Hepatic Tanager is the most widely distributed Piranga tanager, ranging from the southwest United States south to northern Argentina. Its English name is based on the liver-red color of the adult male from the northern part of the species' range; however, its scientific name, flava, meaning “yellow,” derives from the original description, which is based on a female from Paraguay. These names reflect both a characteristic of the genus Piranga, marked sexual dichromatism, and the broad range of coloration, habitat, and behavior encompassed within the Hepatic Tanager as currently recognized.
In the United States through Central America, Hepatic Tanager breeds mostly in open pine (Pinus) or pine-oak (Quercus) forests and similar habitats at moderately high altitudes, moving to lower elevation in winter. Northern populations are migratory, but a few individuals often remain in northern breeding areas during winter. The species migrates in small flocks and may follow river valleys; banding data that might indicate the magnitude of migratory movements and migration routes are nonexistent.
Even though the Hepatic Tanager is currently considered one species, much evidence, including a recent study of molecular genetics, indicates that up to 3 species could be recognized, corresponding to the 3 groups of subspecies combined long ago. These groups and their respective species names are the Hepatic Tanager (P. hepatica) of montane pine-oak forests from the southwestern United States to Nicaragua, the Tooth-billed Tanager (P. lutea) of forest edges in foothills and mountains from Costa Rica to northern and western South America, and the Red Tanager (P. flava) of open woodlands of eastern and southeastern South America. These group names are used throughout this account, the primary focus of which is on the northern hepatica group.
Even though this species is relatively common in some areas of Arizona and New Mexico, little is known about many aspects of its biology—notably reproduction, diet, and population biology. Such basic information as quantitative habitat information, vocal repertoire, incubation period, renesting, and a description of the natal down is lacking, so this species offers much potential for a study of life history. Information on very basic natural history and geographic variation is available (Zimmer 1929). The Hepatic Tanager is also included in studies of tanagers in the genus Piranga, including song (Shy 1984b), habitat and geographic variation (Shy 1984a), systematics (Burns 1998), and plumage coloration (Brush 1967b, Hudon 1990b).
The Hepatic Tanager appears to have relatively stable to expanding populations, probably because of the secure nature of much of its breeding habitat in the United States. Qualitative information suggests it has expanded its range in the United States considerably in recent decades, although the cause of this expansion is not known. Much more needs to be learned about this species before conservation strategies can be developed for it.