

In a recent study, researchers hoped to learn how an infection can affect the social dynamics among vampire bats. Working with a small captive bat colony at the Smithsonian Tropical Research Institute in Panama, the researchers injected some bats with bacteria to stimulate their immune systems and make them feel sick. All the bats continued

to socialize and share food, but the sick ones did make a few changes. Similar to humans, sick bats were more likely to withdraw from weaker social relationships — offering and receiving less grooming — but interacted more normally with close family members.

“Understanding how social interactions change in the face of illness is a key component in predicting the channels and speed at which a pathogen can spread across a population,” said co-author and STRI researcher Rachel Page in a statement. “Close observation of vampire bat behavior sheds light on how social animals interact, and how these interactions change — and importantly, when they do not change but persist — as individuals become sick.”

‘Rip Van Winkle’ plants can hide underground for 20 years


Rip Van Winkle, the titular ne’er-do-well of Washington Irving’s 1819 short story, famously spent 20 years napping in a forest. This lengthy slumber, apparently triggered by ghost liquor, caused Van Winkle to sleep through the American Revolutionary War.

Nearly two centuries later, scientists are shedding light on plants that do something similar in real life. A surprisingly diverse mix of plants around the world can live dormant underground for up to 20 years, researchers report in the journal Ecology Letters, a strategy that allows the plants to survive hard times by simply napping until things get better.

At least 114 species from 24 plant families are capable of this trick, in which a plant abandons photosynthesis to focus on survival in the soil. It’s a way for plants to hedge their bets, the study’s authors explain, by accepting certain short-term hardships — like missed opportunities to grow and reproduce — for the longer-term benefits of avoiding mortal dangers on the surface.

“It would seem to be paradoxical that plants would evolve this behavior, because being underground means they cannot photosynthesize, flower or reproduce,” says co-author Michael Hutchings, an ecology professor at the University of Sussex, in a statement. “And yet this study has shown that many plants in a large number of species frequently exhibit prolonged dormancy.”

So how do these Rip Van Winkle plants survive for up to 20 years without sunlight? Many species have found other ways to endure dormancy, Hutchings says, especially “by evolving mechanisms enabling them to obtain carbohydrates and nutrients from soil-based fungal associates.” Befriending soil fungi, he adds, “allows them to survive and even thrive during dormant periods.”

This strategy is used by many orchid species (including the lady’s slipper orchids pictured above), along with a wide variety of other plant types. It typically occurs in only part of a population or species during any given year, the researchers note, so the broader population can keep growing and reproducing while the designated survivors wait underground as backup.

Wild crows seem to obey ‘do not enter’ signs

Crows can’t read, but the signs have still apparently curbed their habit of stealing insulation material from a university building in Japan.

by Russell McLendon

Crows are incredibly clever birds. Some species use tools, for example. Some also recognize human faces, even “gossiping” about who’s a threat and who’s cool. Crows can hold long-term grudges against people they deem dangerous, or shower their allies with gifts. Oh, and they can solve puzzles on par with a 7-year-old human.

With wits like this, it’s little wonder crows have adapted to live in human cities around the world. Yet despite all their uncanny displays of intelligence, a recent example from Japan is eyebrow-raising even for these famously brainy birds.

Wild crows had learned to raid a research building in Iwate Prefecture, stealing insulation to use as nest material. But as the Asahi Shimbun reports, they abruptly quit after a professor began hanging paper signs that read “crows do not enter.”

The idea was suggested by a crow expert from Utsunomiya University, and has reportedly worked for the past two years. This doesn’t mean the crows can read Japanese, but it may still shed light on their complex relationship with people.

The building in question is the International Coastal Research Center (ICRC), part of the University of Tokyo’s Atmosphere and Ocean Research Institute in Otsuchi. The ICRC was founded in 1973 to promote marine research around the biodiverse Sanriku Coast, but its building was heavily damaged by the 2011 Great East Japan earthquake and tsunami, which flooded all three stories. Nearby houses were all destroyed, the Asahi Shimbun reports, and many residents have moved elsewhere.

