Family Tyrant-flycatchers (Tyrannidae)

Least Concern

Willow Flycatcher (Empidonax traillii)


French: Moucherolle des saules German: Weidenschnäppertyrann Spanish: Mosquero saucero

Muscicapa traillii


, 1828,

Arkansas River, USA


See E. albigularis. Formerly considered conspecific with E. alnorum. Geographical variation in plumage, wing morphology and vocalizations probably clinal, birds becoming browner overall in W and paler in more arid environments, and racial boundaries not well defined; in recent study#R, plumage coloration and genetic variation (mtDNA and nuclear loci) did not support recognition of race extimus; species sometimes treated as monotypic. Proposed race campestris (North Dakota, in N USA) included in nominate. Four subspecies currently recognized.

Subspecies and Distribution
  • E. t. adastus Oberholser, 1932 – SW Canada (S British Columbia) S in USA to E California (E of Sierra Nevada) and in Great Basin and Rockies; winters mainly W Mexico S to Costa Rica.
  • E. t. traillii (Audubon, 1828) – S parts of Canada (Alberta, Saskatchewan, Ontario, Quebec) and NC & NE USA; winters mainly Panama to Ecuador#R.
  • E. t. brewsteri Oberholser, 1918 – extreme SW Canada (SW British Columbia) S, W of Cascades, to SW California (W of Sierra Nevada); winters probably mainly W Mexico S to Panama.
  • E. t. extimus A. R. Phillips, 1948 – SW USA (SW Utah to S California and W New Mexico); presumably winters W Mexico S to mainly Costa Rica#R.
  • Descriptive notes

    13·3–17 cm; 11·3–16·4 g. Nominate race has indistinct narrow pale loral area, whitish eyering; rest of head drab olive, slightly darker than... read more


    Common call a mellow upslurred “whuit”, “whit” or “whik”, by... read more


    Breeds in variety of moist shrubby habitats, often near water: include wet to dry upland and... read more

    Food and feeding

    Arthropods; occasionally fruit. Recorded items include bees and wasps (Hymenoptera, including Ichneumonidae), beetles (Coleoptera,... read more


    Late May to Jun. Nest-site selected by female; nest a woven cup of stems, bark shreds, dry grass, plant fibres and pine needles, lined with... read more


    Long-distance migrant; winters in S Mexico, Central America and N South America, rare S to NE... read more

    Status and conservation

    Not globally threatened (Least Concern). Overall population estimated at 3,300,000 individuals; conservation plan aims at increasing total numbers by at least 50%. Fairly... read more

    Recommended citation

    Farnsworth, A. & Lebbin, D. (2019). Willow Flycatcher (Empidonax traillii). In: del Hoyo, J., Elliott, A., Sargatal, J., Christie, D.A. & de Juana, E. (eds.). Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona. (retrieved from on 6 December 2019).