The baby blue and orange-spotted tokay gecko—whose creaky calls of to-kay provided its onomatopoeic name—have always been ubiquitous throughout Southeast Asia, southern China and India. The wall-climbing reptiles often reside in restaurants, gardens and homes, where they help control insect pests.

In recent years, though, they have begun to be traded by the millions on the international market—and evidence is emerging that the species is in quick decline, says Vincent Nijman, an anthropologist at Oxford Brookes University in England. Few scientists have undertaken studies of gecko population trends, but teams have confirmed declines as high as 50 percent in China, Vietnam, Thailand, Myanmar (formerly Burma), Indonesia, the Philippines and Bangladesh. Anecdotally, “many people say that where they could hear tokays in their backyards 10 to 15 years ago, they are no longer there,” Nijman says.

While the focus of efforts to rein in the wildlife trade often falls on rarer, better-loved creatures such as elephants, rhinoceroses and tigers, thousands of more quotidian species are commercially sought after as well. No one knows how many tokay geckos are captured each year for trade, yet the figure is certainly a million or more, Nijman says. A small percent wind up in Europe, Japan and the U.S. to be sold as pets. The vast majority, however, go to China for use as traditional medicine ingredients to treat asthma, diabetes, eczema, erectile dysfunction, and more. No scientific evidence supports the geckos’ efficacy as a medical treatment.

Such trade can be sustainable if legally and scientifically managed, yet if left unchecked, it can quickly spin out of control and threaten even common species with extinction. The recent observations of tokay gecko declines have some scientists and conservationists concerned that the lizards could go the way of the bison, passenger pigeon and saiga antelope—all species that were once exceedingly common but experienced massive population collapse—and in the case of passenger pigeons, extinction—as a result of overhunting and other human pressures.

“People take for granted common species because they’re common,” Nijman says. “They don’t care about them, don’t worry about them, exploit them as they please. And then suddenly, one or two generations later, we realize that they’re no longer common.” It is only after the fact, he says—when we see the impacts to the environment caused by the loss of these species—that we grasp their importance.

No international rules currently protect geckos from unsustainable levels of trade, but that could soon change. At the end of this month, the 183 parties who have signed the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) will vote on whether to add geckos to the list of species regulated by that treaty, which is meant to ensure that international trade does not wipe out plants and animals.

The new protections are not guaranteed, however. China and Indonesia, the primary countries driving tokay gecko trade, oppose the move. “Of course there are some countries that are not too happy about this,” says Gerald Benyr, a zoologist and member of the Austrian CITES team, which—along with its colleagues in the European Union, India, the Philippines and the U.S.—proposed including tokay geckos in the treaty.

A number of Southeast Asian nations export geckos to China, but Indonesia, the CITES proposal notes, seems to be the biggest player, followed by Thailand. Each year, the Indonesian government approves export quotas for more than a million geckos labelled as bred in captivity. Yet a 2015 investigation conducted by TRAFFIC, a wildlife-trade-monitoring organization, indicated that most, if not all, of Indonesia’s “captive bred” geckos are actually caught in the wild. According to Benyr, other gecko species are still present in places where tokays have declined or disappeared, indicating that excessive targeted hunting is likely to blame in Indonesia and elsewhere in the lizard’s range.

Some capture and sale of wild tokay geckos is allowed, and officials issue an export quota for them, which is based on requests from traders. Requested quotas undergo a scientific review conducted by government and academic scientists to confirm they will not deplete the population in question. Data are often lacking about species’ conservation statuses, however, especially for smaller animals that do not garner much public attention, says Ani Mardiastuti, a wildlife ecologist at IPB University in Indonesia, who often assists in setting quotas. When information about a species is scant, “we use common sense,” she says. “For example, if it’s a big province with lots of forest still there or if it’s a species that breeds easily and is not endangered, we say, ‘Okay, we will allow them to harvest that specific amount.’”

Traders also take part in quota-setting meetings, and their wishes are taken into consideration. “The government is, of course, an institution. And any institution in Indonesia always has a target to generate some revenue that doesn’t come from tax,” Mardiastuti says. “Every time a trader wants to do an export, they need to pay some money as a fee, which generates some revenue.” Nijman, who has sat in on quota-setting meetings, says, “It is the traders’ requests that drive the quota setting.”

Last year, Indonesia set its export quota for tokay geckos at 25,000 animals, but this year, the figure jumped to 1.8 million for just three provinces on its island of Java. Nijman says he was shocked to see the number, which was released this past July. “It’s so completely over the top,” he says. He suspects that the increase comes in anticipation of the CITES decision. “It’s a very different negotiation position if you start at 1.8 million rather than 25,000,” he says, describing the strategy as “set the numbers very high now, and then we can lower them to show our good intentions.”

Amir Hamidy, a herpetologist at the Indonesian Institute of Sciences in Jakarta and a member of Indonesia’s CITES team, asserts the quota increase was not related to the CITES proposal. Instead, he says, it is an experiment to see if gecko populations can sustain higher levels of harvesting. “I don’t think it will be a problem for the species, because it has a very wide distribution, and it’s categorized as having a good ability to adapt and reproduce quickly,” he says. A baseline study he started in Java last year, Hamidy adds, suggests that harvesting the geckos can be sustainable. “I’m living in Java, and the species is very common in every house and around human settlements,” he says.

Benyr cautions, however, that tokay geckos’ tendencies to live around people could contribute to a misperception about the species’ abundance: “In many places, tokay geckos are easily encountered in the vicinity of humans. But if you go into the forest, the species is definitely not as common or is even quite rare.”

If CITES representatives vote to add geckos to the convention, then Indonesia and other countries must start monitoring and reporting all international trade of the species and scientifically verify that it does not harm populations. CITES officials will also be able to investigate captive breeding facilities to ensure that animals are not simply being laundered from the wild.

Those added precautions would help not only tokay geckos but also the ecosystem as a whole, Nijman says. The lizards may be small and “not very sexy,” he says, but as a common, widespread species that acts as both predator and prey, they play an outsize role in ecosystems. “In general, we should actually care more about the common species than the rare ones, as it is the common species that make the system function,” Nijman says. When bison disappeared from the American plains in the 19th century, for example, and when the passenger pigeon went extinct in 1914, the impacts on North American ecosystems were profound. “The loss of the dodo is sad, but the loss of the passenger pigeon is a tragedy,” he says.