Repairs later allowed temporary use of the third floor, but the first and second floors were just cleared for warehouse space. While the University of Tokyo has plans to rebuild the center and restart its research, that “is expected to cost a substantial amount of money and several years of time,” according to the ICRC website.

The crows began their raids on the damaged building in spring 2015, according to Katsufumi Sato, a behavioral ecologist and ethology professor at the University of Tokyo. Once inside, they would find insulated pipes, tear off chunks of insulation and then fly away, leaving behind feathers and droppings as clues of their crime.

“Crows take it for their nests,” Sato tells Shimbun staff writer Yusuke Hoshino.

Hoping for a simple solution, ICRC staff sought advice from Sato, who in turn asked his friend Tsutomu Takeda, an environmental scientist and crow expert at Utsunomiya University’s Center for Weed and Wildlife Management. When Takeda suggested making signs that tell crows to stay out, Sato says he thought it was a joke. But he gave it a try, and crows quit raiding the ICRC “in no time at all,” Hoshino writes.

Sato remained skeptical, assuming this was a temporary coincidence, but the crows stayed away throughout 2015, even though the building still had openings and still had insulation inside. He put up the paper signs again in 2016, and after another year without crow attacks, he kept up the tradition this spring. Crows can still be seen flying around nearby, Hoshino points out, but their raids seem to have ended.

So what’s going on? Crows can’t read, but could they still somehow be getting information from the signs? As the BBC documented a decade ago, some urban crows in Japan have learned to capitalize on traffic lights, dropping hard-to-crack nuts into traffic so cars will run over them, then waiting for the light to turn red so they can safely swoop down and grab their prize. That’s impressive, albeit not quite the same.

Takeda offers a different explanation. The crows aren’t responding to the signs at all, he says; they’re responding to people’s responses. People might normally ignore common urban wildlife like crows, but these warnings — while ostensibly directed at crows themselves — draw human attention to the birds. As ICRC staff, students and visitors see the strange signs, they often look up at the crows and even point at them.

“People gaze up at the sky [looking for crows], you know,” Takeda says.

For clever birds that pay close attention to people, that’s apparently eerie enough to make the ICRC seem unsafe. It’s worth noting this is anecdotal, not a scientific study, and there may be another reason why the crows stopped their raids. But given how closely it correlated with the new signs, and how perceptive crows can be, Takeda’s plan is being credited with cheaply and harmlessly keeping the birds at bay.

If nothing else, this is a reminder to appreciate these intelligent birds living all around us, even in cities we built for ourselves. But since crows are sometimes a little too good at exploiting urban environments, it’s also a helpful reminder of how much a dirty look can accomplish. Sato, now a believer in Takeda’s unorthodox strategy, hopes more people will come to the ICRC and gawk at the local crows.

Coyotes and badgers hunt together

by Russell McLendon

Competition and cooperation aren’t mutually exclusive. Just ask a coyote or a badger.

Both are crafty carnivores, and since they often hunt the same prey in the same prairies, it would make sense for them to be enemies, or at least to avoid each other. But while they don’t always get along, coyotes and badgers also have an ancient arrangement that illustrates why it can be smart for rivals to work together.

An example of that partnership recently unfolded on a prairie in northern Colorado, near the National Black-footed Ferret Conservation Center. And it was captured in photos, both by a wildlife camera trap and by sharp-eyed photographers:

While it’s relatively rare to capture such good photos of a hunt like this, the phenomenon is well-documented. It was familiar to many Native Americans long before Europeans reached the continent, and scientists have studied it for decades. It has been reported across much of Canada, the United States and Mexico, according to Ecology Online, typically with one badger hunting alongside one coyote.

(In one study at the National Elk Refuge in Wyoming, 90 percent of all coyote-badger hunts featured one of each animal, while about 9 percent involved one badger with two coyotes. Just 1 percent saw a lone badger join a coyote trio.)

But why would these predators work together at all? When one of them finally catches something, they aren’t known to share the spoils. So what’s the point?

The point, apparently, is to improve the likelihood that at least one of the hunters will snag some prey. Even if that means the other one ends up empty-handed, the partnership seems to pay off for both species in the long run.

