Northern Nightingale-Wren

The Northern Nightingale-Wren, scientifically known as Microcerculus philomela, is a diminutive passerine bird belonging to the family Troglodytidae. This species exhibits a predominantly dark brown plumage, with a dark gray throat and breast. The feathers are tipped with black, imparting a scalloped appearance to both the upper and underparts. Adult birds typically measure between 10 to 11.5 cm in length, with males weighing between 17.4 to 21.5 grams and females slightly lighter at 16.4 to 17.4 grams. Juveniles resemble adults but feature darker scaling on their upperparts and whitish to pale gray scaling on the underparts.

Identification Tips

When attempting to identify the Northern Nightingale-Wren, look for its small size and dark brown coloration. The scalloped feather pattern is distinctive, as is the contrast between the dark gray throat and breast and the darker body. This bird is often seen foraging close to the ground, which can also aid in identification.

Habitat

The Northern Nightingale-Wren is a denizen of the lowland tropical forests, with a strong preference for the interior of virgin evergreen and undisturbed cloud forests. It thrives in the dense undergrowth where it can easily remain concealed.

Distribution

This species is distributed from Chiapas in Mexico, extending through Guatemala, southern Belize, Honduras, Nicaragua, and into northern Costa Rica. It is predominantly found along the Atlantic side but also occurs locally on the Pacific side in Chiapas and Costa Rica. Its elevation range varies from sea level in Mexico up to 1,400 meters, and in Costa Rica, it is more commonly found up to 1,200 meters.

Behaviour

The Northern Nightingale-Wren is a ground-dweller, often seen foraging in undergrowth, brush piles, and on fallen logs. It is known to opportunistically follow army ant swarms, taking advantage of the insects they disturb.

Song & calls

The vocal repertoire of this bird includes a series of confident to hesitant, rising and falling whistles. Its song is often delivered from low perches and can be heard throughout most of the year.

Breeding

Breeding activity for the Northern Nightingale-Wren has been observed from May to September in Costa Rica. However, details on its nesting biology remain largely unknown.

Diet and Feeding

The diet of the Northern Nightingale-Wren is almost exclusively composed of insects, which it actively searches for on the forest floor and in the undergrowth.

Conservation status

The IUCN has classified the Northern Nightingale-Wren as Least Concern. Despite this, the species faces threats in much of its range due to habitat loss from deforestation and land clearing for agriculture, which impacts its preferred undisturbed forest habitats.