Every year, thousands of animals are killed on Nevada’s roads. But the problem isn’t unique to the state. Costa Rica is also facing a similar problem. To help reduce these collisions, efforts are underway to build wildlife crossings in both.
The rainforest in Sarapiquí comes alive. Rain drips onto the forest floor; birds fly overhead; frogs croak; and howler monkeys bark.
Although Sarapiquí is located within the rainforest, it’s surrounded by urban development, and with that comes cars.
Researchers estimate that in Costa Rica, about four animals die on the highway every hour.
Located in the country’s capital, San José, is the Toucan Rescue Ranch, a rehabilitation center for animals that focuses on education and conservation. Guide and former volunteer, Pablo Bonilla has seen the consequences of animal vehicle collisions firsthand.
“We just recently, a couple of months ago, got a baby howler monkey, that the mom got hit by a car, so the mom passed away,” he said.
Bonilla said that outside of rescued pets, vehicle collisions are one of the most common reasons animals arrive at the sanctuary.
Coatis, monkeys and sloths are frequently struck by vehicles, especially near Route 32, one of the country’s busiest highways. Route 32 winds through mountainous rainforest near Cerro de la Muerte — Hill of Death.
As development expands deeper into the forest, more animals are being forced onto roads. Naturalist, Reyder Mesen, used to work for an organization that supported various conservation efforts. He has seen the impact of the wildlife bridges the organization helped construct.
“Hay muchos animales que necesitan cruzar los lugares o otras partes de bosque y habiendo carreteras por las calles es un obstáculo para ellos,” he said. “Y realmente lo vimos, hay monos utilizando los puentes aéreos, los puentes colgantes.”
“There are many animals that need to cross these areas or other parts of the forest, and the presence of roads poses an obstacle for them,” he said. “And we actually saw it, there are monkeys using the aerial bridges, the suspension bridges.”
Mesen said animals need to be able to get from place to place in the rainforest. Because of roads being in areas where animals need to cross he has seen how animals, like monkeys, use the aerial bridges instead.
For people like naturalist Geremi Telecaluna who grew up in Sarapiqui, roadkill is a familiar sight.
“Well, I've never seen any cat, I mean wild cats in my life, but I've seen them a lot on the roads, dead,” he said.
Animals need to travel through the forest for different reasons — including to find food, Mesen said.
While Northern Nevada’s desert ecosystem may look different from the rainforest, with its wider roads and dry open landscapes, the challenge is similar. Roads still cut through animals’ natural migration routes.
Every year in Nevada, thousands of animals are hit by vehicles according to the Nevada Department of Transportation (NDOT). Since 2010, the state has built 80 wildlife crossings.
NDOT tries to integrate these crossings into the natural environment, said Nova Simpson, wildlife crossing program manager.
“We've actually had bighorn sheep bedded down underneath the bridges for shade, so it's kind of created its own little micro habitat,” she said.
Simpson said the goal is to keep both animals and drivers safe.
“We have everything from some of the largest overpasses in the US along I-80 to some of the smallest underpasses for desert tortoise, so we have a variety of structures across the landscape already in place, and those structures have been really effective at reducing collisions,” she said.
These structures have had about an 80 percent success rate, Simpson said.
In 2023, Nevada lawmakers approved an additional $5 million for wildlife crossing projects.
Unlike Nevada, the government in Costa Rica hasn’t provided much support, Bonilla said.
“These past few years have not been like the best government about wildlife or taking care about the wildlife, so that is why we haven't seen too much about it,” he said, referring to government support for wildlife crossings.
Costa Rican lawmakers are considering legislation that conservation groups say could expand wildlife crossing protections. The initial proposal passed a first round vote in April, but uncertainty still lingers as the bill still needs to pass a second round.
In Costa Rica, Bonilla said the roads are not going away, so humans have to be the ones to adapt.
This story is in partnership with the Hitchcock Project for Visualizing Science and the Reynolds School of Journalism.