Each member of the hunting party has a distinct set of skills. Coyotes are nimble and quick, so they excel at chasing prey across an open prairie. Badgers are slow and awkward runners by comparison, but they’re better diggers than coyotes are, having evolved to pursue small animals in underground burrow systems. So when they hunt prairie dogs or ground squirrels on their own, badgers usually dig them up, while coyotes chase and pounce. The rodents therefore use different strategies depending which predator is after them: They often escape a digging badger by leaving their burrows to flee aboveground, and evade coyotes by running to their burrows.

When badgers and coyotes work together, however, they combine these skills to hunt more effectively than either could alone. Coyotes chase prey on the surface, while badgers take the baton for subterranean pursuits. Only one may end up with a meal, but overall, research suggests the collaboration makes both predators better at their jobs. If you’re a prairie dog trying to escape this dynamic duo, good luck.

“Coyotes with badgers consumed prey at higher rates and had an expanded habitat base and lower locomotion costs,” according to the authors of the National Elk Refuge study. “Badgers with coyotes spent more time below ground and active, and probably had decreased locomotion and excavation costs. Overall, prey vulnerability appeared to increase when both carnivores hunted in partnership.”

Badgers and coyotes aren’t always friendly, though. While the majority of their interactions “appear to be mutually beneficial or neutral,” Ecology Online notes they do sometimes prey on each other. The two species have developed “a sort of open relationship,” according to the U.S. Fish and Wildlife Service (FWS), since they tend to collaborate in warmer months, then often drift apart as winter sets in.

“In the winter, the badger can dig up hibernating prey as it sleeps in its burrow,” the FWS explains. “It has no need for the fleet-footed coyote.”

Not at the time, anyway. But winter eventually turns to spring, and these two hunters may start to need each other again. And just as they have for thousands of years, they’ll make peace, embrace their differences and get back to work.

Mysterious noise in the Arctic Ocean appears to be scaring away wildlife


by Russell McLendon

A strange “ping” is emanating from the Arctic Ocean, according to reports from hunters and boaters in Canada’s Nunavut territory. The noise has been occurring for months, dating back to summer, and it correlates with fewer sightings of marine animals nearby. Some local hunters worry it’s scaring away wildlife.

Also described as a hum or beep, the mysterious sound seems to come from the seabed in the Fury and Hecla Strait, a narrow channel in the Qikiqtaaluk Region of Nunavut. It’s a remote area, about 120 kilometers (75 miles) from the hamlet of Igloolik, located within a stretch of open water surrounded by sea ice. Known as a “polynya,” this type of habitat is normally a popular hangout for wildlife.

“That’s one of the major hunting areas in the summer and winter because it’s a polynya,” Nunavut legislator Paul Quassa tells the CBC. “And this time around, this summer, there were hardly any [animals]. And this became a suspicious thing.”

Concerned for local wildlife, Quassa recently addressed the Nunavut legislature about the sound, which he said is “emanating from the sea floor.” A community radio show has also received calls from people who say they’ve heard the ping, including some who reportedly heard it through the hulls of boats.

The reports inspired another legislator to visit the area, too, and while he says hearing loss may have prevented him from hearing the sound, he did notice the absence of animals. “That passage is a migratory route for bowhead whales, and also bearded seals and ringed seals,” George Qulaut tells the CBC. “There would be so many in that particular area. This summer there was none.”

Sound travels relatively well in the ocean, and marine mammals often rely heavily on their sense of hearing, including many dolphins and whales. Underwater sonar is known to cause serious problems for a variety of sea creatures, so if these reports are accurate, it would make sense for the sound to affect wildlife.

The source of the sound remains unknown, but several theories have surfaced. One suggests it’s related to sonar surveys by the Baffinland Iron Mines Corporation, which mines iron ore from Canada’s Baffin Island. The company tells the CBC it isn’t surveying in that area, though, and has no equipment in the water. Quassa says Nunavut hasn’t issued any local work permits that might explain the noise.

Another theory goes a very different direction, accusing Greenpeace of generating the ping on purpose to drive animals away from the polynya, thus protecting them from hunters. Yet Quassa says there’s no evidence the environmental group has ever used sonar to disrupt Inuit hunts, and Greenpeace also denies any involvement.

