The western wood pewee (Contopus sordidulus) is a small tyrant flycatcher. Adults are gray-olive on the upperparts with light underparts, washed with olive on the breast. They have two wing bars and a dark bill with yellow at the base of the lower mandible. Adults measure 5.5 to 6.3 inches in length. These birds may be spotted in the COSA from May to June and August to October