The New World warblers or wood-warblers are a group of small, often colorful, passerine birds that make up the family Parulidae and are restricted to the New World. The family contains 120 species. They are not closely related to Old World warblers or Australian warblers. Most are arboreal, but some, like the ovenbird and the two waterthrushes, are primarily terrestrial. Most members of this family are insectivores.

This group likely originated in northern Central America, where the greatest number of species and diversity between them is found. From there, they spread north during the interglacial periods, mainly as migrants, returning to the ancestral region in winter. Two genera, Myioborus and Basileuterus, seem to have colonized South America early, perhaps before the two continents were linked, and together constitute most warbler species of that region.

The scientific name for the family, Parulidae, originates from the fact that Linnaeus in 1758 named the northern parula as a tit, Parus americanus, and as taxonomy developed, the genus name was modified first to Parulus and then to Parula. The family name derives from the name for the genus.

Taxonomy

The family Parulidae was introduced for the New World warblers in 1947 by American ornithologist Alexander Wetmore and collaborators with Parula as the type genus. Parula is now considered as a junior synonym of Setophaga.

The family was formerly thought to be sister to a clade containing the yellow-breasted chat in its own family Icteriidae, the wrenthrush in its own family Zeledoniidae, the two Cuban warblers in the family Teretistridae and the 109 species in the family Icteridae. However, more recent studies recover them as sister to a clade containing just the yellow-breasted chat and the Icteridae, with the clade containing all three families being sister to a clade containing the chat-tanagers in Calyptophilidae, the wrenthrush, and the Phaenicophilidae.

A molecular phylogenetic study of the Parulidae published in 2010 found that the species formed several major clades that did not align with the traditional genera. This led to a major reorganization of the species within the family to create monophyletic genera. The changes have generally followed the recommendations of the authors of the study except in a few cases where the proposed genera were split.

A large clade that included the 29 species then placed in the genus Dendroica, also included four species of Parula, one of the three species of Wilsonia and the monotypic genera Catharopeza and Setophaga. All members of the clade apart from Catharopeza were placed in the expanded genus Setophaga Swainson, 1827, which under the rules of the International Code of Zoological Nomenclature, had priority over Dendroica Gray, 1842, Wilsonia Bonaparte, 1838, and Parula Bonaparte, 1838.

The species that had traditionally been placed in Basileuterus formed two clades. One group retains the genus name as it includes the golden-crowned warbler, the type species for the genus. The other larger group, now with 18 species, is placed in the resurrected genus Myiothlypis Cabanis, 1850, as it contains the type species, the black-crested warbler.

The genus Myioborus containing the whitestarts remained unchanged after the reorganization but six genera were no longer used: Dendroica, Ergaticus, Euthlypis, Parula, Wilsonia and Phaeothlypis.