“Not only would we not do anything to harm marine life, but we very much respect the right of Inuit to hunt and would definitely not want to impact that in any way,” Greenpeace spokeswoman Farrah Khan tells the CBC.

All this attention finally got a response from Canada’s Department of National Defence (DND), which sent military aircraft to investigate the area this week.

“The Canadian armed forces are aware of allegations of unusual sounds emanating from the seabed in the Fury and Hecla Strait in Nunavut,” DND spokeswoman Ashley Lemire says in a statement. “The air crew performed various multi-sensor searches in the area, including an acoustic search for 1.5 hours, without detecting any acoustic anomalies. The crew did not detect any surface or subsurface contacts.”

The crew did, however, “observe two pods of whales and six walruses in the area of interest,” Lemire adds. That doesn’t necessarily mean the sound is gone, or that it isn’t affecting wildlife, but “at this time, the Department of National Defence does not intend to do any further investigations,” she says.

Speaking to the Nunavut legislature on Thursday, Quassa thanked the military but also expressed doubt that we’ve heard the last of this ping.

“We want to thank the Department of National Defence for doing an investigation right away,” he said in Inuktitut, according to the CBC. “I know that they will keep investigating this and they will be kept informed by the hunters as well. I encourage hunters to keep telling the Department of National Defence what they hear.”

The ocean has a long history of surprising people with strange noises, from eerie choruses of singing fish to large whistling waves that can be detected from space. Earlier this year, researchers detected a subtle “buzzing or humming” sound in the remote Pacific Ocean, and could only speculate about its source.

Even if such noises usually turn out to be natural and harmless, staying attuned to our natural environment is always a good idea, Quassa added. Strange sounds, sights and smells could provide an early warning of some undiscovered ecological problem, and people who live nearby are the first line of defense.

“Sometimes there are mysterious things, and there are people who report those mysterious things,” he said. “I want to thank them.”

Cardinals are protecting people from West Nile Virus

The birds seem to buffer humans from West Nile virus, according to a new study, especially in cities with more patches of old-growth forest.

by Rusell McLendon

The northern cardinal is one of North America’s most familiar songbirds. From the scarlet feathers and pointed crest of males to the rich, rhythmic songs of both sexes, it’s an unmistakable icon of countless American forests, parks and backyards.

And as a new study demonstrates, northern cardinals are much more than just scenery and a soundtrack. As part of eastern North America’s native biodiversity, they can also play a key role in keeping ecosystems — including humans — healthy.

That’s according to new research from Atlanta, where a team of scientists wanted to figure out why more people don’t get sick with West Nile virus (WNV). The mosquito-borne virus is zoonotic, meaning it can be spread between humans and other animals by a “bridge vector,” a role played by Culex mosquitoes for WNV.

Since WNV was introduced to the U.S. in 1999, it has become the country’s most common zoonotic disease carried by mosquitoes, causing more than 780,000 infections and 1,700 deaths. But for some reason, the virus sickens people in some areas more than others. It’s abundant in both Georgia and Illinois, for example, showing up in nearly 30 percent of birds tested in Atlanta, compared with 18.5 percent in Chicago. Yet only 330 human cases have been reported throughout Georgia since 2001, while Illinois has seen 2,088 human cases since 2002.

“When West Nile virus first arrived in the United States, we expected more transmission to humans in the South, because the South has a longer transmission season and the Culex mosquitos are common,” says senior author Uriel Kitron, chair of environmental sciences at Emory University, in a statement. “But even though evidence shows high rates of the virus circulating in local bird populations, there is little West Nile virus in humans in Atlanta and the Southeast in general.”

The reason for that difference has remained a mystery for years, prompting a three-year study by a team of scientists from Emory, the University of Georgia, the Georgia Department of Transportation and Texas A & M University. They collected mosquitoes and birds from various sites across Atlanta, tested them for WNV, and analyzed DNA from their blood meals to learn which birds they’d been biting.

