Torrent Tyrannulet

The torrent tyrannulet, Serpophaga cinerea, is a diminutive member of the tyrant flycatcher family. This sprightly bird measures a mere 10 to 11.4 centimeters in length and tips the scales at approximately 8 grams. The male is distinguished by its pale grey upperparts and a greyish white underbelly, transitioning to pure white at the throat and lower belly. A striking feature is the black cap above the eye level, which conceals a secret white crown patch, while the wings and tail exhibit a blackish hue adorned with two slender grey-white wing bars. The female mirrors the male in plumage, albeit with a greyer head and a smaller or sometimes absent crown patch. Juveniles can be recognized by their browner cap, a brownish wash over the upperparts, and broader, more yellowish wing bars.

Identification Tips

When attempting to identify the torrent tyrannulet, look for its pale grey and white plumage, the concealed white crown patch on the males, and the characteristic wing bars. The bird's small size and agile movements are also key identification features.

Habitat

The torrent tyrannulet is an inhabitant of rocky mountain streams, thriving at elevations ranging from 300 to 2200 meters. It is less frequently encountered at lower altitudes where the water currents are gentler. Notably, there has been a nesting record in Costa Rica at an elevation as low as 35 meters, potentially due to displacement by hydroelectric projects along the Sarapiquí River.

Behaviour

This species constructs a substantial cup nest on a branch, sometimes reaching up to 4 meters above water, or on a rocky shore. The nest is meticulously lined with feathers and camouflaged with moss on the exterior. The clutch typically consists of two unmarked pale buff or whitish eggs. The torrent tyrannulet is an insectivore, adept at capturing its prey mid-flight or plucking it from vegetation or rocks along the bankside. Its flight is reminiscent of a dipper, swift and low over the water. A notable behavior is the frequent tail pumping while perched on a streamside rock.

Song & Calls

The vocalizations of the torrent tyrannulet are well-suited to its aquatic environment. Its call is a sharp, penetrating "chip," which can be heard over the sound of rushing water. The song is a more leisurely sequence of the call or a "seek" followed by a trilled "ti,ti,ti,ti,ti,ti."

Conservation status

The IUCN Red List has classified the torrent tyrannulet as Least Concern, indicating that, at present, there are no immediate threats to its population numbers that would warrant a higher level of concern.