Dusky Flycatcher
Encyclopedia
The American Dusky Flycatcher, or simply Dusky Flycatcher, (Empidonax oberholseri) is a small, insectivorous passerine
of the tyrant flycatcher
family.
The Dusky Flycatcher is one of many species in the genus Empidonax. These species are very similar in appearance and behavior, and they are notoriously difficult to differentiate. The best characteristics for distinguishing these species are voice, breeding habitat, and range.
and a bit larger than the Hammond's Flycatcher
.
.
to southern Arizona
and Mexico
. As non-breeding residents in the south of their migration range, they are passage migrants over the deserts of the southwest US
, the Mojave
, Sonoran
, and Chihuahuan Desert
s, where they make their stops along the flyway
.
. They make a cup nest low in a vertical fork in a shrub.
), also sometimes picking insects from foliage while hovering, (gleaning
).
Passerine
A passerine is a bird of the order Passeriformes, which includes more than half of all bird species. Sometimes known as perching birds or, less accurately, as songbirds, the passerines form one of the most diverse terrestrial vertebrate orders: with over 5,000 identified species, it has roughly...
of the tyrant flycatcher
Tyrant flycatcher
The tyrant flycatchers are a family of passerine birds which occur throughout North and South America. They are considered the largest family of birds on Earth, with more than 400 species. They are the most diverse avian family in every country in the Americas, except for the United States and...
family.
The Dusky Flycatcher is one of many species in the genus Empidonax. These species are very similar in appearance and behavior, and they are notoriously difficult to differentiate. The best characteristics for distinguishing these species are voice, breeding habitat, and range.
Description
Adults have olive-grey upperparts, darker on the wings and tail, with whitish underparts; they have a noticeable medium-width white eye ring, white wing bars and a medium length tail. The breast is washed with olive-grey. The bill is mainly dark. It is a bit smaller than the Gray FlycatcherGray Flycatcher
The American Gray Flycatcher, or just Gray Flycatcher, is a small, insectivorous passerine in the tyrant flycatcher family. It is common in the arid regions of western North America, especially the Great Basin...
and a bit larger than the Hammond's Flycatcher
Hammond's Flycatcher
Hammond's Flycatcher, Empidonax hammondii is a small insect-eating bird. It is a small Empidonax flycatcher, with typical size ranging from 12.5-14.5 cm....
.
Vocalizations
The male sings a three-part song. A common call is a dry whit, similar to that of other Empidonax flycatchers. A less common call that is possibly only given by male is a sad dew-hic.Taxonomy
The scientific name commemorates the American ornithologist Harry Church OberholserHarry Church Oberholser
Harry Church Oberholser was an American ornithologist.Oberholser worked for the United States Bureau of Biological Survey from 1895 to 1941, first as an ornithologist, later as a biologist, and finally as an editor. He was the author of a number of books and articles...
.
Distribution
These birds migrateBird migration
Bird migration is the regular seasonal journey undertaken by many species of birds. Bird movements include those made in response to changes in food availability, habitat or weather. Sometimes, journeys are not termed "true migration" because they are irregular or in only one direction...
to southern Arizona
Arizona
Arizona ; is a state located in the southwestern region of the United States. It is also part of the western United States and the mountain west. The capital and largest city is Phoenix...
and Mexico
Mexico
The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...
. As non-breeding residents in the south of their migration range, they are passage migrants over the deserts of the southwest US
Southwestern United States
The Southwestern United States is a region defined in different ways by different sources. Broad definitions include nearly a quarter of the United States, including Arizona, California, Colorado, Nevada, New Mexico, Oklahoma, Texas and Utah...
, the Mojave
Mojave Desert
The Mojave Desert occupies a significant portion of southeastern California and smaller parts of central California, southern Nevada, southwestern Utah and northwestern Arizona, in the United States...
, Sonoran
Sonoran Desert
The Sonoran Desert is a North American desert which straddles part of the United States-Mexico border and covers large parts of the U.S. states of Arizona and California and the northwest Mexican states of Sonora, Baja California, and Baja California Sur. It is one of the largest and hottest...
, and Chihuahuan Desert
Chihuahuan Desert
The Chihuahuan Desert is a desert, and an ecoregion designation, that straddles the U.S.-Mexico border in the central and northern portions of the Mexican Plateau, bordered on the west by the extensive Sierra Madre Occidental range, and overlaying northern portions of the east range, the Sierra...
s, where they make their stops along the flyway
Flyway
A flyway is a flight path used in bird migration. Flyways generally span over continents and often oceans.-Flyways of the Americas:*Atlantic Flyway*Central Flyway*Mississippi Flyway*Pacific Flyway*Allegheny Front...
.
Habitat
Their breeding habitat is mountain slopes and foothills with brush and scattered trees across western North AmericaNorth America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
. They make a cup nest low in a vertical fork in a shrub.
Behavior
They wait on an open perch and fly out to catch insects in flight, (hawkingHawking (birds)
Hawking is a feeding strategy in birds involving catching flying insects in the air. The term usually refers to a technique of sallying out from a perch to snatch an insect and then returning to the same or a different perch...
), also sometimes picking insects from foliage while hovering, (gleaning
Gleaning (birds)
Gleaning is a term for a feeding strategy by birds in which they catch invertebrate prey, mainly arthropods, by plucking them from foliage or the ground, from crevices such as rock faces and under the eaves of houses, or even, as in the case of ticks and lice, from living animals. This behavior is...
).