High in the lush embrace of the Costa Rican rainforest, a symphony of birdsong fills the air. But amidst the chorus, some performers are harder to spot than others. Today, we turn our gaze to a tiny titan of the treetops, the Yellow-bellied Tyrannulet.

This miniature maestro belongs to the vast family of Tyrannidae, more commonly known as flycatchers. True to their name, tyrannulets are insectivores extraordinaire, flitting amongst the leaves and scooping up unsuspecting bugs. But the Yellow-bellied Tyrannulet stands out for its diminutive size – a mere 10.5 cm long and weighing a featherlight 8 grams!

Despite its stature, the Yellow-bellied Tyrannulet is a marvel of color. Its upperparts are adorned with a beautiful olive-green, a perfect camouflage against the verdant foliage. But peek underneath, and a vibrant surprise awaits. The bird’s belly bursts with a sunshine yellow, a beacon that sets it apart from the surrounding greenery.

Adding to its charm is a crisp white or pale yellow eyebrow, a striking feature that frames its dark eyes. The wings and tail are a dusky brown, subtly edged with yellow, and boast two faint yellowish wingbars. Interestingly, the plumage shows slight variations across its range, with some individuals sporting a browner back or a slightly different shade of yellow.

While the Yellow-bellied Tyrannulet might be tiny, its voice packs a punch. Its call is a soft but distinct “pewik,” a sound that’s easy to miss amongst the rainforest’s cacophony. But listen closely, and you might be rewarded with their melodious duet song, a rhythmic “pee-tic-keek” that adds to the enchanting soundscape.

Spotting a Yellow-bellied Tyrannulet can be a challenge. These little insectivores primarily inhabit the dense upper canopy of humid tropical forests, flitting amongst leaves and clinging to branches with their tiny feet. Their preference for the higher reaches makes them easily overlooked by casual observers.

However, here at our Costa Rican retreat, nestled amidst the mountains, you have a fantastic chance of encountering these shy songbirds. With a little patience and a keen eye, you might catch a glimpse of them as they forage for insects at the forest’s edge or descend lower in search of prey.

Tips for Spotting a Yellow-bellied Tyrannulet:

• Early mornings are prime birding time: As the forest awakens, the Yellow-bellied Tyrannulet becomes more active, making it easier to spot.
• Focus on the sounds: Their calls and songs can be your best indicators of their presence.
• Look for movement in the upper canopy: A flash of yellow or a tiny bird flitting amongst the leaves might be your lucky break.
• Join a guided birdwatching tour: Our experienced guides know the forest intimately and can help you spot these elusive birds.

The Yellow-bellied Tyrannulet might be small, but it plays a vital role in the rainforest ecosystem. By preying on insects, they help control their populations and maintain a healthy balance. So, the next time you’re exploring the Costa Rican mountains, keep an ear out for their calls and an eye out for a flash of yellow in the canopy. You might just be lucky enough to meet this delightful little denizen of the trees.

For more information, please view our comprehensive guide about the birds of Costa Rica

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