“We found that the mosquitoes feed on American robins a lot from May to mid-July,” says lead author Rebecca Levine, a former Emory Ph.D. student now working at the U.S. Centers for Disease Control and Prevention (CDC). “But for some unknown reason, in mid-July, during the critical time when the West Nile virus infection rate in mosquitos starts going up, they switch to feeding primarily on cardinals.”

Previous research has shown American robins act as “super spreaders” of WNV in some cities like Chicago, Levine adds. Something about their blood creates a favorable environment for WNV, so the virus amplifies wildly once a robin is infected, meaning the birds can more efficiently pass it to new mosquitoes when bitten.

But cardinals have the opposite effect. Their blood is like an abyss for WNV, leading the researchers to describe the birds as “super suppressors” of the virus.

“You can think of the cardinals like a ‘sink,’ and West Nile virus like water draining out of that sink,” Levine says. “The cardinals are absorbing the transmission of the virus and not usually passing it on.” Cardinals seem to be the top suppressors of WNV, the study found, but similar effects are seen in birds from the mimid family — namely mockingbirds, brown thrashers and gray catbirds, all of which are common in Atlanta.

Wild birds communicate and collaborate with humans, study confirms

Humans use a unique call to request help from honeyguide birds, and the birds also ‘actively recruit’ human partners. This is two-way teamwork, scientists say, a rarity between people and wildlife.

By Russell McLendon


When a human makes that sound in Mozambique’s Niassa National Reserve, a wild bird species instinctively knows what to do. The greater honeyguide responds by leading the human to a wild beehive, where both can feast on honey and wax. The bird does this without any training from people, or even from its own parents.

This unique relationship pre-dates any recorded history, and likely evolved over hundreds of thousands of years. It’s a win-win, since the birds help humans find honey, and the humans (who can subdue a beehive more easily than the 1.7-ounce birds can) leave behind beeswax as payment for their avian informants.

While this ancient partnership is well-known to science, a new study, published July 22 in the journal Science, reveals incredible details about how deep the connection has become. Honeyguides “actively recruit appropriate human partners,” the study’s authors explain, using a special call to attract people’s attention. Once that works, they fly from tree to tree to indicate the direction of a beehive.

Not only do honeyguides use calls to seek human partners, but humans also use specialized calls to summon the birds. Honeyguides attach specific meaning to “brrr-hm,” the authors say, a rare case of communication and teamwork between humans and wild animals. We’ve trained lots of domesticated animals to work with us, but for wildlife to do so voluntarily — and instinctively — is pretty wild.

Here’s an example of what the “brrr-hm” call sounds like:

“What’s remarkable about the honeyguide-human relationship is that it involves free-living wild animals whose interactions with humans have probably evolved through natural selection, probably over the course of hundreds of thousands of years,” says lead author Claire Spottiswoode, a zoologist at the University of Cambridge.

“[W]e’ve long known that people can increase their rate of finding bees’ nests by collaborating with honeyguides, sometimes following them for over a kilometer,” Spottiswoode explains in a statement. “Keith and Colleen Begg, who do wonderful conservation work in northern Mozambique, alerted me to the Yao people’s traditional practice of using a distinctive call which they believe helps them to recruit honeyguides. This was instantly intriguing — could these calls really be a mode of communication between humans and a wild animal?”

To answer that question, Spottiswoode went to Niassa National Reserve, a vast wildlife refuge larger than Switzerland. With the help of honey hunters from the local Yao community, she tested whether the birds can distinguish “brrr-hm” — a sound passed down from generation to generation of Yao hunters — from other human vocalizations, and if they know to respond accordingly.

She made audio recordings of the call, along with two “control” sounds — arbitrary words spoken by the Yao hunters, and the calls of another bird species. When she played all three recordings in the wild, the difference was clear: Honeyguides proved much more likely to answer the “brrr-hm” call than either of the other sounds.

“The traditional ‘brrr-hm’ call increased the probability of being guided by a honeyguide from 33 percent to 66 percent, and the overall probability of being shown a bees’ nest from 16 percent to 54 percent compared to the control sounds,” Spottiswoode says. “In other words, the ‘brrr-hm’ call more than tripled the chances of a successful interaction, yielding honey for the humans and wax for the bird.”

