Exploring Short-Term Bird Behavior in a Local Area Using Phased-Array Avian Radar

Radar ornithology traditionally relies on weather surveillance radar systems to study bird migration patterns over large geographic areas and extended timeframes. However, there is a scarcity of information regarding short-term bird behavior in localized regions. Here, we investigate the time budgets of birds of various sizes in Tongguan County within China's Yellow River wetland bird protection area. Employing a Ku-band phased-array radar enhances our ability to efficiently observe radar signals from both small and large avian species. Our observations reveal that small birds dominate the study site, and distinct diurnal variations in time budgets exist between small and large birds, with larger species exhibiting reduced activity during the afternoon. Furthermore, the overlap of signal amplitudes between small and large birds within a single radar resolution cell challenges the radar cross-section (RCS) as a reliable classification signature. This study underscores the potential of avian radar systems utilizing phased-array radar technology as supplementary remote sensing tools for investigating bird behavior in radar ornithology.