Timberline Wren

The Timberline Wren, a diminutive avian species, measures a mere 10 cm in length and tips the scales at 14 grams. This bird is adorned with a rich chestnut brown crown and upperparts, while its tail boasts a reddish hue interspersed with slender dark bars. A striking gray-white supercilium contrasts with a chocolate brown postocular stripe and grayish cheeks marked with fine black lines. The underparts present a grayish white throat and chest, transitioning to a mottled grayish white on the upper belly, with the lower belly taking on a brown shade, and the flanks and vent area a reddish brown. Juveniles display a grayer underside with a scalloped pattern.

Identification Tips

To identify the Timberline Wren, look for its broad gray-white supercilium and the chocolate brown stripe behind the eye. The reddish brown tail with dark bars is also distinctive. Subspecies T. b. ridgwayi is larger with deeper reddish brown upperparts, while T. b. basultoi features a wider supercilium, whitish neck and upperpart markings, and whiter underparts.

Habitat

This wren favors the páramo and near-páramo moorland at the upper reaches of the tree line, showing a particular affinity for bamboo thickets.

Distribution

The Timberline Wren's range is disjunct, spanning from central Costa Rica to northern Panama. It is found at elevations mostly between 2,800 and 3,600 meters, though sightings have been recorded as low as 2,200 meters.

Behaviour

The Timberline Wren is a ground forager, occasionally fluttering to glean prey from foliage or creeping along moss-covered branches.

Song & calls

The song of the Timberline Wren is a unique composition, a series of scratchy, warbling notes repeated over 2-3 seconds. Its call is a harsh 'churr', quite distinct from other wrens.

Breeding

Breeding season in Costa Rica occurs from April to June. The nest is a bamboo leaf ball with a side entrance, placed 1 to 3 meters up in bamboo or a shrub. Clutches typically contain two eggs.

Conservation status

The IUCN has classified the Timberline Wren as Least Concern. Despite its restricted range, it is common to abundant within its preferred habitat, much of which lies within protected national parks.