Southwestern Willow Flycatcher (Empidonax traillii extimus) is a small (13-17 cm) songbird that is found in the southwestern U.S. and northwestern Mexico, mostly occurring in New Mexico and Arizona. They are riparian-obligates with territories in areas of willows (Salix spp.) and/or salt cedar (Tamarix spp.), in the immediate vicinity of standing water. They are threatened by Brown-headed Cowbird parasitism and habitat loss and degradation due to water and land management that modifies their riparian habitats.