The white-winged warbler is a small but robust bird, with a long tail and strong beak, making it a bit of an oddity when compared with the true warblers (family Parulidae). Its upperparts are olive green, and the wings blackish, showing a white patch when closed and lending this bird its name in English – and identically in Spanish – ciguita aliblanca. Like the wing, its underparts are white, while the head, nape, and flanks are gray. The white eye ring is broken in front and back, forming a crescent above and below each eye. It has a small black mark between the bill and eye, and a white line above the black mark. Its plumage recalls a miniature black-crowned palm-tanager, which is exactly what some locals call it in the Dominican Republic and Haiti. The White-winged Warbler’s size and appearance suggest it is a warbler (family Parulidae), where, indeed, it was initially placed. However, genetic studies indicate a closer affinity with the tanager family (Thraupidae), its closest relatives being the black-crowned palm-tanager and sister species, and the green-tailed warbler (Microligea palustris).
In contrast to other sister species pairs, the distribution of white-winged and green-tailed warblers, overlaps in south-central Hispaniola, and thus does not suggest separate evolution on each of the two paleo-islands of Hispaniola. This presents a mystery for scientists, since the evolution of closely related species on the same island is unknown on islands the size of Hispaniola. It is thought that it would take at least ten times greater area for this type of sympatric evolution, (sympatric meaning “same place”) to occur. For now, we know through genetic studies only that these tanagers evolved from an ancient songbird ancestor, possibly before all other Hispaniolan endemic birds, when Hispaniola, as we know it today did not yet exist.
As its scientific name implies, the white-winged warbler is a high mountain bird, mainly found in broadleaf forests, where it feeds on insects and seeds. It forages from the ground up to the highest branches, often in pairs, or in flocks with other species. One of its favorite foods is the fruit of the Florida Trema (Trema micrantha). Like the green-tailed warbler, it is usually very quiet. Its voice is a low chattering suit . . suit . . suit . . chirr . . suit . . suit . . suit . . . chirr . . chi. Also a thin tseep. Although it rarely sings, its song is a series of high-pitched, squeaky notes, often accelerating at the end. Despite being first described in 1917, this bird remains enigmatic. Its nest – a small cup constructed of moss, leaves and plant fibers – was not discovered until nine decades later, in 2004.
“Both delight in the thick brush and fern thickets found in high La Selle, where they creep about noiselessly.” James Bond, describing Microligea palustris and Xenoligea montana
“Doña, it seems to me that you are looking for the small black-crowned tanager.” Expression of a villager recorded by Anabelle Stockton de Dod
“What a beautiful bird! Again, I was thinking of a small black-crowned tanager.” Anabelle Stockton de Dod
The only egg ever observed was pale green with faint reddish-brown spots. Some experts consider the Whitewinged Warbler to be one of the most endangered endemic birds of Hispaniola.220 The IUCN Red List classifies it as vulnerable to extinction, due to its highly restricted distribution which is severely fragmented by the extensive loss of the montane forests on which it depends. The high degree of threat may be better reflected in the Dominican Republic’s Red List, which classifies it as endangered.