There is a sound that defines the Costa Rican jungle before dawn: a deep, resonant roar that can carry for five kilometers through the forest canopy, announcing the presence of one of our country’s most recognizable wildlife species. The mantled howler monkey, with its jet-black fur, russet back, and powerful vocal anatomy, is part of Costa Rica’s natural identity, alongside the quetzal and the sea turtle. It is also disappearing, one electrocution at a time.
The Last Howl, known in Spanish as El Último Aullido, is a 52-minute impact documentary now in production that places this crisis at the center of a broader story about development, biodiversity, political will, and what Costa Rica’s environmental reputation means when tested by rapid coastal expansion and uninsulated power lines.
The film follows three central figures whose work connects to the same crisis from different angles. Dr. Oscar Chaves is a biologist and primatologist who has spent years studying howler monkey behavior and population dynamics in the wild. Dr. Martha Cordero is the lead veterinarian at Las Pumas Wildlife Rescue Center, where injured and orphaned howler monkeys regularly arrive with burns so severe that survival is uncertain even with medical intervention.
Inés Azofeifa, a researcher with SalveMonos, represents the Costa Rican NGO that has been tracking and documenting howler monkey electrocutions for a decade. The organization estimates that about 80% of monkeys that suffer electrocution die from their injuries.
The mechanism of death is simple and devastating. Howler monkeys move through the forest canopy using their four limbs and prehensile tails. As deforestation and coastal development fragment their habitat, the gaps between trees grow wider, forcing the monkeys to use electrical infrastructure to cross them.
When an animal simultaneously contacts a live wire and a grounded cable or structure, the resulting electrocution can kill instantly or leave the monkey with catastrophic burns, amputations, and neurological damage. SalveMonos has warned that, at current rates, Costa Rica could soon record at least one howler monkey electrocution death per day.
The geography of the crisis closely follows the geography of Costa Rica’s tourism boom. Guanacaste, the Pacific coast province that has attracted major foreign investment, luxury development, and new electrical infrastructure over the past two decades, is also where the howler monkey electrocution crisis is most severe.
The documentary centers on Punta Cacique in Guanacaste and the local electrical substation that has become a focal point in the conflict between development pressure and wildlife survival. Natalia García Fallas, a resident of the Lagartillo community, is also featured, adding the human side of a conservation fight that has become a community issue as well.
Laura Jiménez, an environmental lawyer at Mística Legal, brings the legal and policy dimension into the story. Costa Rica has laws meant to protect wildlife. The question raised by the film is if those laws are being applied and enforced in communities where infrastructure and biodiversity collide every day.
Directed by Lucas Zañartu Bravo, the Costa Rican-Chilean co-production is currently about 80% through its first cut, meaning a finished version and festival run are nearing. Impact documentaries of this kind are designed to push policy change, not simply document a problem.
The film’s stated goals include transforming the political and social spaces that define Costa Rica’s relationship with wildlife, suggesting that the finished documentary will be used as a tool in active policy efforts as well as a cultural project.
The howler monkey has been listening to humans move into its territory for decades. With The Last Howl, a small team of scientists, advocates, and filmmakers is giving the monkey’s side of the story a voice loud enough to reach the people who could change the outcome.
More information about the documentary and its final editing campaign is available at thelasthowl.com.
