Least Flycatcher

How to find it

Work forest edges, old second growth and scrubby regrowth rather than deep forest. Cacao and other tree plantations are worth a slow walk too. Scan at shrub height and in the upper understory, and look up for quick movements and frequent changes of perch. Because winter birds are solitary and stay in one spot, a place where you find one may be worth rechecking. Confirm the small size and the bold white eye ring, since on migration it may be silent and hard to tell apart.

How to recognise it

Start with size: about 11.5 cm long, the smallest and greyest of the migrant Empidonax in Costa Rica.

Look for these marks:

A small bill, short and broad, with a pale lower half.

A notched tail.

A notably bright white eye ring and wing bars.

Grey olive upperparts, with a grey crown and nape that show little or no green tint.

A white throat and a dull olive wash on the breast.

A yellow tint on the belly and flanks.

Its short wing tips let it pump its tail upward without flicking its wings.

What it sounds like

Recording: Sean Vanderluit, CC BY 4.0, source, read 4 Nov 2026.

Behaviour and diet

In winter in Costa Rica the Least Flycatcher is solitary and stays in one spot, and it may defend a territory. It hunts by short sallies and hovering flights within the vegetation, like other migrant Empidonax. It catches insects from branches in the middle to upper levels and changes perches often, so quick movements are the clue to look for. Empidonax flycatchers in general often flick their wings and tails quickly.

Where it lives

In Costa Rica it lives at forest edges, old second growth, scrubby regrowth and tree plantations such as cacao. It usually stays low, at shrub height and in the upper understory.

It is mostly a lowland bird on both the Caribbean and Pacific slopes. On migration it climbs to at least 1200 m in the central highlands.

When to see it

It arrives from early October and stays until at least late April.

Similar birds

Costa Rica's other Empidonax species include Alder, Willow, White-throated, Yellowish and Black-capped flycatchers. The group is often confusing, but the Least is one of the easier ones to identify. Small size, a grey crown and nape and a bold eye ring help set it apart.

Names and lore in Costa Rica

In Costa Rica the bird is called mosquerito chebec. Other Spanish speaking countries use different names, such as mosquerito menor in Honduras and mosquerito mínimo in Mexico. The English name 'chebec' is an old nickname that imitates the sound of its song.

Status and conservation

On the AOCR list it is a migrant (M), a winter resident that is very rare in the lowlands of both slopes, and its population trend is listed as decreasing.

Photography tips

Look up for quick movements and frequent changes of perch, at shrub height and in the upper understory. A bird that holds one spot in winter can be returned to for a better look.