Conservation biologist David S. Wilcove was on a birding trip to the Indonesian island of Sumatra in 2012, when he began to notice that house after house in every village he visited had cages hanging outside, inhabited by the kinds of wild birds he had expected to see in the forest. One in five households in Indonesia keeps birds as pets. That got him thinking, “What is this doing to the birds?”

To find out, Wilcove, who teaches at Princeton University, made a detour from his planned itinerary to visit the Pramuka bird market in the capital city of Jakarta, Southeast Asia's largest market for birds and other wildlife, from bats to monkeys. “It was this sort of Walmart-size space filled with hundreds of stalls,” each of which was filled with hundreds of birds, he recalls. “An awful lot of them were in very poor condition, with signs of disease, feathers frayed, behaving listlessly—or thrashing around in their cages because a lot of these are wild birds that are not at all suited to living as caged birds.” Some were species that even zoos with highly trained professional staff cannot maintain in captivity; they would die soon after purchase, “the cut-flower syndrome,” Wilcove remarks. “It was really a shocking sight. I've never seen anything like it.”

Research by Wilcove and his colleagues subsequently linked demand for birds in Indonesia's pet marketplace to the decline of numerous species in the wild. Prices in the pet market, they suggested in a 2015 study in Biological Conservation, can even serve as an alarm system for species declines that might not show up in field studies until years later, if at all: when the average price for a white-rumped shama, a popular species in Indonesian songbird competitions, shot up by 1,500 percent from 2013 to 2015, the shift tipped off conservationists that these birds were vanishing from the wild.

Follow-up field studies in Indonesia by Bert Harris, a co-author of the 2015 study now at the Virginia-based Rainforest Trust, found no trace of white-rumped shamas, even in seemingly intact habitats where they should thrive, such as forests five kilometers from the nearest roads. Buyers were paying especially high prices for vulnerable island populations of the birds, many of them now recognized as separate species but valued by collectors for novel features such as long tails or distinctive songs. The pet trade has “the potential to drive species to extinction even when they have suitable habitat,” Wilcove observes, “and to do so without anyone being aware of it.”

The problem is not just about birds. Nor is it limited to Indonesia or other developing nations. The trade in wild-caught pets is driven at least as much by demand from collectors in the U.S. and Europe. Aquariums in the U.S., for example, are the final destination for about 11 million fish, along with other marine creatures, plucked from coral reefs every year, by some estimates. American pet dealers annually import 225 million live animals on average. They brought in more than three billion over the first 14 years of this century, according to a recent study in EcoHealth. Despite the widespread belief that our love of pets is one of the finer aspects of human nature, researchers increasingly suggest that it has become a major force in what they call defaunation, the great vanishing of wildlife from habitats of all kinds, almost everywhere.

Beyond Habitat Loss

For decades conservationists emphasized the role of ecosystem destruction in driving biodiversity decline. But the booming trade in wild animals, with more species taken to meet international demand for pets than for any other purpose, has caused increasing alarm. “The idea that habitat loss is the greatest threat to species survival is starting to be questioned,” says Crawford Allan of the wildlife trade-monitoring network TRAFFIC, a collaboration between the WWF and the International Union for Conservation of Nature (IUCN). “There are certain species that have plenty of habitat; however, they are being sucked up from the wild at alarming rates.”

Consumer demand for rare species has made the pet trade a source of special concern among conservationists. The IUCN Red List of Threatened Species already includes many species pushed to the brink by trapping for the pet trade, among them birds (the Bali myna and South America's Spix's macaw), a primate (Southeast Asia's greater slow loris), ornamental fishes (Asia's red line torpedo barb) and reptiles (Madagascar's radiated and ploughshare tortoises). And these are just the well-studied species, according to Wilcove and Harris. For the vast majority of vertebrates sold in markets and pet stores, researchers have not even begun to assess how the pet trade affects wild populations.

Field studies to answer such questions inevitably progress slowly, but the market for pets can move with devastating and unpredictable speed. In one notorious case from the 1990s, researchers published the first scientific description of the Roti Island snake-necked turtle, including the standard details about where it lives—an island in southern Indonesia. Collectors pounced, and the species is now critically endangered. Having learned this painful lesson, biologists withheld precise location information in 2011, when they described the new Matilda's horned viper from the highlands of southern Tanzania. Dealers nonetheless had the snakes on the market that same year at more than $500 apiece, according to a 2016 study of the European reptile trade published in Biological Conservation.

Wild animals are harvested by the millions for the exotic pet trade. The creatures are often sold illegally in local markets or smuggled overseas. Many die in transit from the poor conditions. Credit: Alamy (loris); Getty Images (parrots); Bullit Marquez AP Photo (snakes); Subhendu Sarkar Getty Images (birds in cages)

Dealers and collectors justify the sale of wild-caught animals as pets under the guise of conservation, observes a reptile trade investigator who asked not to be named: “They say, ‘We are maintaining insurance populations.’ Or, ‘The wild habitat is being destroyed, so we are protecting these animals.’ In the vast majority of cases, that's not true.” Rather, the investigator asserts, the pet trade itself is decimating wild populations.

