Image from the Biodiversity Heritage Library.
Contributed by Museum of Vertebrate Zoology, University of California, Berkeley.
| www.biodiversitylibrary.org
Transcription
Holmes, R.
1963
C. canatus
4.
13 June Opoforuk Creek, Cape Thompson, Alaska
The introductory notes were not always given when I was there - They were soft + difficult to hear. The fast whistled phrase (twe-twee) was given 4-10x. This was followed by one-10 slow-phrases.
Case 2: The slow phrases were given first
The few (#?) fast phrases - followed by 1 slow phrase
The alarm note - as mentioned before -
was a fort wha-wak-wak - or an emphatic - wha-ack - who-welz, wha-ack
This song was given in flight and usually just prior to landing. One - flight a shallow arc was noted when the song was given - but there was no hovering or quivering wings.
When landing, the singer would glide into the level and outstretched, down-curved wings - alight, keep down wings at the vertical for ½ second - before lowering them into mand folded position. This was noted twice & at the time when they showed - the wings were held up very briefly.
17 June Birds located again (no mummy)
The "Canyon" nut-wet / the north of Crowder -
where I went yesterday. The