The researchers released this video, which includes footage from their experiments

This is known as mutualism, and while lots of animals have evolved mutualistic relationships, it’s very rare between humans and wildlife. People also recruit honeyguides in other parts of Africa, the study’s authors note, using different sounds like the melodious whistle of Hadza honey hunters in Tanzania. But aside from that, the researchers say the only comparable example involves wild dolphins who chase schools of mullet into anglers’ nets, catching more fish for themselves in the process.

“It would be fascinating to know whether dolphins respond to special calls made by fishermen,” Spottiswoode says.

The researchers also say they’d like to study if honeyguides learned “language-like variation in human signals” across Africa, helping the birds identify good partners among the local human population. But however it began, we know the skill is now instinct, requiring no training from people. And since honeyguides reproduce like cuckoos — laying eggs in other species’ nests, thus tricking them into raising honeyguide chicks — we know they don’t learn it from their parents, either.

This human-honeyguide relationship isn’t just fascinating; it’s also threatened, fading away in many places along with other ancient cultural practices. By shedding new light on it, Spottiswoode hopes her research can also help preserve it.

“Sadly, the mutualism has already vanished from many parts of Africa,” she says. “The world is a richer place for wildernesses like Niassa where this astonishing example of human-animal cooperation still thrives.”

Ping-Pong is good for the brain


Ping-Pong, or table tennis, is played by some 300 million people worldwide, according to the International Table Tennis Federation (ITTF), making it one of Earth’s most popular sports. It has been an Olympic sport since 1988, and its U.S. cachet has spiked in recent years amid the rise of hip Ping-Pong hangouts like New York’s SPiN and Portland’s Pips & Bounce.

It’s not hard to see why. Ping-Pong is accessible for beginners, has relatively low injury risk, and works as a boozy bar game or intense test of wills. And despite long being relegated to garages and basements, Ping-Pong is also increasingly billed as a “brain sport,” featuring a mix of aerobics, strategy, quickness and coordination.

“There is a lot going on in table tennis,” says Wendy Suzuki, a tenured professor of neuroscience at New York University and author of “Healthy Brain, Happy Life,” a new book exploring how physical exercise can affect the human brain. “Attention is increasing, memory is increasing, you have a better mood. And you’re building motor circuits in your brain. A bigger part of your brain is being activated.”

Of course, Ping-Pong is only one path to the mental perks of exercise, Suzuki adds, and since not enough research has focused on its effects, we can’t be sure how it stacks up with other options. Many people prefer simpler activities like walking and running, for example, or more aerobic, larger-scale sports like lawn tennis.

Still, Ping-Pong has a certain mojo that’s hard to replicate. Its small playing area tends to accelerate the action, encouraging players to think and move at a dizzying pace. It’s a game of strategy, too, like high-speed chess without chairs. And not only can it complement a broader fitness regimen, but it’s also a gateway sport, masquerading as mindless fun until it gets our brains — and bodies — hooked on speed.

The sport of pings

Table tennis, like its outdoor ancestor, was born in England. The sport dates back to the late 19th century, according to the International Olympic Committee (IOC), and was pushing players to use their heads from the very beginning:

“It is thought that upper-class Victorians in England invented table tennis in the 1880s as a genteel, after-dinner alternative to lawn tennis, using whatever they could find as equipment. A line of books would often be the net, the rounded top of a champagne cork would be the ball and occasionally a cigar box lid would be a racket.”

This inspired several commercial spinoffs by the 1890s, although they didn’t sell well because the balls were either rubber (too wild) or cork (too mild), explains the ITTF. When celluloid balls debuted in 1900, table tennis finally got the bounce it needed.

Beyond changing the game itself, celluloid balls also gave it a new name: “Ping-Pong.” That phrase reportedly came from an 1884 song by English songwriter Harry Dacre, repurposed to describe the sound of a celluloid ball bouncing off a paddle.

Early versions of the game also went by a variety of other names, including: Whiff-Waff, Pim-Pam, Flim-Flam, Gossima, Netto and Parlor Tennis.

