White-throated Treerunner

The White-throated Treerunner, Pygarrhichas albogularis, is a distinctive bird of the Furnariidae family, the sole representative of its genus. This bird, approximately 15 cm in length, is characterized by its stiff, rounded tail and a striking contrast between its dark brown upperparts, which turn red on the lower back and tail, and the bright white of its throat and chest. The bill is notably long and slightly curved upwards, and the bird's general appearance is reminiscent of a nuthatch, though they are not closely related.

Identification Tips

To identify the White-throated Treerunner, look for its white throat and chest, which sharply contrast with the dark brown upperparts. The lower back and tail exhibit a reddish hue. The bird's bill is long and slightly upcurved, and its tail is stiff and rounded, aiding in its arboreal maneuvers.

Habitat

This species is found in forests with large trees, which provide nesting sites in old trunks. It inhabits both lowland and highland forests, dense or open, from sea level to 1,200 meters in altitude.

Distribution

The White-throated Treerunner is native to the southern tip of the American continent, residing in Chile and Argentina, from Santiago and Mendoza to Tierra del Fuego.

Behaviour

The White-throated Treerunner is known for tirelessly scouring the trunks and branches of old trees for small arthropods, spiraling up the trunks or sometimes moving head down. Outside of the breeding season, it may form mixed-species foraging flocks with other bird species.

Song & Calls

The bird's vocalizations include a short, piercing cry reminiscent of a rapid succession of water droplets. Its contact call is a loud, fast, metallic "kik-ik" or "tsi-ik," repeated rapidly. It also emits a sonorous "peet peet" and a dry "tic" during flight.

Breeding

Nesting occurs in tree cavities, often in senescent or fire-damaged trees. The White-throated Treerunner is thought to be monogamous, laying two to three eggs per breeding season, which spans the southern spring and summer.

Similar Species

While the White-throated Treerunner bears a resemblance to nuthatches and other tree-bark gleaning Furnariidae, these similarities are the result of convergent evolution rather than direct relatedness.

Diet and Feeding

The diet consists primarily of small invertebrates found on bark. The bird forages on trees such as Coigüe, Neuquén Roble, and Ulmo, often preferring dead trees due to the abundance of accessible insects.

Conservation status

The White-throated Treerunner is classified as "Least Concern" by the International Union for Conservation of Nature (IUCN), with a stable population and a relatively large range. However, the species relies on old senescent trees for nesting, a habitat that is specific and scarce, warranting conservation efforts.