Verification of Unusual
Sight Record
For Utah
Rec. # 2015-18
Common name: |
Pacific-slope Flycatcher |
Scientific name: | Empidonax difficilis |
Date: | 5/24/15 |
Time: | 10:24 am |
Length of time observed: | 10 minutes |
Number: | 1 |
Age: | |
Sex: | |
Location: | Lytle Ranch |
County: | Washington |
Latilong: | (37.0933, -113.9493) |
Elevation: | 1100 m |
Distance to bird: | 10 feet |
Optical equipment: | Pentax ED 8x43 |
Weather: | Partially Cloudy |
Light Conditions: | Decent, not too harsh light. |
Description: Size of bird: | Typical empid sized |
(Description:) Basic Shape: | Flycatcher |
(Description:) Overall Pattern: | Yellowish with darker olive back |
(Description:) Bill Type: | Broad and flat |
(Description:)
Field Marks and Identifying Characteristics: |
It has been long suspected that the Western Flycatchers migrating through
southwestern Utah are Pacific-slope rather than the regular Utah breeder,
Cordilleran Flycatcher. Migrants in lowland desert migrant traps in nearby
Arizona and Nevada are considered to be Pacific-slope which seem to prefer to
migrate in lowlands. Cordilleran Flycatchers on the other hand seem to favor
migration routes through the mountains. Nate Brown and I found this bird south of the first pond north of the ranch. It looked like a typical Western with a yellowish overall coloration with a yellowish throat, all yellow under the bill, pointed eyering and a raggedy crest. The bird was initially silent so we tried to get it to call to record the voice as this is the best way to tell apart these species. Upon playing a Pacific-slope Flycatcher song, the bird responded for the first of two times. I got a recording of this call and uploaded it to xeno-canto: http://www.xeno-canto.org/246195. The call from the bird is the upward slurred whistle. The other call note, the explosive ptik, is the 3rd part of the Pacific-slope Flycatcher song. The whistle matches the slurred up call of a Pacific-slope Flycatcher rather than the two parted Cordilleran call note. The sonogram image also better matches the sonogram of Pacific-slope which dips down in pitch before continuing rising rather than Cordilleran which tends to be two parted. Here are a look at the sonograms: My bird: http://www.xeno-canto.org/sounds/uploaded/RFTTZSXEUF/ffts/XC246195-large.png Western Washington PSFL 1: http://www.xeno-canto.org/34289 Western Washington PSFL 2: http://www.xeno-canto.org/107694 Vancouver PSFL: http://www.xeno-canto.org/184696 Prescott, AZ COFL: http://www.xeno-canto.org/137920 Colorado COFL 1: http://www.xeno-canto.org/184030 Colorado COFL 2: http://www.xeno-canto.org/70047 |
Song or call & method of delivery: | Slurred upward one note whistle characteristic of Pacific-slope Flycatcher |
Behavior: | Typical flycatching. Excited responded to Pacific-slope Flycatcher song and called upon hearing it. |
Habitat: | Desert Riparian. |
Similar
species and
how were they eliminated: |
The only other species to consider is Cordilleran Flycatcher which looks almost exactly the same. The best way to identify Western Flycatchers to species is through their songs and calls and this call matches a Pacific-slope call as shown in the sonograms above. |
Previous
experience with this & similar species: |
I have heard Pacific-slope Flycatchers in Seattle and have a decent amount of experience with Cordilleran flycatchers on breeding habitat in Nevada and Utah. |
References consulted: | Xeno-canto, Sibleys. |
Description from: | From photo(s) taken at the time of the sighting |
Observer: | Kenny Frisch |
Observer's address: | 4609 S Wallace Ln Holladay, UT |
Observer's e-mail address: | ** |
Other observers who independently identified this bird: | Nate Brown |
Date prepared: | 5/28/15 |
Additional material: | Photos Audio recording. Sonogram |
Additional_Comments: |