DVOC Main Page > Ornithological Studies > Western Emp


by Adrian Binns 06/05

Two of these three western empids usually pose an identification problem – Hammond’s and Dusky.
Empid is short for empidonax which comes from the Greek empis “a gnat’ and anax “king” therefore meaning “king of the gnats”


Hammonds (E. hammondii)

Dusky (E. oberholseri)

Gray (E. wrightii)


L 5.5 WS 8.75

L 5.75 WS 8.25

L 6 WS 8.75


Small and compact empid, smallest of the 3; large headed with little neck showing weightlifter fashion; short tailed and long primary projection; flicks wings and tail quickly upwards, simultaneously

Intermediate in shape and shape between Hammonds and Gray; not as compact as Hammonds with longer tail and shorter winged look and rounder headed; flicks tail quickly upwards, with less wing flicking than Hammonds and with less frequency

Largest of the 3, largest empid; their short primary projection and longer tail give them a stretched out look; perched birds dip their tails down slowly, like a Phoebe; often perches low flying to the ground to pick up insects

Bill and lower mandible

Very small and dark; slightly shorter, thinner and darker than Dusky

Partly dark, orange at base of lower mandible blends into dark tip; bill slightly longer than Hammonds

Long narrow bill; lower mandible mostly pinkish-orange at base, sharply divided from dark tip; a few show entire pinkish-orange

Head shape

Slight crest / peak

Rounded head

Proportionately small and rounded

Overall color

Grayish head and throat; grayish-olive back; often shows a contrast between gray head and olive back; gray or olive wash on breast and sides, give it a distinct vest; belly tinged with pale yellow

Grayish-olive above with whitish throat; yellowish below; pale olive wash on upper breast

Gray above; whitish below


Grayish throat

Whitish to pale gray throat

Whitish throat


White-eye ring; usually expands to a teardrop at rear and thinnest at the top

White-eye ring though sometimes not that conspicuous, because the head is not very dark

Inconspicuous white eye ring on pale gray face

Primary coverts


Show only a slight color difference, if any, between the very narrow tips or edges and their centers

If unworn, have tips or edges that are conspicuously paler than their centers

Primary projection

Longer primary projection than Dusky, giving it a short tailed look

Short primary projection, shorter than Hammonds, giving it a long tailed look

Short primary projection


Narrow, slightly notched tail is edged with gray; lack of whitish outer edge of rectrix should prevent confusion with either Gray or Dusky; medium length, shorter than Dusky; always notched

Narrow and slightly longer than Hammonds, shorter than Gray; whitish outer edge; tip squared or notched

Long tail with thin whitish outer edged rectrix that should separate it from Hammonds

Fall birds

In fresh plumage during fall migration; brighter olive above and on sides of breast; yellower below

In early fall they look pale, worn and drab; fresh late fall birds are quite yellow below

Grayish above with slight olive tinge in fresh fall plumage; belly washed with pale yellow by late fall

Juveniles 1st fall (july-feb)

Distinctive with quite bright yellow bellies that contrast with a dusky-olive wash to the sides of the breast, giving it a vested look; Rather dark olive breast and back contrasts with gray head and a pale gray throat


Brownish-gray above, with pale buffy wingbars; underparts are tinged brownish-buff


Molts (july-aug) before they leave the breeding grounds

Molt occurs after fall migration

Molts in fall after arriving on the wintering grounds


Coniferous (spruce, Douglas fir) forests and aspen; usually higher in mountains than Dusky; prefers cooler surroundings

Open woodlands; low chaparral; mountainside brush where tall conifers meet leafy thickets, or in aspen groves

Dry open habitat; sagebrush; pinyon pine-juniper

Migration pattern

Most migrate earlier in spring and later in fall than Dusky; males migrate north earlier than females

Arrives on breeding ground mostly in May and departs mostly in August

Short distance migrant; some arrive on breeding ground in April and on wintering ground in August

Call note

A sharp peek

A dry whit, softer than Gray.

A dry whit


A series of rough notesof 3 phrases resembling Dusky, chpit.brrrrk.griip but hoarser and lower pitched; never included high clear notes of Dusky

A clear 3 part tsyruptsurpseep; higher than Hammonds

2 phrases, rough emphatic jr-vrip with a high whistled tidoo; also chuwip

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