On China’s border with Vietnam, a gaggle of about 500 geese stand guard, ready to honk at or bite anyone who tries to enter illegally.
Since October 2021, the Chinese government has deployed this so-called “geese army” across 300 miles of China’s Chongzuo Prefecture in an effort to stop the coronavirus from entering China via illegal immigration. Chinese domestic geese need no training; once they establish their territory, the five-pound birds defend it fiercely.
Reinforcing this feathered garrison are about 400 mixed-breed guard dogs, which accompany border police on patrol while the birds keep stationary watch. Together the interspecies team is key in maintaining China’s zero-COVID policy, which aims to eliminate the virus from within the country. Across mainland China, coronavirus infections are rising, and Shanghai, a city of 25 million, is under lockdown to prevent further spread. (Read how coronavirus evolution is still surprising experts, two years later.)
And guard geese may be helping: In December 2021, a goose allegedly honked the alarm to help catch two people illegally crossing the border, according to the state-funded news website The Paper. The Chongzuo Prefecture government did not respond to National Geographic’s request to confirm the event.
Using geese to uphold pandemic policy may be new, but the practice is age-old.
Domesticated geese originated at least 5,000 years ago and possibly even 16,000 years ago, which would make them the second oldest domesticated animal after dogs, according to a recent study.
Historical records are rich with tales of geese battalions, including one gaggle credited with trumpeting the alert and saving Rome from a secret Gaul invasion in 390 B.C. “The goose is carefully watchful; witness the defense of the capitol when the silence of the dogs would have betrayed nothing,” Roman author Pliny the Elder wrote at the time.
Another gaggle, known as the Scotch Watch, patrolled 14 acres of warehouses protecting 300 million pounds worth of Scottish whisky in Dumbuck, Scotland, from 1959 until 2012. And in 1986, the U.S. Army tried out 18 geese to safeguard radar and anti-aircraft installations in West Germany. The geese were so successful that the army conscripted 900 more geese for service in the region.
Indeed, geese may have an edge over canines, particularly because the birds are more selective about raising an alarm, says Petr Glazov, chair of the International Union for Conservation of Nature’s Goose Specialist Group.
“Dogs can sound the alarm sometimes just for fun or to talk together from dog to dog. But geese will only do so if there’s an intruder that goes into their special area,” Glazov says.
Before enlisting the geese, which are likely raised at nearby farms, the Chinese government tested a small deployment of the birds in June 2021.
In that experiment, the geese proved even more sensitive to strangers and noise than dogs, the state-funded news organization South Country Morning News reported. A few months later, the local government decided to deploy geese along 300 border checkpoints.
The geese’s ability doesn’t come as much of a surprise to Lauren Thielen, a doctor of veterinary medicine who has worked with domestic geese at the Texas Avian and Exotics Hospital outside Dallas.
“If you walk onto a geese's turf, they will almost charge you, honk, and use intimidation tactics, versus running away like most birds,” Thielen says by email.
“I have seen this with both wild Canada geese protecting their babies, as well as domestic Chinese geese protecting their environment.” (Watch an Egyptian goose feign injury to protect its chicks from a leopard.)
“I always think of them as bossy birds,” she says.
About 30 species of wild geese live on all the continents except Antarctica. The mostly ground-nesting birds have excellent eyesight, which evolved to spot predators approaching from afar. They can also use and control each eye separately, giving them a broader perspective.
When sleeping, geese can also leave one side of the brain awake and the eye connected to it open to detect threats—a rare phenomenon known as unihemispheric slow wave sleep. “They are always in control of the situation,” he says.
Wild geese, such as barnacle geese in northern Europe and Russia, usually make use of “security geese” on the edge of flocks to sound the alarm against threats. The geese are so proficient at sensing danger that ducks and cranes will sometimes feed among geese for security, says Glazov. (Learn how baby barnacle geese can survive extreme falls.)
What’s more, guard geese are cheaper: They basically take care of themselves, feeding on grass and not requiring veterinary care.
But what about dogs?
Dogs do have an advantage over geese because they can be trained for multiple purposes, says Ambrose Contreras, a canine trainer in the 341st Training Squadron of the Air Force, the group of the U.S. military that specializes in training dogs for detection and patrol.
“Could we train a goose? Probably, but that would be very hard,” he says. Contreras says dogs are also generally more intimidating: “I’m less inclined to try to do anything mischievous when I see a canine and its handler than a guy with a goose.”
And when it comes to a sense of smell, “dogs’ olfactory systems are on a scale of its own,” he says. (Learn how search-and-rescue dogs find survivors.)
Patrol dogs in the 341st squadron must detect a scent from someone at least 50 yards away and hear from at least a hundred feet before they go on to more advanced and specialized training.
Though the guard goose responsible for alerting authorities to the border interlopers in 2021 was highly celebrated in Chongzuo’s state-owned news—even earning the label “brother goose”—a dog also reportedly intercepted an illegal entrant in August 2021.
So at least for now, it’s brother goose 2, guard dog 1.