Once, in Madagascar, I ordered lunch at an outdoor restaurant. A cluster of street kids gathered on the other side of the railing, plainly famished, to watch me eat. Some beany dish, if I recall correctly, with bits of chicken in it. It might even have tasted good under other circumstances.

In any case, I ate. It’s too easy to get overwhelmed by beggars in places like that, and maybe I thought it would be rude to the restaurant owner to indulge them. Maybe I was also hungry, or at least hungry by American standards, after two weeks in the bush eating a lot of rice. Or maybe I was just callous. In any case, what happened next stunned me: I got up to leave, and the kids instantly reached over the rail to grab my plate and lick it clean.

Madagascar is one of the poorest countries on Earth and always seemingly getting poorer. But like most visitors, I was there to look at lemurs and other wildlife, not poverty. In particular, I saw sifaka lemurs, with their stark, staring, reddish-brown eyes, and their artful way of leaping from branch to branch like ballet dancers in perfect partnership with the trees. They were gorgeous. The idea of killing and eating them seemed like an abomination, especially since lemurs occur nowhere else in the world, and 94 percent of the 110 or so lemur species are now threatened with extinction.

But a new study in the journal Biological Conservation makes clear that understanding and addressing the poverty is the critical point if you want to have any chance of saving Madagascar’s lemurs from extinction. Roughly 70 percent of the 20 million Malagasy get by on less than $1 a day. Malnutrition afflicts more than a third of the population, and it is especially destructive for children. In these circumstances, you and I might just hunt lemurs too. And all the solutions typically pursued by conservationists—educating people about extinction, introducing the economic benefits of ecotourism, and providing access to some alternative animal food—don’t work.

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For her study, lead author Cortni Borgerson, a physical anthropologist at the Harvard T.H. Chan School of Public Health, conducted painstakingly detailed interviews with the residents of a village in northeastern Madagascar. It’s one of 36 villages bordering the Masoala National Park, part of a peninsula of the same name that is a United Nations World Heritage Site. Ten species of lemurs live there. Half are endangered or critically endangered, and 90 percent are threatened.

Borgerson has worked there for the past nine years and has earned enough local trust (and patience) that at least one person from each of the village’s 36 households acquiesced to a 600-question interview. (She speaks the local dialect of Betsimisaraka.) Her ambition was to test 11 different hypotheses about who hunts lemurs and why they hunt them, as well as what measures might get them to stop.

Teaching them that lemurs are endangered made no difference, it turned out. “The people who hunt lemurs do not believe they are endangered anyway, they think it’s laughable,” said coauthor Margaret McKean, a political economist at Duke University. That’s partly because lemurs that feel threatened elsewhere tend to move into nearby protected areas. “So people there may say the population is increasing, everything is fine.”

It also did not stop people to know that hunting is illegal and can mean severe punishments. Family circumstances obliged lemur hunters and trappers to take that risk. Likewise, employment in ecotourism made no difference. The study found that “households with more members working in ecotourism also had slightly more lemur trappers,” possibly because “community-based ecotourism as actually practiced can also fail to improve human livelihoods.”

But the most disheartening finding was that providing an alternative animal protein source also failed to prevent lemur hunting. In India, the development of poultry stands in almost every village has been an important factor in reducing pressure on wildlife, according to conservationists I spoke with there. But in Madagascar, many families lack cash money or other means to invest in poultry. Moreover, people there eat poultry and lemurs in different seasons, and they may prefer the taste and relative fattiness of lemurs.

So if all these methods make no difference in ending the killing of lemurs, what will? Borgerson found that just three factors predicted the likelihood that a household will turn to lemur-eating: the number of sick days in the household during the prior month, the size and materials of the house, and low body mass index in the children, all marks of extreme poverty.

The results pose a direct challenge to conventional thinking in the conservation community. The standard refrain among conservationists is that they need to be “talking to the local people,” said coauthor Laurie Godfrey, a University of Massachusetts paleontologist who has worked in Madagascar since the 1970s. “But what they mean is talking at the local people, rather than embracing the local people,” she said. Borgerson embraced the community, but her work does not yet provide any logical way forward. “This is really complicated, really messy, and the quick things you think up as solutions aren’t,” added McKean. Essentially, what we now know is that nothing we know seems to work—and that poverty is critically important.

Borgerson, meanwhile, is back in Masoala pursuing her research. The question is not just whether she can come back with some practical way forward—but whether there will be any lemurs left in the wild when she does.