Golden Mantled Howlers at Dawn

Recorded in December 2023 on my first — but not last — trip through Costa Rica, a troop of Golden Mantled Howler Monkeys in Costa Rica’s Parque Nacional Corcovado greets the dawn and their neighbors (and the rest of the jungle) the only way they know how. Male mantled howlers have an enlarged hyoid bone, a hollow amplifying bone near their vocal cords that gives the ability to generate great “howling” calls that can heard for kilometers. Howling allows the monkeys to exercise territory and remain in contact without expending energy through movement or bearing the risks of physical confrontation. As someone who likes little more than sitting in a forest listening to nature speak, I approve of this lazing behavior.

While this howling is their most well-known vocal characteristic, I’m rather fond of the popping and grunting that warms up to the howl and pads the time in between. It’s relatively quiet, and is most noticeable only when near the vocalizing howler. You can hear it throughout their first round of howling the beginning.

After speaking with other recordists, I know I am far from alone as someone who loves their sound, but I may be one of the few that enjoys waking up to their calls. Every morning I heard this nearby was a morning I walked to breakfast with a big silly grin on my face.

Neotropic birds come and go throughout the recording, but one persistent voice was the Yellow-throated Toucan, with a rhythmic, bouncing song that seems to carry on forever. There is at least one singing for most of this recording, and later, after the this first hour, a pair begin a duet. Also coming and going are raucous and noisy Scarlet Macaws and Red-lored Parrots, a lone Red-eyed Tree Frog, a visiting Little Tinamou, and more. I’m out of my depth when it comes to identifying neotropical birds, so I’ll let rest of the ecosystem speak for itself.