Extant Genera The family Parulidae now contains 120 species divided into 18 genera. Image Genus Living speciesSeiurus Ovenbird, Seiurus aurocapillaHelmitheros Worm-eating warbler, Helmitheros vermivorumParkesia Northern waterthrush, Parkesia noveboracensis Louisiana waterthrush, Parkesia motacillaVermivora Bachman's warbler, †Vermivora bachmanii (Extinct: Between 1988 and 2023) Blue-winged warbler, Vermivora cyanoptera Golden-winged warbler, Vermivora chrysopteraMniotilta Black-and-white warbler, Mniotilta variaProtonotaria Prothonotary warbler, Protonotaria citreaLimnothlypis Swainson's warbler, Limnothlypis swainsoniiOreothlypis Flame-throated warbler, Oreothlypis gutturalis Crescent-chested warbler, Oreothlypis superciliosaLeiothlypis Tennessee warbler, Leiothlypis peregrina Orange-crowned warbler, Leiothlypis celata Colima warbler, Leiothlypis crissalis Lucy's warbler, Leiothlypis luciae Nashville warbler, Leiothlypis ruficapilla Virginia's warbler, Leiothlypis virginiaeLeucopeza Semper's warbler, Leucopeza semperiOporornis Connecticut warbler, Oporornis agilisGeothlypis Common yellowthroat, Geothlypis trichas Belding's yellowthroat, Geothlypis beldingi Altamira yellowthroat, Geothlypis flavovelata Bahama yellowthroat, Geothlypis rostrata New Providence yellowthroat, †Geothlypis rostrata rostrata (extinct: 1990s?) Olive-crowned yellowthroat, Geothlypis semiflava Black-polled yellowthroat, Geothlypis speciosa Masked yellowthroat, Geothlypis aequinoctialis Southern yellowthroat, Geothlypis velata Black-lored yellowthroat, Geothlypis auricularis Chiriqui yellowthroat, Geothlypis chiriquensis Gray-crowned yellowthroat, Geothlypis poliocephala Hooded yellowthroat, Geothlypis nelsoni MacGillivray's warbler, Geothlypis tolmiei Mourning warbler, Geothlypis philadelphia Kentucky warbler, Geothlypis formosaCatharopeza Whistling warbler, Catharopeza bishopiSetophaga Plumbeous warbler, Setophaga plumbea Elfin woods warbler, Setophaga angelae Arrowhead warbler, Setophaga pharetra Hooded warbler, Setophaga citrina American redstart. Setophaga ruticilla Kirtland's warbler, Setophaga kirtlandii Cape May warbler, Setophaga tigrina Cerulean warbler, Setophaga cerulea Northern parula, Setophaga americana Tropical parula, Setophaga pitiayumi Magnolia warbler, Setophaga magnolia Bay-breasted warbler, Setophaga castanea Blackburnian warbler, Setophaga fusca American yellow warbler, Setophaga aestiva Mangrove warbler, Setophaga petechia Chestnut-sided warbler, Setophaga pensylvanica Blackpoll warbler, Setophaga striata Black-throated blue warbler, Setophaga caerulescens Palm warbler, Setophaga palmarum Olive-capped warbler, Setophaga pityophila Pine warbler, Setophaga pinus Myrtle warbler, Setophaga coronata Audubon's warbler, Setophaga auduboni Black-fronted warbler, Setophaga auduboni nigrifrons Goldman's warbler, Setophaga goldmani Yellow-throated warbler, Setophaga dominica Bahama warbler, Setophaga flavescens Vitelline warbler, Setophaga vitellina Prairie warbler, Setophaga discolor Adelaide's warbler, Setophaga adelaidae Barbuda warbler, Setophaga subita Saint Lucia warbler, Setophaga delicata Grace's warbler, Setophaga graciae Black-throated grey warbler, Setophaga nigrescens Townsend's warbler, Setophaga townsendi Hermit warbler, Setophaga occidentalis Golden-cheeked warbler, Setophaga chrysoparia Black-throated green warbler, Setophaga virens Yellow-rumped warbler, Setophaga coronataMyiothlypis Citrine warbler, Myiothlypis luteoviridis Santa Marta warbler, Myiothlypis basilica White-striped warbler, Myiothlypis leucophrys Flavescent warbler, Myiothlypis flaveola Gray-headed warbler, Myiothlypis griseiceps White-rimmed warbler, Myiothlypis leucoblephara Black-crested warbler, Myiothlypis nigrocristata Pale-legged warbler, Myiothlypis signata Buff-rumped warbler, Myiothlypis fulvicauda Riverbank warbler, Myiothlypis rivularis Two-banded warbler, Myiothlypis bivittata Cuzco warbler, Myiothlypis chrysogaster Choco warbler, Myiothlypis chlorophrys White-lored warbler, Myiothlypis conspicillata Grey-throated warbler, Myiothlypis cinereicollis Grey-and-gold warbler, Myiothlypis fraseri Russet-crowned warbler, Myiothlypis coronataBasileuterus Golden-crowned warbler, Basileuterus culicivorus White-bellied warbler, Basileuterus culicivorus hypoleucus Three-banded warbler, Basileuterus trifasciatus Rufous-capped warbler, Basileuterus rufifrons Chestnut-capped warbler, Basileuterus delattrii Golden-browed warbler, Basileuterus belli Black-cheeked warbler, Basileuterus melanogenys Pirre warbler, Basileuterus ignotus Three-striped warbler, Basileuterus tristriatus Yungas warbler, Basileuterus punctipectus Black-eared warbler, Basileuterus melanotis Tacarcuna warbler, Basileuterus tacarcunae Fan-tailed warbler, Basileuterus lachrymosusCardellina Canada warbler – Cardellina canadensis Wilson's warbler – Cardellina pusilla Red-faced warbler – Cardellina rubrifrons Red warbler – Cardellina rubra Pink-headed warbler – Cardellina versicolorMyioborus Painted whitestart, Myioborus pictus Slate-throated whitestart, Myioborus miniatus Brown-capped whitestart, Myioborus brunniceps Yellow-crowned whitestart, Myioborus flavivertex White-fronted whitestart, Myioborus albifrons Golden-fronted whitestart, Myioborus ornatus Spectacled whitestart, Myioborus melanocephalus Collared whitestart, Myioborus torquatus Paria whitestart, Myioborus pariae White-faced whitestart, Myioborus albifacies Guaiquinima whitestart, Myioborus cardonai Tepui whitestart, Myioborus castaneocapillus

