Nevada Fish & Wildlife Office
Pacific Southwest Region

Southwestern Willow Flycatcher
(Empidonax traillii extimus)

Class: Aves
Order: Passeriformes
Family: Tyrannidae
Genus: Empidonax
Species: traillii
Subspecies: extimus
Length: 5.75 inches
Weight: 0.42 oz
Wingspan:: 8.5 inches
 

Nesting:

May-June
Number of Eggs: 2-5
 

Official Status:

Listed Endangered in 1995

 

Life History:

This subspecies has a grayish-green back and wings, whitish throat, light gray-olive breast, and pale yellowish belly. Two wingbars are visible; the eye ring is faint or absent. The upper mandible is dark and the lower is light. The most distinguishing characteristic between the southwestern willow and other willow flycatchers is their song, a sneezy “fitz-bew”.

The southwestern willow flycatcher is present in breeding territories by mid-May. It builds nests and lays eggs in late May and early June (average clutch size is 2 to 5 eggs) and fledges young in early to mid-July. Second clutches only occur if the first clutch failed. Between August and September, the southwestern willow flycatcher migrates to wintering grounds in Mexico, Central America, and possibly northern South America.
The southwestern willow flycatcher is an insectivore and forages within and above dense riparian vegetation. It catches insects while flying, hovers to glean them from foliage, and occasionally captures insects on the ground.

 

Distribution and Habitat:

 

The breeding range of the southwestern willow flycatcher includes southern California, Arizona, New Mexico, extreme southern portions of Nevada and Utah, far western Texas, perhaps southwestern Colorado, and extreme northwestern Mexico. In Nevada this subspecies can be found along the Virgin River, lower Muddy River, Colorado River, and Pahranagat Valley.


The southwestern willow flycatcher breeds in relatively dense riparian tree and shrub communities associated with rivers, swamps, and other wetlands including lakes and reservoirs. In most instances, the dense vegetation occurs within the first 10 to 13 feet above ground. Habitat patches must be at least 0.25 ac in size and at least 30 feet wide. Historically the southwestern willow flycatcher nested in native vegetation including willows, seepwillow, boxelder, buttonbush, and cottonwood. Following modern changes to riparian communities, this subspecies still nests in native vegetation, but also uses thickets dominated by non-native tamarisk and Russian olive, or in mixed native non-native stands. The flycatcher builds a small open cup nest, most often 6.5 to 23feet above ground in a fork or on a horizontal branch of a medium-sized bush or small tree with dense vegetation above and around the nest.


Threats:

 

This species has declined because of removing, thinning, or destroying riparian vegetation; water diversions and groundwater pumping which alter riparian vegetation; overstocking or other mismanagement of livestock; and recreational development. In addition to above threats, the southwestern willow flycatcher is also subject to cowbird parasitism.

 

Fun Fact:

  Empidonax flycatchers are almost impossible to tell apart in the field so biologists use their songs to distinguish between them.
 

Actions / Current Information:

01/02/2013
  • News Release-Service Identifies Important Habitat for Recovery of Southwestern Willow Flycatcher New Info
     
  • Frequently Asked Questions and Answers Critical Habitat Revision New Info
     
  • Federal Register - Designation of Critical Habitat for Southwestern Willow Flycatcher (9.6MB PDF)New Info
    07/11/2012
  • Fish and Wildlife Service Seeks Input on Southwestern Willow Flycatcher Critical Habitat Proposal
     
  • Southwestern Willow Flycatcher Critical Habitat Proposal Questions and Answers
    08/12/2011
  • Endangered and Threatened Wildlife and Plants; Designation of Revised Critical
    Habitat for Southwestern Willow Flycatcher
    (4.2MB PDF)
     
  • Southwestern Willow Flycatcher Critical Habitat Proposal Questions and Answers
    07/09/2007
  • Programmatic Safe harbor Agreement for Voluntary Enhancement/Restoration Activities Benefitting White River Springfish, Pahranagat Roundtail Chub and Southwestern Willow Flycatcher Within Pahranagat Valley, Lincoln County, Nevada
     
  • Attachment 1: Pahranagat Valley Map
     
  • Attachment 2: Landowner Cooperative Agreement Template
     
  • Attachment 3: Landowner Certificate of Inclusion Template
    10/19/2005
  • Federal Register: Endangered and Threatened Wildlife and Plants; Designation of Critical Habitat for the Southwestern Willow Flycatcher (Empidonax traillii extimus) (1.5 MB PDF)
     
  • Map: General Locations of Critical Habitat for the Southwestern Willow Flycatcher (Virgin / Pahranagat Management Units)
     
  • Map: General Locations of Critical Habitat for the Southwestern Willow Flycatcher (Pahranagat Management Units)
     
  • News Release: Service Designates Critical Habitat for Endangered Southwestern Willow Flycatcher
     
  • FAQs - Southwestern Willow Flycatcher

     

    Last updated: April 16, 2014