Ruddy Treerunner

How to find it

Check mixed flocks of bush tanagers in highland forest, and look for the treerunner working through moss and epiphyte clumps on branches. Guides on Costa Rica tours have found it by watching mixed flocks in highland oak forest in the Savegre Valley and in cloud forest at Santa Elena. Look for it in canopy flocks that move along trails. A flock may carry it past while other birds linger, so be ready to follow the flock.

How to recognise it

This is a small bird, about 16 cm and 18 g.

Look for these marks:

- bright rufous upperparts

- a white eyebrow stripe

- a white throat

- tawny underparts, with fine pale spots edged in black on the breast

- a flesh colored bill with a dusky base on the upper ridge

Young birds look almost the same as adults, so there are no age plumages to puzzle over. Across its range it looks like a small woodcreeper with a short bill, and its tail ends in soft spines rather than stiff ones.

Behaviour and diet

The Ruddy Treerunner specialises in foraging among epiphytes. It pokes its bill into moss, lichen and dead leaves caught in vines, hunting small insects and spiders, plus their eggs and larvae.

Birds are found alone or in pairs. They often join mixed flocks that include Chlorospingus (bush tanagers).

Where it lives

In Costa Rica this treerunner is a common resident of high mountains. It starts at about 1200 m in the Guanacaste range, 1500 m in Tilarán, and 1850 m in the Central Volcanic and Talamanca ranges, and it reaches the upper forest limit. It ranges lower on the Caribbean slope than on the Pacific slope.

It uses all levels of montane forest up to the mid canopy. It also visits forest margins, scrub, and clearings with scattered trees.

When to see it

Newly fledged young have been seen between May and July at Villa Mills on Cerro de la Muerte. The breeding season is not fully defined across its range, but seems to run from March to May.

Similar birds

At a glance it can be taken for a small woodcreeper, since it climbs in a similar way. The short bill, the white eyebrow stripe and the white throat help set it apart, as do the soft-spined tail tips.

Names and lore in Costa Rica

Besides the AOCR name Subepalo Rojizo, Costa Rican bird lists use the nickname Chupamusgo. One reserve list also gives Trepamusgo Rojizo, and another Spanish name for the species is pijuí rojizo.

Status and conservation

The AOCR lists it as a resident endemic (R-END), and it is rated Least Concern with a stable population.

Photography tips

Watch for canopy flocks moving through the forest along trails, and be ready to follow the flock as it passes, since the treerunner may move on while other birds linger.