MacGillivrays Warbler (Oporornis tolmiei )
- Includes information on this bird's nest location and type, breeding, and hybridization with the Mourning Warbler.
- http://www.stanfordalumni.org/birdsite/text/species/MacGillivrays_Warbler.html

Connecticut Warbler (Oporornis agilis)
- Physical traits, migration status, nesting, and taxonomy. Includes a sound file.
- http://www.mbr-pwrc.usgs.gov/id/framlst/i6780id.html

Kentucky Warbler (Oporornis formosus)
- Distribution, habitat, physical characteristics, and nesting behavior of this songbird.
- http://birds.cornell.edu/bfl/speciesaccts/kenwar.html