Systematics

Sylvia agilis Wilson, 1812, American Ornithology: The Natural History of the Birds of the United States, 5:64 (30 Wilson, A. (1812). American Ornithology. Volume 5. Bradsford and Inskeep, Philadelphia, PA, USA. Close ). Type locality given as "Connecticut" (30 Wilson, A. (1812). American Ornithology. Volume 5. Bradsford and Inskeep, Philadelphia, PA, USA. Close ).

None described.

Monotypic.

Oporornis agilis fits squarely within the narrow, monophyletic family Parulidae (New World warblers or wood warblers) identified by Lovette et al. (31 Lovette, I. J., J. L. Perez-Eman, J. P. Sullivan, R. C. Banks, I. Fiorentino, S. Cordoba-Cordoba, M. Echeverry-Galvis, F. K. Barker, K. J. Burns, J. Klicka, S. M. Lanyon, and E. Bermingham (2010). A comprehensive multilocus phylogeny for the wood-warblers and a revised classification of the Parulidae (Aves). Molecular Phylogenetics and Evolution 57:753–770. Close ), whose comprehensive genetic study shook up relationships within the family. A key finding in that study was that the genus Oporornis, as formerly recognized, was paraphyletic, meaning it included several species that were only distantly related to one another (see also 32 Escalante, P., L. Marquez-Valdelamar, P. de la Torre, J. P. Laclette, and J. Klicka (2009). Evolutionary history of a prominent North American warbler clade: The Oporornis-Geothlypis complex. Molecular Phylogenetics and Evolution 53(3):668–678. Close ). In this case, three of the species were found to cluster relatively tightly with the genus Geothylpis (the yellowthroats), and hence were merged into that genus. This taxonomic change (33 Chesser, R. T., R. C. Banks, F. K. Barker, C. Cicero, J. L. Dunn, A. W. Kratter, I. J. Lovette, P. C. Rasmussen, J. V. Remsen, J. D. Rising, D. F. Stotz, and K. Winker (2011). Fifty-second supplement to the American Ornithologists’ Union Check-list of North American Birds. Auk 128(3):600–613. Close ) left the genus Oporornis with but a single species, and rather than being phylogenetically close to its three former congeners—Geothlypis formosa (Kentucky Warbler), Geothlypis philadelphia (Mourning Warbler), and Geothlypis tolmiei (MacGillivray's Warbler), the sister species of Oporornis agilis is actually the enigmatic Semper's Warbler (Leucopeza semperi) of St. Lucia in the Lesser Antilles, a species that is likely extinct (34 Keith, A. R. (1997). The Birds of St. Lucia, West Indies: An Annotated Check-list. BOU Check-list 15. British Ornithologists’ Union, Tring, UK. Close ). Together, these two species are in turn sister to Geothlypis (31 Lovette, I. J., J. L. Perez-Eman, J. P. Sullivan, R. C. Banks, I. Fiorentino, S. Cordoba-Cordoba, M. Echeverry-Galvis, F. K. Barker, K. J. Burns, J. Klicka, S. M. Lanyon, and E. Bermingham (2010). A comprehensive multilocus phylogeny for the wood-warblers and a revised classification of the Parulidae (Aves). Molecular Phylogenetics and Evolution 57:753–770. Close , 35 Barker, F. K., K. J. Burns, J. Klicka, S. M. Lanyon, and I. J. Lovette (2015). New insights into New World biogeography: an integrated view from the phylogeny of blackbirds, cardinals, sparrows, tanagers, warblers, and allies. Auk 132:333–348. Close ).

McCarthy (36 McCarthy, E. M. (2006). Handbook of Avian Hybrids of the World. Oxford University Press, Oxford, United Kingdom. Close ) cited Sutton's (37 Sutton, G. M. (1967). Oklahoma Birds, Their Ecology and Distribution with Comments on the Avifauna of the Southern Great Plains. University of Oklahoma Press, Norman, OK, USA. Close ) report of hybridization between Geothlypis philadelphia and Oporornis agilis. Sutton (37 Sutton, G. M. (1967). Oklahoma Birds, Their Ecology and Distribution with Comments on the Avifauna of the Southern Great Plains. University of Oklahoma Press, Norman, OK, USA. Close ) opined that a “puzzling” male collected in Muskogee County in eastern Oklahoma (Sam Noble Oklahoma Museum of Natural History 3635), had the black bib of a Geothlypis philadelphia and the complete eye-ring and longer undertail coverts of a Oporornis agilis.

• Connecticut x Mourning Warbler (hybrid) Oporornis agilis x Geothlypis philadelphia

Alexander Wilson first described this species in 1812 and named it after the state of Connecticut in the United States, where he collected the first specimen, a fall migrant. The common name is something of a misnomer, however, because the species does not breed in Connecticut, nor is it a common migrant there.

Information needed.