Bolivia's Notorious 'Death Road' Is Now a Wildlife Haven

Imagine inching along a 5-meter (approximately 16-foot) wide dirt road in a heavy truck, looking out your window to get your bearings, and seeing a 100-meter (approximately 328-foot) drop with no guardrail between you and the abyss below. This was a daily experience for drivers on a busy Bolivian motorway so perilous it was nicknamed the "Camino de la Muerte” or “Death Road."

Then, in 2007, the government finally built a much safer replacement. Suddenly, traffic on the dangerous but busy motorway fell by 90%. And, according to a Wildlife Conservation Society (WCS) study published in Ecología en Bolivia this year, the abandoned roadway began to attract a different species of traveler. The “Death Road” took on a second life as a haven for wildlife, including vulnerable and endangered species.

"This study highlights the resilience of wildlife and biodiversity and its capacity to recover if allowed," Robert Wallace, study co-author and director of the WCS’s Greater Madidi-Tambopata Landscape Program, tells Treehugger in an email.

Road of Death

The so-called "Death Road"—otherwise known as the old road to the Yungas—was built in 1930. For almost 80 years, it was the only road connecting La Paz, the seat of Bolivia’s government, with the north of the country, which meant it saw heavy traffic 24 hours a day and emerged as one of the most traveled roads in the country for both light and heavy vehicles. This is despite the fact that it saw an average of 200 accidents and 300 deaths per year between 1999 and 2003.

“The Road was deadly for people because it was a very narrow dirt/mud road, indeed so narrow that in places there is only one lane. In those parts, there are 100-meter drop-offs,” Wallace explains. 

Additional hazards included frequent curves, a lack of guardrails, and heavy rains and fog that would make driving conditions even more treacherous. 

The motorway wasn’t any better for Bolivia’s non-human inhabitants, though in this respect it was less unique. Indeed, from an animal perspective, any busy highway could be considered a “Death Road.” An estimated 194 million birds and 29 million mammals may die on European roads each year, while 365 million vertebrates are estimated to die as roadkill annually in the U.S.

“Highways of whatever kind cause a variety of negative effects–both direct and indirect–on animal life, like the increase in chemical pollution, the displacement of species, death by car and changes in behavior as animals are disturbed by excessive noise and wind turbulence,” the study authors write. 

Noise pollution in particular is a problem for animals like bats, frogs, and birds that rely on sound to communicate. A 2011 study, for example, found fewer birds from a smaller range of species were found near a highway in a protected forest in Costa Rica when traffic noises increased.

This isn’t just a problem for Latin America, of course. A 2009 review of studies looking at how roads and traffic affect animal abundance found five times more studies detailing negative impacts than positive ones. Animals also steered clear of the “Death Road.” Rangers at the nearby Cotapata National Park and Natural Integrated Management Area saw no evidence of wild mammals by the road between 1990 and 2005 and very little evidence of birds.

Road of Life

Everything changed in 2007 with the construction of the Cotapata-Santa Bárbara highway. 

"The new road is an asphalt modern road with two lanes in all places and railings, etc.," Wallace says.

This has made things much safer for humans. As traffic on the road plummeted by 90%, deaths and accidents fell as well. Now people mainly use the path for activities related to ecotourism like mountain biking and bird watching. The latter is indicative of another transformation.

"[T]he wildlife has come back," Wallace says. "From road of death to road of life."

To actually document these changes, the researchers set up 35 camera traps along 12 kilometers (approximately 7.5 miles) on and around the road and in a settlement in the park called Azucarani about 1.8 kilometers (approximately 1.1 miles) away. During November and December of 2016, the researchers managed 515.43 traps per night for a total of 14,185 photographs. These images were 7% of wild mammals, 9% of birds, 1% of domestic animals, and 83% without animals. 

Overall, the researchers counted 16 different species of medium and large mammals and 94 different species of wild birds. The most common sightings were 

1. The white-throated quail-dove (Zentrygon frenata), considered a species of Least Concern by the International Union for Conservation of Nature (IUCN) Red List.
2. The Peruvian dwarf brocket (Mazama chunyi), a small deer that is considered Vulnerable by the IUCN.
3. The Andean guan (Penelope montagni), a high-elevation bird species of Least Concern that eBird describes as “chickenlike.”
4. The mountain paca (Cuniculus taczanowskii), a guinea-pig-like rodent that is considered Near-Threatened by the IUCN.
5. The oncilla cat (Leopardus tigrinus), which is also called the northern tiger cat and is considered Vulnerable by the IUCN.

Another notable find was the endangered black and chestnut eagle (Spizaetus isidori). Finally, the scientists were excited by evidence of a vulnerable species of bear that wasn’t actually photographed along the road, but had been spotted nearby and also left some of its droppings in the study area: the Andean bear. 

“The Andean bear is the very symbol of the cloud forests and tropical montane forests and mountain grasslands of the Andes,” Wallace says.

Overall, the study is the beginning of understanding the biodiversity of the new “road of life.”

“This work is the first carried out on this road and therefore contributes valuable information on the richness and abundance of mammals and birds, being relevant as a baseline,” the study authors write. 

Resurrecting Roadways 

The study is a sign of hope that roads don't have to be deadly for animals. It comes as there is growing interest around the world in constructing special wildlife crossings and corridors to help animals navigate around human traffic. These crossings have proven to be effective. A combination of overpasses, underpasses, and fencing reduced animal-and-vehicle crashes by 80% at Trappers Point in Wyoming, for example.

The transformation of the "Death Road" shows what can happen when drivers largely ditch a route, but WCS is also trying to make Bolivia’s still-trafficked roads safer for animals.

"In Bolivia, WCS is working with the Bolivian Roads Authority to assist them in the development of policies and techniques with which to try and minimize the impact of new roads and the ongoing improvement of major thoroughfares," Wallace says. "We are also generating information and testing emerging methodologies to identify priority wildlife corridors along roads with are scheduled for forthcoming improvements."