Empidonax traillii extimus NatureServe Explorer Species Reports — NatureServe Explorer is a source for authoritative conservation information on more than 50,000 plants, animals and ecological communtities of the U.S and Canada. NatureServe Explorer provides in-depth information on rare and endangered species, but includes common plants and animals too. NatureServe Explorer is a product of NatureServe in collaboration with the Natural Heritage Network.
ITIS Reports — ITIS (the Integrated Taxonomic Information System) is a source for authoritative taxonomic information on plants, animals, fungi, and microbes of North America and the world.
FWS Digital Media Library — The U.S. Fish and Wildlife Service’s National Digital Library is a searchable collection of selected images, historical artifacts, audio clips, publications, and video. The southwestern willow flycatcher ( Empidonax traillii extimus) is a riparian obligate neotropical migrant, nesting in cottonwood-willow associations and structurally similar riparian vegetation associations. The southwestern willow flycatcher (Empidonax trailii extimus) is one of four subspecies of Empidonax trailii in the family of tyrant flycatchers (Tyrannidae). The three other willow flycatcher subspecies occupy different breeding ranges in the U.S. adjacent to the southwestern subspecies, with E. t. adastus to the north, E. t. trailii to the east, and E. t. brewsteri to the northwest along the northern Pacific coast.