I was hiking in this mostly section of the Santa Clara Riverbed, with members of the Channel Islands Animal Tracking team that morning. One of the visual animal encounters we had that day were of a pair of Lesser Nighthawks that we accidentally startled as we passed through the dense scrub near the stream. They spent several minutes flying around, until they finally calmed down and retreated back into the scrub. One of the trackers believed that the nighthawks may have been a breeding pair, and that we may have been near their nest when we startled them.
Lesser Nighthawk (Chordeiles acutipennis), Mayflower County Park, Riverside County, California - 20 May 2014. Calling (trill) and then seen overhead just before sunrise.