Verification of Unusual Sight Record
For Utah

Rec. # 2015-24

Common name:

Pacific-slope Flycatcher

Scientific name: Empidonax difficilis
Date: 8/23/15
Time: 8:57 am
Length of time observed: Observed: 30 sec
Number: 1
Age: ?
Sex: ?
Location: Lytle Ranch
County: Washington
Latilong: (37.0933, -113.9493)
Elevation: 2800 ft
Distance to bird: 25 feet
Optical equipment: None
Weather: Partially Sunny
Light Conditions: Decent, not too harsh light.
Description:        Size of bird:  
(Description:)       Basic Shape:  
(Description:)  Overall Pattern:  
(Description:)            Bill Type:  
Field Marks and
Identifying Characteristics:
I did not visually observe this bird as it was hidden in a tree. I recorded its song as soon as I heard it singing.
Song or call & method of delivery: Song was a 3 part sequence- tsip, klseewii, ptik. The ptik note had the first syllable lower than the second (which is the reverse of a Cordilleran.
Behavior: Sung for about 15 seconds before going silent.
Habitat: Desert riparian.
Similar species and how
were they eliminated:
Cordilleran and Pacific-slope are identical in appearance. The only sure fire way to tell them apart is by voice. Earlier in May I recorded a call note of a Pacific-slope, which is hard to differentiate from a Cordilleran. Looking at the sonogram of the call, it shows that all 3 elements of the song match up with a Pacific-slope Flycatcher rather than a Cordilleran.

I uploaded my song to xeno-canto so I could view the sonograms.

Here is a sonogram of the song of my flycatcher:

Here is a song of a PSFL from near San Diego:

Finally a sonogram of a COFL from Colorado:

[Here's the unedited recording;]

Visually, the first note of a PSFL just rises vs rising and falling in a COFL. The second note of a PSFL sharply rises before abruptly dropping and then rising sharply again; with a COFL the second note has a longer first rise with it curving down and then briefly rising again. Finally the 3rd note of a PSFL looks like a straight up and down line with the 3rd note of a COFL showing 2 parts.

More research is needed but it would appear that Pacific-slope Flycatcher is an uncommon migrant through desert lowlands of southwestern Utah where as Cordilleran Flycatcher prefer to migrate in highlands.

Previous experience with
this & similar species:
I have seen and heard Pacific-slope Flycatchers several times before in Washington and Utah.
References consulted: Sibley's 2nd edition. Xeno-canto
Description from: Notes 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:  
Date prepared: 8/25/15
Additional material: