Imagine driving down a 5 meter (about 16 foot) wide dirt road in a heavy truck, looking out the window for orientation and seeing a 100 meter (about 328 foot) drop with no guardrails between you and the abyss below. -below. It was a daily experience for drivers on a busy Bolivian highway so perilous it was dubbed the “Camino de la Muerte” or “Road of Death.”
Then, in 2007, the government finally built a much safer replacement. As a result, traffic on the dangerous but busy highway dropped by 90%. And, according to a study by the Wildlife Conservation Society (WCS) published in Ecology in Bolivia this year, the abandoned causeway began to attract a different kind of traveler. The ‘Road of Death’ has taken 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 ability to recover if allowed,” said Robert Wallace, study co-author and director of the Greater Madidi-Tambopata Landscape Program. from WCS, to Treehugger in an email.
road of death
The so-called “Road of Death” – otherwise known as the Old Yungas Road – was built in 1930. For nearly 80 years, it was the only road linking La Paz, seat of the Bolivian government, in the north of the country. , meaning it experienced heavy traffic around the clock and became one of the busiest roads in the country for both light and heavy vehicles. And this despite the fact that it recorded 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, in fact so narrow that there is only one lane in places. 100 yards,” says Wallace.
Additional hazards included frequent turns, a lack of guardrails, and heavy rain and fog that would make driving conditions even more dangerous.
The highway was no better for the nonhuman inhabitants of Bolivia, though in that respect it was less unique. Indeed, from an animal point of view, any busy highway could be considered a “road of death”. An estimated 194 million birds and 29 million mammals may die on European roads each year, while 365 million vertebrates are estimated to die each year in the United States.
“Highways of any kind cause a variety of negative effects – direct and indirect – on animal life, such as increased chemical pollution, displacement of species, car fatalities and changes in behavior as animals are disturbed by excessive noise and wind turbulence. write the authors of the study.
Noise pollution in particular is a problem for animals like bats, frogs and birds that depend on sound to communicate. A 2011 study, for example, found that fewer birds of a smaller range of species were found near a highway in a protected forest in Costa Rica when traffic noise increased.
This is not just a problem for Latin America, of course. A 2009 review of studies examining how roads and traffic affect animal abundance found five times as many studies detailing negative impacts as positive ones. The animals also avoided the “road of death”. Between 1990 and 2005, rangers in the Cotapata National Park and Natural Integrated Management Area saw no signs of wild mammals by the roadside and very few signs of birds.
road of life
Everything changed in 2007 with the construction of the Cotapata-Santa Bárbara highway.
“The new road is a modern asphalt road with two lanes throughout and railings etc,” Wallace explains.
It made things much safer for humans. While traffic on the road has fallen by 90%, fatalities and accidents have also fallen. Now people mainly use the trail for ecotourism related activities like mountain biking and bird watching. The latter is indicative of another transformation.
“[T]he wildlife has returned,” says Wallace. “From the road of death to the road of life.
To actually document these changes, the researchers set up 35 camera traps 12 kilometers (about 7.5 miles) up and around the road and at a settlement in the park called Azucarani about 1.8 kilometers (about 1.1 miles) away. . In November and December 2016, researchers managed 515.43 traps per night for a total of 14,185 photographs. These images were 7% wild mammals, 9% birds, 1% domestic animals, and 83% no animals.
In total, the researchers counted 16 different species of medium and large mammals and 94 different species of wild birds. The most frequent observations were
- The white-throated dove (Zentrygon frenata), listed as a species of Least Concern by the International Union for Conservation of Nature (IUCN) Red List.
- The peruvian dwarf broom (Mazama Chunyi), a small deer considered Vulnerable by the IUCN.
- The Andean guan (Penelope montagni), a high-altitude bird species of Least Concern that eBird describes as “chicken-like”.
- The mountain paca (Cuniculus taczanowskii), a guinea pig-like rodent considered Near Threatened by the IUCN.
- The oncilla cat (Leopardus tigrinus), also called the northern tiger cat and considered vulnerable by the IUCN.
Another notable find was the endangered black-chestnut eagle (Spizaetus isidori). Finally, scientists were excited about the evidence of a vulnerable species of bear that was not actually photographed along the road, but was 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, montane rainforests and montane grasslands of the Andes,” says Wallace.
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 route and therefore provides valuable information on the richness and abundance of mammals and birds, being relevant as a reference,” write the authors of the study.
Resurrect the roads
The study is a hopeful sign that roads don’t have to be lethal to animals. This comes amid growing global interest in building special wildlife passages and corridors to help animals bypass human traffic. These crosses have proven effective. A combination of overpasses, underpasses and fencing has reduced collisions between animals and vehicles by 80% at Trappers Point in Wyoming, for example.
The ‘death road’ transformation shows what can happen when drivers largely abandon a route, but WCS is also trying to make Bolivia’s still busy roads safer for animals.
“In Bolivia, WCS is working with the Bolivian Roads Authority to help them develop policies and techniques to try to minimize the impact of new roads and the continued improvement of major arteries,” Wallace said. “We are also generating information and testing emerging methodologies to identify priority wildlife corridors along roads with planned upgrades.”