For instance, the critically endangered ploughshare tortoise, a handsome species with a domed, golden shell, lives only in Baly Bay National Park in northwestern Madagascar. Commercial exploitation has been banned since 1975 under the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), and conservationists worked for decades to rebuild the population in the wild to an estimated 600 to 800 individuals. But over the past five years a surge in poaching to supply collectors has reduced the ploughshare population at Baly Bay to fewer than 100 adults. In countries such as Thailand, Indonesia and China, which tend to honor CITES rules on paper but not in practice, speculators have driven the price for a large ploughshare adult up to $100,000.

Financial speculation was also the apparent motivation in 2015, when a Chinese businessman paid more than $200,000 for a red-necked pond turtle, a species from southern China now thought to be extinct in the wild. “The more rare species get, the closer to extinction, the more these dealers promote that as a sales thing, and the higher the prices become,” says Rick Hudson, a herpetologist and president of the Texas-based nonprofit Turtle Survival Alliance.

The same players who supply the trade in wild animal parts—from rhinoceros horn to crocodile skin—are also fueling the pet trade. “Many of these people who were doing the traditional medicine trade are now branching out because the high-end pet trade in China has grown immensely” and has escalated prices in Europe and the U.S., says Brian Horne, a herpetologist for the Wildlife Conservation Society. Criminal elements have also gotten involved, at times targeting the captive breeding facilities set up by conservationists to rebuild populations of imperiled species. Thieves broke into one such facility last year in Thailand and stole six ploughshares and 72 radiated tortoises. They also target collectors. In Hong Kong last year, for instance, robbers broke into a family's home, scaling drainpipes and bypassing security cameras to steal 23 endangered turtles worth an estimated $116,000.

Catching and prosecuting people who traffic in illegal wildlife is one obvious way to slow the emptying of natural habitats. In 2016 a judge sentenced a Pennsylvania man to two years in prison in a scheme to export North American wood turtles, a threatened species. According to federal investigators, John Tokosh, then age 54, collected 750 of them from a small area south of Pittsburgh, immobilized them with duct tape for shipping and sold them at $400 apiece to middlemen supplying the pet trade in Hong Kong. That case also led to jail terms for a postal worker in Louisiana and collaborators in Chicago and California.

But such prosecutions are relatively rare. The enormous scale of the pet trade, both into and out of the country, inevitably overwhelms port inspectors working to spot contraband. “We do a lot of these blitzes, we call them, and it's such an absolute needle in a haystack,” says one U.S. Fish and Wildlife Service inspector who asked to not be named because he was not authorized to speak to the press. “We have all the tools. We've gotten more equipment and more people. We have a great intelligence unit. It just seems like we're always behind the eight ball. By the time we figure it out, everything has changed.” In one case, a dealer smuggled an orangutan into the country by trimming its hair, dyeing it brown and mixing it into a legal shipment of another primate.

Endangered tortoises from Madagascar are seized from smugglers by customs officials in Malaysia. Credit: Manan Vatsyayana Getty Images

The sheer variety of species being traded also reduces the likelihood of detection. “There's nobody out there who knows all the birds,” says Eric Goode, founder of the nonprofit Turtle Conservancy, based in New York City. “Tropical fish, unless you get the world's top ichthyologist, they don't know how to identify all those species. In the case of turtles [and tortoises], there are only 340 species on the planet,” but inspectors typically “can't tell a Burmese star tortoise from an Indian star tortoise or one soft-shelled turtle from another.” CITES may ban all trade in a critically endangered turtle or parrot, he adds, but traffickers “just label it as a more common variety” and go on about their business.

Catch or Breed?

Goode and others argue that if the pet trade cares about conservation, suppliers should stop harvesting animals from the wild and focus on breeding them in captivity. “There's a point when you have to walk the walk,” he says. “Let's really stop the importation of wildlife, stop the importation of wild birds, stop the Russian tortoises,” a species from Central Asia commonly sold in U.S. pet stores. “Go to any of these warehouses and see the staggering mortality that occurs every day. Why do you need this constant flow of animals into the U.S. that are caught in the wild?”

Captive breeding could be the answer to the bird trade in Indonesia, where many households already keep captive-bred lovebirds, Wilcove says. A program aimed at increasing availability of inexpensive budgerigars, canaries and other pet-friendly species might help persuade people that they do not “need to own a shama or to buy some of these wild-caught birds that are not suited to living in a cage.” As a child, he adds, he used a recording by “the Pavarotti of the canary world” to train his pet canary to sing. “There's no reason canaries couldn't become fierce competitors” in Indonesian singing competitions, Wilcove observes.

