Cardellina is a genus of passerine birds in the New World warbler family Parulidae. The genus name Cardellina is a diminutive of the Italian dialect word Cardella for the European goldfinch.
Taxonomy
Red warbler
The genus was introduced by the French naturalist Charles Lucien Bonaparte in 1850. The type species was fixed in 1865 by the American naturalist Spencer Baird as Muscicapa rubrifrons Giraud, 1841, the red-faced warbler. The genus originally contained one species, the red-faced warbler. A comprehensive study of the wood-warblers published in 2010 that analysed mitochondrial and nuclear DNA sequences found that the five species formed a discrete clade, with the Wilson's and Canada warblers as early offshoots, followed by a lineage that gave rise to two branches – one leading to the red-faced and another that diverged to the red and pink-headed warblers.
Spencer Fullerton Baird described the genus Ergaticus in 1865, using it to separate several species from what he felt was the closely related genus Cardellina, and eventually subsumed into Cardellina in 2011. Prior to the creation and widespread acceptance of this genus, the red warbler and pink-headed warbler were placed in various other warbler genera, including Setophaga (with the American redstart), Cardellina (with the red-faced warbler), and Basileuterus (a widespread genus of tropical warblers) — as well as the Old World warbler genus Sylvia and the Old World tit genus Parus. Recent DNA analysis shows that Ergaticus falls comfortably within the New World warbler clade, along with 18 other genera. It is closest to the genus Cardellina, with which it shares a common ancestor, and slightly more distantly related to the genus Wilsonia.
There are two sister species, separated by the low-lying Isthmus of Tehuantepec, in the genus. The red warbler, C. ruber, is found in the Mexican highlands north of the isthmus. Its three subspecies, which differ slightly in appearance, are found in three...
