AjaA

Po Toi seawatch 9 April 10-12.30 from the south point:

Red-necked Phalarope 191 going east, 283 going west
Unidentified large gull 1 east
Long-tailed Skua 1 east
Arctic Skua 6 east
Unidentified skua 4 east
Unidentified tern 2 east
Cattle Egret 8 east
Little Egret 2 east, 1 north
Unidentified white egret 8 east
Oriental Pratincole 3 east
Whimbrel 1 east

Peregrine 2
Blue Rock Thrush 1 male philippensis 1 female
Chestnut-eared Bunting 1

Brendan can continue from here as he spent the rest of the day at the south point. We spent some time elsewhere.

[ Last edited by AjaA at 9/04/2012 21:13 ]

AjaA

Pics of Short-tailed Shearwater and Dollarbird. A big thanks to Geoff for letting us stay with him. Quite an experience in many ways! We enjoyed it very much indeed.

[ Last edited by AjaA at 27/04/2012 13:07 ]

AjaA

Here are a few more dark pixels of the shearwater.

AjaA

The singing Arctic Warbler close to the upper school seems to really have been an Arctic Warbler, borealis (not examinandus or xanthodryas) - based on both song and call. The attached recordings are of poor quality, because of much other noise and because the bird sang very quietly, but still the call can be heard to be very sharp and the song consists of very similar syllables repeated many times.

Comparison recordings can be found here:

http://www.slu.se/sv/centrumbild ... lers-vocalizations/

and the article seen here:

http://www.nrm.se/download/18.63 ... c+Warblers+IBIS.pdf

[ Last edited by AjaA at 29/04/2012 19:22 ]

AjaA

Our personal experience of autumn mingrating Arctic Warblers is very restricted. But in this species the call is often a part of the song. It could be possible that the double call is "more song", uttered by individuals with breeding activity coming. In young of some Phylloscopus warbler species autumn calls are sometimes different from the normal ones, but this seems not to be the explanation here.

AjaA

Alström et al 2011, The Arctic Warbler Phylloscopus borealis – three anciently separated cryptic species revealed, Ibis (2011), 153, 395–410:

about the song of examinandus:
"It was easily distinguishable from the songs of borealis and kennicotti by the pumping rhythm, which resulted from the presence of usually two different syllable types (A and B) arranged in phrases (usually AAB)"

and about the song of xanthodryas:
"The song resembled that of examinandus, but generally sounded slower, lower-pitched and less sharp and harsh, and the rhythm was clearly different as a result of additional A syllables (e.g. AAAB), or the presence of more than two syllable types in the phrases"

So the main distinction between songs of borealis and examinandus/xanthodryas seems to be that borealis has only one type of syllable in its song, the other two have two or more types.


Song 1. Borealis. Bolshoye Betyu, Komi Republic, Russia 23 June 2006.
Note the syllable structure AAAAA...

Song 2. Xanthodryas. the first song example of Per Alström's web page ("semi-randomly" 1,7 sec of the recording). The syllable structure is AAAABAAB

Song 3. The Po Toi bird. The syllable structure is again AAAAA...

Note also how much faster the Russian and Po Toi birds are (15 and 17 syllables respectively in 1,7 secs) compared to the xanthodryas example with 8 syllables

It should be remembered that the migrants in the earlier stages of spring migration quite often do not sing full songs (their songs are softer than full territorial songs, not fully crystallized). Very good examples in Hong Kong are the singing Dusky Warblers, which have a variable but generally clearly different song compared to Siberian ones. In this case the main distinction seemed to be that the Po Toi bird sang very quietly.