Chestnut-sided Shrike Vireo, Vireolanius melitophrys

Chestnut-sided Shrike Vireo, Vireolanius melitophrys. Photograph taken in Temascaltepec, Mexico, March 2018. Photograph and identification courtesy of David F Smith, Alamos.

Background and Identification

The Chestnut-sided Shrike Vireo, Vireolanius melitophrys, is a member of the Vireonidae family of Vireos, Shrike-Babblers, and Erpornis. This is a striking bird characterized by its distinct facial and chest coloring and robust build. A sedentary bird, no known migration patterns exist. In Mexico, this species is known as Vireón Pechicastaño.

Measuring approximately 15 cm (5.9 inches) in length, this bird is known for its vibrant green back, yellowish underparts, and prominent chestnut-colored stripe running along its flanks, giving the species its name. The head is adorned with a broad black stripe through the eye, bordered by white above and below, creating a masked appearance. Females and males have similar plumage patterns and size (monomorphic), but female supercilium and chestband are duller.  Its stout, hooked bill is another distinguishing feature, which reflects its diet. Diet includes a mix of insects and small fruits. The bird’s song is a series of clear, whistled notes, often heard high in the forest canopy.

Habitat and Geographical Range

The Chestnut-sided Shrike Vireo is typically found in montane forests, particularly in the mid-to-upper canopy levels. It prefers mixed pine-oak forests and cloud forests at elevations ranging from 1,200 m (3,900 feet) to 3,000 m (9,800 feet).

This species is primarily distributed in Mexico (almost considered an endemic species), from the Sierra Madre Oriental and Sierra Madre del Sur to the central highlands, extending into narrow parts of Guatemala. It is often seen foraging in mixed-species flocks, moving methodically through the trees in search of insects and other prey.

Common Misidentifications

The Chestnut-sided Shrike Vireo might be confused with other shrike vireos or large vireos that share its range. However, its distinctive chestnut sides and bold facial markings usually set it apart. One species it might be mistaken for is the Green Shrike Vireo, Vireolanius pulchellus, but the latter lacks the chestnut sides and has a more uniformly green appearance.

Conservation Status

From a conservation perspective the Chestnut-sided Shrike Vireo is currently considered to be of Least Concern with stable widely distributed populations. While they occupy a relatively specialized habitat, its population appears to be stable across its entire geographical range. Ongoing deforestation in Mexico’s montane areas poses a large threat, and conservation efforts that focus on preserving these forest habitats are essential for the continued survival of this species.