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A macaque on a bird nest search-and-destroy mission near Beijing.

A macaque on a bird nest search-and-destroy mission near Beijing.


Experts condemn China’s training of monkeys to destroy bird nests

BEIJING—Tomorrow, China’s government will mark the 70th anniversary of Japan’s formal surrender at the end of World War II by rolling tanks through Tiananmen Square and staging an airshow with jet fighters.

To safeguard China’s rarely seen military aircraft—the Chengdu J-20 and Shenyang J-31 fighter jets—from the risk of damage by accidental bird strikes, or birds sucked up into high-performance jet engines, the People’s Liberation Army (PLA) has trained a squadron of male rhesus macaques to search and destroy nests near an unnamed airfield, or airfields, in northern China.

Ornithologists say the operation is misguided, at best. “Many hungry and exhausted birds stop off in Beijing on their way south for the winter. If these birds are continually disturbed, it will cause extra stress and almost certainly higher mortality,” says Terry Townsend, founder of the birdwatchers group Birding Beijing.

The monkeys’ deployment began in late spring, according to military personnel who spoke with state media. “Our airfield is located along one of the eight flyways, the East Asian-Australasian Flyway, so large numbers of migrating birds come here around March every year and begin nesting near the airport, which creates significant safety hazards for flight,” Su Chuang, leader of the bird control team at an airbase under Beijing military command, told People's Liberation Army Daily.

PLA taught the macaques to scramble up trees and dismantle nests by pulling out twigs, airbase commander Wang Yuejian told China Daily in May: “Our statistics show that the two monkeys have taken out about 180 nests over the past month." In late August, Han Bing, political commissar of an unnamed airbase, bragged to the paper about the novel approach: “Using macaques to disperse birds has low costs and risks with high efficiency, and this is a first in the world."

Han further told China National Radio that the monkey method was an “ecological approach,” compared with blasting birds and nests with shotguns or water cannons, and that macaques left a scent on trees that would discourage migratory birds from returning. The military has also trained falcons to chase away other birds. No articles in state media mentioned the species of birds targeted.

Scientists and birdwatchers knowledgeable about the East Asian-Australasian Flyway—which spans 22 countries and is arguably the world’s most threatened flyway—question both the utility and the ecological logic of PLA’s scheme.

Spike Millington, chief executive of the nonprofit East Asian-Australasian Flyway Partnership, based in Incheon, South Korea, says that indiscriminate nest removal is not conducive to the army’s stated objective: “Small birds are not a threat to planes, only larger species like gulls and geese are usually involved in airstrikes.”

Nor is nest destruction without environmental impacts, though the consequences for migratory birds depend on the timing. For nests dismantled by monkeys in the spring, when birds lay eggs and feed young, “such an approach would likely result in quite high mortality [of nestlings, young birds too young to fly] and also in temporary abandonment of the colony, leading to reduced breeding success,” says Nial Moores, an independent researcher and director of the nonprofit Birds Korea in Busan.

Moores questioned the monkey trainers’ insights into birds’ olfactory instincts: “Most bird species have a poor sense of smell, so it is not the smell of the monkeys, but rather the direct threat that they pose that would lead birds to abandon the colony temporarily or over time. Repeated disturbance in the breeding season would lead to eventual abandonment of a site and relocation to a more secure site.” That could potentially backfire, he warns: “One issue then becomes the relative location of the feeding area to the new breeding site: Relocation of colonies could actually result in birds needing to fly further and more birds needing to fly across runways to forage.”

For birds harassed in the fall, close to the military parade date, Townsend explains that the main issue is not the nests themselves, which are likely empty after chicks hatch and leave—“most birds don't use nests at this time of year.” However, a concern is the ability of migratory birds to rest and refuel between long legs of their journey. “September is when migration of birds is in full swing,” he says. Several bird species fly from the Arctic to staging grounds in China and Korea, where they forage and molt feathers, before flying again to Southeast Asia or Australia.

Moores points out that alternative methods of reducing the risk of potential air strikes with larger birds exist. “Generally in North America and Europe, landscaping is used to help birds keep away from runways,” he says. “By landscaping, I mean cutting of long grass; removal of any sources of water; and in some cases … active planting and even small wetland creation in some peripheral parts so that birds moving across the airport are drawn away from the runways into safer edge areas.”

Townsend sees a larger pattern at work in the military’s efforts to suppress nature without studying or understanding it: “Destroying nests and chasing away all types of bird (even small) seems to me to be a very unnecessary and ineffective way to tackle the small risk to a military aircraft of a bird strike. More worrying is that policies of this kind reflect a general lack of understanding and appreciation of wildlife.”

As Moores puts it, more bluntly, training monkeys to destroy bird nests “seems to be yet another example of green-washing of behaviors that are rooted solidly in the human desire to control and not in any deep understanding of the issues.”