In 2011, Kendra McSweeney traveled to the La Mosquitia region of eastern Honduras, where she’d worked as a rainforest researcher in the mid-1990s. The region during her time there was largely pristine, with unbroken expanses of jungle. On her return, huge areas were being cleared for pasture. Animals, including deer, paca and tapirs, fled ahead of the cutting, sometimes right into indigenous villages. “I saw patterns of land use and settlement that were completely unlike anything else I’d seen before,” says McSweeney, a geography professor at Ohio State University. “Clear-cutting, ranching and agriculture were utterly transforming communities once surrounded by tens, if not hundreds, of kilometers of pristine rainforest.”

Experts say the drug trade, in large part, is driving the trend. In the last seven years, the Mosquito coast of Honduras and the Petén region of Guatemala have become principal destinations for U.S.-bound Colombian cocaine. Powerful drug gangs have taken root, displacing indigenous peoples from their homes and clearing huge areas of wilderness to launder their profits in land speculation, cattle ranching and African-palm cultivation.

“... [T]he trafficking of drugs [principally cocaine] has become a crucial—and overlooked—accelerant of forest loss [in Central America],” says an article, published Jan. 31 in Science magazine, by McSweeney and six other authors from universities in the United States and Germany.

Central America’s role as a prime drug trafficking hub is a result of what analysts call the “balloon effect,” whereby repressing illegal activity in one area results in that illegal activity growing in another, just as one end of a balloon expands when the other end is squeezed. During the late 1990s and early 2000s, cocaine en route to the United States typically travelled by plane or boat from Colombia to Mexico, sometimes making a stopover in the Dominican Republic or other parts of the Caribbean on the way. Once in Mexico, the drugs were put on board trucks for the journey northward.

But a crackdown on cartels by Mexican security forces, begun in 2006, and stepped-up drug interdiction in the Caribbean, have prompted drug traffickers to change routes. Cocaine leaving Colombia for the United States now travels first to Central America. Even cocaine headed to Europe passes through the region, according to law-enforcement officials.

Corrosive effect

Experts say weak governments, corrupt officials and porous borders in Central America have contributed to the shift, which has had enormous repercussions in the region. To ease the flow of drugs, Mexican cartels have forged criminal alliances with political, military, and rural elites in Central America. Assassination has become routine. Honduras and Guatemala now rank among the ten most murderous nations in the world, with Honduras topping the list at 82 murders per 100,000 inhabitants in 2010, according to the United Nations Office on Drugs and Crime.

Deforestation has shot up as traffickers build landing strips, clear transshipment areas and establish ranches and farms to launder money. Between 2007 and 2011, the average annual loss of forest cover in eastern Honduras tripled to around 65 square kilometers (25 sq miles) per year. Deforestation rates in parts of Guatemala are even higher. In Petén’s Laguna del Tigre National Park and in protected areas of the municipality of Sayaxché—both overland drug routes to Mexico—woodland is being lost at annual rates of 5% and 10%, respectively, according to the Science article.

Environmental groups are alarmed, but say there is little they can do. Locals, including ranchers who have grown rich collaborating with traffickers, have the means and power to clear the wilderness and appropriate illegally acquired properties. Drug gangs see forest cutting as a natural offshoot of their trade: a way to launder illegal earnings through the establishment of new farms and ranches that can then be sold off to corporate interests, experts say.

“Land grabbing and deforestation are means by which organized crime groups in Central America gain control of strategic areas for drug transit,” says Marco Cerezo, general director of FundaEco, a Guatemalan nonprofit focused on sustainable development and establishing protected areas. “Because of the lack of governmental presence in protected and border areas, those groups can act with impunity.”

The Río Plátano Biosphere Reserve is a stark case. A Unesco World Heritage Site since 1982, the 800,000-hectare (2-million-acre) expanse of tropical forest, pine savannah and mangrove swamp in the heart of La Mosquitia has long been considered one of Central America’s most biodiverse places. It provides habitat for 39 species of mammals and 377 species of birds on the edge of the Caribbean Sea.

Unwelcome influx

But since drug groups arrived in the mid-2000s, Río Plátano has taken on a new cast. Land values in the protected area have more than doubled, and entire indigenous villages have fled under threat from traffickers. Deforestation has soared. In 2006-11, nearly 40,000 hectares (99,000 acres) of the reserve’s forest were lost, says a study by the Honduran state-run Institute of Forest Conservation (ICF).

In Laguna del Tigre Park, which borders Mexico, deforestation by narco-underwritten cattle ranching grew so extreme by 2010 that Guatemala’s president at the time, Álvaro Colom, ordered troops into the park to expel the drug traffickers and their herds. “I don’t want to ever see another head of cattle there because I’m going to butcher it and distribute it among the poor,” the president told the press on the eve of the operation.

The destruction continues apace in the 334,080-hectare (825,000-acre) protected area, home to one of the scarlet macaw’s (Ara macao) most important Central American nesting sites and to endangered species such as the Mesoamerican river turtle (Dermatemys mawii).

Experts see no easy ways to reverse Central America’s cycle of drug-trafficking and deforestation. Strengthening the budgets and resources of park and environmental authorities and empowering indigenous organizations to resist the traffickers might help, they say. But drug-policy reform to drive down demand is also warranted. “Drug policy is conservation policy,” the authors of the Science article write. “Rethinking the war on drugs could yield important ecological benefits.”