Scope and Method of Study. Several species of breeding birds in the Eastern Deciduous Forest reach the southwestern limit of their distribution in the mountains of eastern Oklahoma. One of these species is the declining Cerulean Warbler, once reported as at least a locally common breeder in portions of Oklahoma. Recent work for Oklahoma's (1997-2001) breeding bird atlas however, did not document any breeding Cerulean Warblers in the state. Our objective was to search areas of potentially suitable habitat within the historical range of Cerulean Warbler in Oklahoma, and determine if the species still breeds within the state. We conducted point counts at 150 sites in both the Ozark Highlands and the Ouachita Mountains in Eastern Oklahoma in 2006 and 2007.

Findings and Conclusions. We located Cerulean Warblers at 5 out of 150 (3.3%) of the sites surveyed. These sites were located on north slopes in the Ouachita Mountains, near ridge tops between 641 and 721 m elevation. We encountered 8 adult males and 4 adult females at the 5 sites. We confirmed breeding in Oklahoma from separate observations of one pair carrying food and feeding fledglings in June 2006 on Lynn Mountain, Leflore County and another pair feeding fledglings in June 2007 on Rich Mountain, Leflore County.