If you pause and listen under the lush canopies of the Chachagua Rainforest Hotel in Costa Rica, you might just hear one of the loudest land animal calls in the natural world. These otherworldly calls, echoing out through the forest, belong to howler monkeys.
Howler monkeys are one of Central America’s most abundant monkey species and the largest New World monkeys.
True to their name, howler monkeys produce a thunderous vocalization that echoes through dense jungle foliage, signaling territory, greeting the morning sun, and communicating with far-off rivals. The calls sound like a loud whooping bark or roar, and you can expect to hear other groups howl back in response.
In this article, we’re spotlighting this iconic resident of the Chachagua Rainforest Reserve!
Howler monkeys, belonging to the genus Alouatta, are expertly adapted to thrive among the treetops of the rainforest canopy. These mammals have a prehensile tail that acts as an extra arm, enabling them to grip or hang from branches.
While they can forage for any plant material like fruits, nuts, and flowers, they are primarily folivorous, favoring young leaves for their sweetness and lower toxin levels. These leaves also require less energy to digest, which is handy for a species that spends much of its time resting.
Most of the water they consume comes directly from the foods they eat, giving them even less of a reason to have to be active. In fact, howlers are diurnal, but move around or socialize for only about 45 minutes each day, conserving their energy and lounging in the treetops between feedings.
After a visit to Chachagua Rainforest Hotel, most visitors can mimic the howler monkey’s guttural call, as they so often hear to mark the start and end of the day.
Mantled howlers, called mono congo in Costa Rica, can weigh up to 20 pounds and typically have black fur. They are also noted for a brown or golden-colored mantle that is formed by long hairs along their flanks and back.
Despite howlers’ rather laid-back lifestyle, their vocalizations are anything but gentle. Their hyoid bone (at the top of their neck beneath the chin) is hollow, which is how they can make calls that can be heard miles away, even through the dense rainforests.
They also have an oversized larynx and throat that balloon outward, amplifying the males’ deep, echoing calls that can travel up to three miles. These mighty howls reverberate through the Chachagua Rainforest at dawn and dusk, letting rival troops know where each territory begins and ends.
Conversely, females emit loud wails or groans when distressed or separated from an infant, but these sounds have far less range.
Howler monkeys typically live in troops of four to nineteen members, occupying home territories from 3 to 25 acres in size. Males and females often leave their groups before reaching adulthood, which means troop members tend not to be closely related.
Within these small communities, howlers spend most of their day dozing on branches — often using their muscular tails for added support. This slower-paced lifestyle directly results from their leaf-heavy diet and their need to conserve energy.
The Chachagua Rainforest provides a prime habitat for howler monkeys, with various fruits and foliage options to keep them nourished. Crucially, these monkeys contribute to the forest by serving as accidental gardeners, dropping seeds as they travel, and helping to reseed the forest floor.
Unfortunately, clear-cutting and logging in some parts of Central America has threatened these essential primates, leaving forests fragmented and forcing them to relocate to less suitable areas.
Without howlers aiding seed dispersal, parts of the rainforest may struggle to regrow, creating a ripple effect across the entire ecosystem. This is why it is so important to take care of the rainforest, and the reserves that protect them.
When you explore the Chachagua Rainforest, whether on our complimentary guided nature walk or while enjoying the natural hot springs, keep your ears open for the iconic roar of the howler monkey.
Spotting one in the canopy can be a magical experience, connecting you to Costa Rica’s vibrant biodiversity. And you can rest assured that every moment of your stay with us, you’re supporting conservation efforts and sustainable practices.
It can feel incredible for your adventurous vacation to also help protect these vocal guardians of the treetops, ensuring they continue to fill the Chachagua Rainforest with their unrivaled calls for generations to come