In Costa Rica, electrocution on power lines is a leading cause of wildlife death - mostly because howler monkeys keep mistaking bare wires for vines. It’s a tragic case of mistaken identity, and the monkeys are losing.
Peque, a small black howler monkey at a rescue centre in Nosara, arrived last year after being zapped alongside her mom, who didn’t make it. “Her tail and hands were burned,” says veterinarian Francisco Sánchez. The centre logged 108 electrocuted animals in 2025, with howler monkeys making up 90% of cases. Sánchez blames the rising body count on development: new houses, restaurants, and hotels are sprouting like invasive weeds, and the power lines are following.
But hope arrives via the constitutional court. In January, it ruled that the state-owned Costa Rican Electricity Institute (ICE) and the Ministry of Environment and Energy (MINAE) had failed to protect wildlife from uninsulated lines in Nosara. The court gave them six months to fix the problem. The ruling follows a campaign called This Is NOT Pura Vida - a dig at the country’s trademark optimism - launched by 20 conservation groups.
Gavin Bruce, CEO of International Animal Rescue, says the ruling could have nationwide teeth. “We will now monitor the implementation and consider how best to scale these protections across the entire country,” he says. In Costa Rica - apparently the only country that bothers to log such things - electrocution is one of the top wildlife killers, with 6,262 cases between June 2022 and June 2023.
MINAE claims it has already implemented measures, but environmental consultant Justo Martín Martín notes that global data on mammal electrocutions is thin. “There are few systematic studies but abundant evidence the problem is global,” he says, citing records from tropical forests in America, Africa, and Asia. In South Africa, 432 mammals were killed on power-line towers between 1997 and 2019, including lions. In Kenya’s Diani, 370 primate electrocutions occurred between 1998 and 2016.
The core issue: fragmented forests. “Monkeys perceive power lines as pathways connecting forest patches,” says Martín. “To them, a power line is essentially a line of connected trees.” So they climb, get fried, and fall - often into traffic or dog attacks. The fix: insulated cables or underground lines, plus artificial canopy bridges.
Sánchez, standing in the rescue centre’s treatment room, is cautiously optimistic. “I’m really happy we have a ruling that says it needs to be addressed,” he says. “But it needs to be implemented across the rest of the country.” A three-year action plan from MINAE and ICE is due by June. “Even in a small place like Nosara, there’s a lot of work that needs to be done,” he adds. “A lot of stakeholders that need to get together.” In other words: the monkeys are watching, and they’re not amused.