Former species Some species that were previously placed in the Parulidae have been moved to other families:

Olive warbler (Peucedramus taeniatus) – now in own family Peucedramidae Yellow-breasted chat (Icteria virens) – now in own family Icteriidae Three species in the genus Granatellus – now in the family Cardinalidae Red-breasted chat (Granatellus venustus) Grey-throated chat (Granatellus sallaei) Rose-breasted chat (Granatellus pelzelni) Wrenthrush (Zeledonia coronata) – now in own family Zeledoniidae Two species endemic to Hispaniola – now in family Phaenicophilidae Green-tailed warbler (Microligea palustris) White-winged warbler (Xenoligea montana) Two species endemic to Cuba in the genus Teretistris – now in own family Teretistridae Yellow-headed warbler (Teretistris fernandinae) Oriente warbler (Teretistris fornsi)

Description All the warblers are fairly small. The smallest species is Lucy's warbler (Leiothlypis luciae), with a weight of around 6.5 g (0.23 oz) and an average length of . The Parkesia waterthrushes, the ovenbird, the russet-crowned warbler, and Semper's warbler, all of which can exceed and 21 g (0.74 oz), may be considered the largest.

The migratory species tend to lay larger clutches of eggs, typically up to six, since the hazards of their journeys mean that many individuals will have only one chance to breed. In contrast, the laying of two eggs is typical for many tropical species, since the chicks can be provided with better care, and the adults are likely to have further opportunities for reproduction.

Many migratory species, particularly those which breed further north, have distinctive male plumage at least in the breeding season, since males need to reclaim territory and advertise for mates each year. This tendency is particularly marked in the large genus Setophaga (formerly Dendroica). In contrast, resident tropical species, which pair for life, show little if any sexual dimorphism, but exceptions occur. The Parkesia waterthrushes and ovenbird are strongly migratory, but have identical male and female plumage, whereas the mainly tropical and sedentary yellowthroats are dimorphic. The Granatellus chats also show sexual dimorphism, but due to recent genetic work, have been moved into the family Cardinalidae (New World buntings and cardinals).

The name warbler is a misnomer for the New World group of warblers established before the family was split from the Old World warblers in the 1830s. The Random House Dictionary defines "to warble" as "to sing with trills." Most New World warblers do not warble, but rather "lisp, buzz, hiss, chip, rollick, or zip."

References

Further reading Curson, Quinn and Beadle, 1994. New World Warblers. 252 p. 

Harrison, Hal H. 1984. Wood Warblers’ World. New York : Simon and Schuster, 335 p., 24 p. of plates : ill. (some col.); 25 cm.