“Ping-Pong” proved most popular, but since it was trademarked, many similar games were marketed simply as table tennis. That remains the sport’s official name, yet while Ping-Pong is still a U.S. trademark — now owned by Indiana-based Escalade Sports — it also lives on as a widespread nickname for the sport.

The first standard rules, and world championships, came in 1926 with the founding of the ITTF. Japan’s Hiroji Satoh later upended the table-tennis world in 1952, and not just as the first non-European player to win a world title: He became the first person in history to win using a paddle coated in foam rubber. Its spin was a literal game-changer, and table tennis soon embraced foam as its future.

That began a shift in Ping-Pong power from Europe to Asia, as Japan, China and Korea went on to dominate international play for decades. The sport also served as a cultural and political bridge, most famously in the April 1971 Ping-Pong diplomacy, which helped restore relations between the U.S. and China.

Seventeen years later, table tennis debuted at the 1988 Olympics in Seoul, giving the former parlor game a new level of athletic legitimacy. Players have backed it up, too, smashing a 2.7-gram (0.1-ounce) ball at up to 150 kilometers per hour (93 miles per hour), often with seemingly impossible spin. But even at less than Olympic speeds, Ping-Pong can bring a lot more to the table than its casual origins might suggest.

Live pong and prosper

“I play table tennis for the same reason people do crosswords,” says Will Shortz, New York Times crossword puzzle editor and owner of Westchester Table Tennis Center (WTTC) in Pleasantville, New York. “It refreshes me and relaxes me. I get wrapped up in a game, and afterward I feel great and ready to go back to life.”

Shortz is famed for his puzzle-building skills, with a list of accolades too long to list here, but he’s also a table-tennis celebrity. He opened the WTTC in 2011, and even recently helped 18-year-old Chinese player Kai Zhang move to New York, where he’s already ranked No. 1 in the U.S. and hopes to represent his new country in the Olympics. But perhaps Shortz’s main claim to Ping-Pong fame is The Streak:

The Streak was only meant to last a year, but as the video above notes, Shortz kept going past 365 days because “his brain was too happy.” In fact, he still plays daily, and has done so for more than three-and-a-half years. When we spoke recently, he was still going strong at nearly 1,300 consecutive days of Ping-Pong.

“It built up over time. I had other streaks before I started this one,” he says. “I had one streak that went for 80 days before I had a trip to Europe and broke it. The next one went for 280 days before I missed a day.” That was in Croatia, where he’d made plans to play at a local table-tennis club but couldn’t get there in time.

“That was the last day I missed,” he adds. “Oct. 3, 2012, was the last day I didn’t play.”

Shortz says he isn’t aware of, or interested in, any official record for such a streak. He really just plays Ping-Pong every day because it rejuvenates him.

“Any exercise is good if it gets blood going through the entire body,” he says. “I think table tennis is especially good because it’s a brain sport, training your body to perform instantly in different situations.” By forcing us to anticipate our opponents’ moves, then react with both speed and precision, Ping-Pong “is a way of getting the brain and the body prepared for everything else you do in life.”

Staying on the ball

So what actually happens inside your head during Ping-Pong? We don’t have the brain scans to know for sure, but other exercise research does provide some hints. Based on her professional expertise in neuroscience, plus her personal experience with exercise, Suzuki offers a few basic examples of your brain on Ping-Pong:

Mood: “The one thing we know that can happen immediately, that certainly happens to me when I exercise, is the mood boost,” Suzuki says. “This is not specific to table tennis; anything that is aerobic will give you a mood boost, because it increases the neurotransmitters that are decreased in depression.”

Neurotransmitters are vital chemicals that regulate various brain functions, and aerobic exercise affects major ones like dopamine (movement, emotional responses, feelings of pleasure), serotonin (mood, appetite, sleep, memory) and norepinephrine (stress response). On top of boosting moods in the short-term, regular exercise is associated with reduced depression and anxiety over time.

Motor control: There are other long-term perks, too. “We know there are a lot of changes in the motor cortex, the part of the brain’s outer covering that lights up when you do any voluntary movement, and in the cerebellum, which is critical for fine motor control,” Suzuki says. “This is a wonderful example of brain plasticity, the ability of the brain to change based on an experience or environmental factors.”