But captive breeding can also be harder than it might seem. In 2014 EcoHealth Alliance, a New York City–based nonprofit, established its EcoHealthy Pets Web site, modeled on the Monterey Bay Aquarium's Seafood Watch, to alert consumers to the best and worst choices in exotic pets. The list emphasizes captive breeding as a way to reduce both health risks and pressure on the natural world. But lack of financial support to expand this program has so far limited the list to just 52 species, not nearly enough to satisfy even many beginning hobbyists.

The pet industry has remained ambivalent about a broad commitment to captive breeding, in part because no one has figured out how to breed many animal groups that are popular as pets. And when they do figure it out, they may find that raising an animal to maturity is far more expensive than simply catching it from the wild. When breeders in the lucrative saltwater aquarium fish trade learned how to rear colorful mandarinfish, for instance, “the mass market didn't want to pay $40 for a captive-bred fish they could get for $12 from wild-caught sources,” Scott Fellman, an aquarium trade retailer, complained in an online forum. “Shame on us, as a hobby, for not doing more to support efforts like this,” he added.

Further complicating matters, many self-styled captive-breeding facilities also replenish their stock from the wild and may thus serve merely to launder the wholesale removal of wildlife from habitats. For instance, the number of purportedly captive-bred Papuan hornbills being exported “far exceeds what breeding facilities can hold or yield, given the species' slow reproductive rate,” conservation geneticist Laura Tensen of the University of Johannesburg reported in a survey of wildlife farming published in 2016 in Global Ecology and Conservation. Likewise, many frog and chameleon species appear to be economically unsuited to breeding programs because of low reproductive success in captivity, and yet, Tensen noted, they “are being traded as pets in their thousands under the guise of captive breeding.”

Credit: Amanda Montañez; Source: “Using Market Data and Expert Opinion to Identify Overexploited Species in the Wild Bird Trade,” by J. Berton C. Harris et al., in Biological Conservation, Vol. 187; July 2015

Even if traders could figure out how to breed all of the species people want as pets in captivity, not all conservationists think that they should. When Australian herpetologists Daniel Natusch and Jessica Lyons made a detailed investigation of the trade in green pythons from Indonesia, all supposedly from captive-bred stock, they found that many facilities did not actually know how to breed reptiles successfully. Some did not even have premises on which to attempt breeding. The researchers estimated that 80 percent of these snakes exported to the pet trade are in fact caught in the wild. But the wild-caught trade in green pythons appeared to be sustainable because of their abundance in the wild.

In such cases, Natusch says, the wild-caught trade may be better for conservation than captive breeding: “You can incentivize people to protect the habitat. If you can harvest these animals sustainably, you can have an income from the forest, and you don't have to cut down the forest.”

Natusch, who works as a consultant to the IUCN, acknowledges that exporters can do horrible things for the trade—for instance, cramming snakes into suitcases and soda bottles to smuggle them through customs. He also agrees that taking snakes from endemic populations restricted to islands or outcrops can pose a threat to their survival. But the trouble with captive breeding, he notes, is that “once you take those animals from the wild, you have completely disassociated” the trade from any reason to care about the natural habitat. In contrast, he says, an entirely illegal trade in green pythons from Indonesia's Raja Ampat archipelago has motivated islanders to keep their forests intact. (A rare yellow color morph makes the snake trade there particularly lucrative.)

Demand and Supply

People who collect rare species are often “convinced they are doing wonderful things for animals” by taking them out of the wild and sheltering them from hunger, predation and other natural threats, says University of Oxford conservation biologist Tom P. Moorhouse, lead author of a 2017 study of consumer attitudes toward exotic pets published in Conservation Letters. He observes that buyers also typically assume “their ethical duties have been taken care of by the time an animal reaches the market.” They have not. “We need a campaign to convince people that this isn't the case and that their choices have a massive effect,” Moorhouse adds. “If there were no demand, no market for wild-caught exotics, there'd be no point paying someone to capture animals from the wild.”

The pet industry has yet to come to terms with the issue of how the trade is affecting animal populations in the wild. Still, it does care about conservation, insists Mike Bober, president of the Pet Industry Joint Advisory Council. “We think that there is a place for wild-caught and captive-bred in most of these communities—the important thing being the methods used for collection,” he says. “When the animals are collected sustainably, especially when they are collected by indigenous people who depend on that for their livelihood, we are proud of that. When they are collected badly, it is a direct problem for our industry. We rely on healthy ecosystems for healthy animals, and without healthy pets, there is no healthy pet trade.”

But healthy ecosystems are vanishingly rare in the human era, and no adequate standards of sustainable collecting exist. Sooner or later pet lovers and the trade will need to face up to that reality and devise better ways of sourcing animals in a world where forests, oceans and other habitats are running empty.