A new study by the Wildlife Conservation Society (WCS) reports that a notoriously unsafe road in Bolivia nicknamed “Camino de la Muerte” or “Death Road” has become a surprising haven for wildlife since traffic has decreased by 90 percent due to construction of a nearby, safer roadway. The study is published in the journal Ecología en Bolivia.

The team set up 35 camera traps along 12 km of the road and its surroundings, as well as in the vicinity of Azucarani, a small settlement in the Cotapata National Park and Natural Integrated Management Area. They recorded 16 species of medium and large mammals and 94 species of wild birds. Some of the mammals included dwarf brocket deer (Mazama chunyi), mountain paca (Cuniculus taczanowskii) and oncilla cat (Leopardus tigrinus). Birds included endemic species such as Bolivian brush finch (Atlapetes rufinucha), light-crowned spinetail (Cranioleuca albiceps), and rufous faced antpitta (Grallaria erythrotis), as well as Vulnerable species including hooded tinamou (Nothocercus nigrocapillus) and Endangered black and chestnut eagle (Spizaetus isidori).

The Death Road was opened in 1930, and over the years it became one of the busiest routes in the country for light and heavy vehicles, as it was the only land access between the La Paz and northern Bolivia. The narrow road had many curves, 100-meter cliffs, and a lack of guard rails. This, coupled with continuous rains, muddy conditions and dense fog created a deadly recipe for drivers and passengers. It is estimated that between 1999 and 2003 an average of 200 accidents occurred annually, resulting in 300 deaths per year.

For decades, Bolivians clamored for a solution to this high fatality rate. Then in 2007 a new, much safer asphalt road opened on the opposite slope, called the Cotapata-Santa Bárbara highway. Thanks to this new road, the vehicular flow on the Death Road decreased by more than 90 percent, and with it, the number of accidents and deaths.

Additionally, it had a positive impact on the surrounding biodiversity. Roads of any kind cause direct and indirect negative effects on wildlife, such as animal mortality through roadkill, loss of connectivity of their populations and disturbances in animal behavior and in the abundance of their populations caused by excessive noise, wind turbulence and increased chemical pollution. For example, species such as frogs, bats and birds, which rely on sound for communication, are often profoundly affected by noise, which interferes with the vocalizations they use for territorial defense or courtship.

Between 1990 and 2005 park rangers saw little evidence of mammals around the Death Road. However, this situation has improved substantially in recent years.

Said Guido Ayala Crespo, WCS Scientific Research Coordinator and the lead author of the study: “This study contributes valuable information to the knowledge of the richness and abundance of mammals and birds along this thoroughfare, providing a baseline for future long-term monitoring. The results also demonstrate the resilience of nature in the wild, and the importance of connectivity for protected areas.”