Black-and-white Warbler

How to find it

Start by listening: the song is thin and squeaky but carries well, so it is a good way to locate the bird. Then scan trunks and limbs rather than leaves, looking for a striped bird creeping along the bark. Check mixed flocks, since it turns up with them in many kinds of forested places. Gardens are worth your time too, as one birder logged the first fall bird during a garden and riparian morning. Look for the fanning tail as a quick confirmation.

How to recognise it

Look for a small bird, about 13 cm long, with sharp black and white stripes on the head, back and flanks.

Two white wing bars cross the wing. Males have a black throat and cheeks, while females have white ones, which is the easiest way to tell the sexes apart.

Its way of moving is as useful as its pattern. It is the only North American wood-warbler that regularly feeds on bark, and it forages mostly at mid-height, though anywhere from canopy to forest floor. Its slightly downcurved bill probes the bark for insects. One Costa Rica birder noted that both sexes constantly fan the tail, which makes them easy to pick out.

What it sounds like

Recording: Sam E, CC BY 4.0, source, read 4 Nov 2026.

Behaviour and diet

It climbs along tree branches in a slow, deliberate way, unlike most other warblers. That clambering style is the best clue when the bird is partly hidden in foliage.

It is often busy foraging along tree limbs and is not shy. It often joins mixed feeding flocks that include resident tropical birds and other migrants, while still defending its own territory.

It feeds mostly by probing bark for insects but also picks food from foliage like other warblers.

Where it lives

On its wintering grounds it uses forest edge, disturbed areas, plantations, parks and gardens, but is most abundant in interior forest. In winter it also uses mangroves, dwarf forest, humid to semi-arid forest, coffee plantations, regrowth woodland and gardens.

In Costa Rica it has been seen in gardens on the slopes of Turrialba Volcano through the northern winter, in the forest around Caño Negro in the far north, and on the Pacific slope, where a local writer calls it a common bird, reported up to about 2,550 m.

When to see it

A Costa Rica birder has seen it from very late August to the second week of April, and a Pacific slope writer calls it a common visitor from July to May. Birding from late October to early March should turn up winter warblers, including this species.

Similar birds

Few other birds share its stripes and its habit of creeping along bark. Its clambering style along branches is unlike most other warblers, so behaviour is a better clue than colour alone. Watch for the two white wing bars and the striped head.

Names and lore in Costa Rica

The AOCR name, and the Costa Rican name, is Reinita Trepadora (Zebrita). Spanish speakers elsewhere also say cebrita, chipe trepador, pegapalo or reinita rayada. The genus name Mniotilta comes from Greek words meaning moss and to pluck, and varia is Latin for variegated or varied.

Status and conservation

Listed as M on the AOCR list, a migrant that breeds in the eastern and central United States and much of Canada and winters across Mexico, Central America, the Caribbean and northern South America.

Photography tips

The constant tail fanning in both sexes makes the bird easy to pick out, and its clambering style along branches sets it apart from most other warblers. Watch the trunks and limbs, and let the thin song lead you to it.