Oporornis is a small genus of New World warblers which breed in North America. They are migratory, wintering south of their breeding ranges in Central or South America.

The four species are:

• Kentucky Warbler, Oporornis formosus
• Connecticut Warbler, Oporornis agilis
• Mourning Warbler, Oporornis philadelphia
• MacGillivray's Warbler, Oporornis tolmiei

Oporornis warblers are robust stocky birds, 13–15 cm long. They have yellow underparts, olive green upperparts and generally browner wings. The head and breast are grey in the males of three species, with the females’ hood being browner and duller. However, the Kentucky Warbler looks more like a yellowthroat, with the entire underparts yellow, and black head markings in the male plumage. This species may be a link between Oporornis warblers and the yellowthroats.

The breeding habitat is broadleaved woodlands, often in wet areas and with dense undergrowth. These skulking, fairly terrestrial warblers nest low in a bush or on the ground, laying 3-6 eggs in a cup nest.

Oporornis warblers feed on insects and spiders often caught on the ground or low in vegetation; they have simple churring songs and buzzing calls.

Taxonomy

Recent genetic research has suggested that only the type species of Oporornis (Connecticut Warbler O. agilis, which is also the most distinctive member of the genus) should be retained in Oporornis, with the other three more closely related to, and better placed in, the genus Geothlypis.^[1] This change has been accepted by the AOU,^[2] but has not yet been taken up by the IOC.^[3]

References

• New World Warblers by Curson, Quinn and Beadle, ISBN 0-7136-3932-6