Memory: Aerobic activity can also raise levels of brain-derived neurotrophic factor (BDNF), a protein that promotes neuron growth and survival, thus helping fend off diseases like Alzheimer’s and Parkinson’s. In fact, exercise is a great way to get new brain cells, says Suzuki, who specializes in brain regions linked to memory.

“The hippocampus is special not only because it’s important for memory, but also because it’s one of the only brain structures that keeps making brand-new brain cells into adulthood,” she says. “In most of the brain, whatever cells you’re born with are all you get. But in the hippocampus, there’s a steady birth of new brain cells throughout our adult life. And the cool thing is we know that physical aerobic exercise will stimulate the growth of more brain cells and will help them survive longer. In studies of animals, that’s correlated with increases in various kinds of memory.”

Attention: “And the final one, the one we know the most about in humans, is that increased aerobic exercise will improve your ability to shift and focus attention,” she says. “Certainly that’s what you’re getting in table tennis. You’re getting improved attention, and you’re practicing your attention capacities — keeping your eye on the ball, anticipating what will happen next.”

All pings to all people

Playing Ping-Pong can do wonders for our brains, but Suzuki adds an important footnote: “One caveat is that if you play really slowly, those benefits may drop off. So these comments are more about the aerobic play of Ping-Pong.”

The idea of Ping-Pong as aerobic exercise might have seemed silly in the early 20th century, and some people still see it more as a casual game than a serious sport. But therein lies its beauty: Thanks to a simple premise and variable pace, Ping-Pong can be both. It’s accessible to beginners who need to play slowly, but regular practice also trains veteran players to move (and think) at incredible speeds.

One of those veterans is Sean O’Neill, a former Olympic player and coach who was inducted into the USA Table Tennis (USATT) Hall of Fame in 2008. Video of Olympic table tennis on TV and YouTube “has shown the dynamic ability of the players on a more regular basis,” he says, and inspired a surge of popularity. “More and more recreational players are buying professional quality equipment to copy the pros.”

As an Olympian, O’Neill says he loves to see the sport’s increasingly global appeal. “No matter where you go, table tennis is viewed as a great sport which anyone can play. I think most people are attracted due to the non-discriminatory nature of the sport,” he says, noting that it can be fun for people of all ages, sizes, physical conditions or skill levels. And that makes it especially valuable as an entry point for people who might not otherwise see themselves as athletes.

“We see a trend of both creative people and those from science really fall in love with the sport,” O’Neill says. “There is something about fast-action problem solving with spin, speed and placement that seems to excite these crowds. It is non-impact and a great cardio workout with low joint and bone stress. Many players have a tough time stopping once they pick up the paddle.”

Head of the table

Shortz clearly fits that profile. “I’m an obsessive person,” he admits, but “in a good way, I think.” And while his level of commitment may be uncommon, he agrees with O’Neill that this everyman’s sport has unusual appeal for eggheads, too.

“My experience is that table tennis attracts smart people,” Shortz says. “You don’t have to be a genius to play, but it helps to have something on the ball.”

Ping-Pong’s popularity has waxed and waned over time, he adds, and it still has a long way to go before most Americans see it as a serious sport. “But I think things are on the upswing,” he says. “It has become semi-cool. Social Ping-Pong clubs are open all around now, and I think being in the Olympics has conferred legitimacy.”

Its reputation as a brain sport may be helping, too, although Suzuki notes we can’t easily quantify a sport’s braininess. Almost any aerobic activity could be considered a brain sport, and there isn’t enough research to indicate more cognitive benefits from table tennis than from basketball or badminton. Instead of waiting for that research to come out, however, she has a better idea: Do the research yourself.

“I like to encourage people to do their own experiments on themselves,” she says. “See if you notice the mood shift from exercise. People get sucked back into, ‘Oh, I’m so busy, I’m so stressed, I don’t have time for that,’ without noticing how much even a single bout of exercise can improve your mood and give you more energy.

“Just do it once,” she adds, “and see if it motivates you to continue.”

If it’s still a habit 1,300 days later, your brain must be pretty happy.