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ZEISS DTI thermal imaging cameras. For more discoveries at night, and during the day.

BOURC TSC 7th Report (1 Viewer)

Curious, because the paper on identity of vagrant British South Polar Skuas, basically, claims that there is hybridization, differences are subtle and British vagrants couldn't be identified neither on plumage nor DNA. Seems really stringing to call them species, then...

i don't think that's really accurate jurek,

see original discussion here

http://www.birdforum.net/showthread.php?t=27199&highlight=chilensis

the link to the british skua paper is dead now but although there's hybridisation and small amounts of genetic differences between the different southern taxa if i remember correctly it's well accepted that

great skua is genetically quite different,
chilensis is morphologically distinct, while
lonnbergi and hamiltoni are a lot bigger than either maccormacki or antarctica.


I think the only real conundrum in separating the 4 spp suggested by BOU-TSC is IDing juv/subadult type maccormacki and antarctica (adults are quite different i think?).

unfortunately the british types fell in the juv/subadult maccormacki/antarctica camp!! bad luck....

sorry if there's any inaccuracies in there - memories fade after 7 years...

cheers,
James
 
As I read it Saxicola maurus Siberian Stonechat and S rubicola European Stonechat stay together, but both are split from S torquatus African Stonechat.
So Siberian Stonechat is not yet split.

I also read it the way you did. Happy to be wrong though...

Interesting that Cabot's Tern is already on Cat A of the British list, with a (little) bit of digging i think this is due to a ringing recovery of a bird at Newhouse Wood, Herefordshire in November 1984? Anyone got any more info?

Cheers Ian.
 
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Yes, but only if/when proven to be a Cayenne Tern Sterna acuflavida eurygnatha. ;)

Does anyone know what has happened to the assessment of the presumed Cayenne Tern at Cemlyn; it seems to have quietly slipped away. Perhaps the TSC's announcement may renew interest?

BBRC's Race Identification Amongst Changing Taxanomy (RIACT) sub-committee state in their 2006 paper (http://www.bbrc.org.uk/Riact.pdf) that there have been at least 2 records of Cabot's Tern in the UK; anyone have dates / locations of these birds?

Thanks
Phil
 
Cabot's Tern

BBRC's Race Identification Amongst Changing Taxanomy (RIACT) sub-committee state in their 2006 paper (http://www.bbrc.org.uk/Riact.pdf) that there have been at least 2 records of Cabot's Tern in the UK; anyone have dates / locations of these birds?
The British List (7e, 2006) lists only one record:
acuflavida Cabot. One record: Newhouse Wood, Herefordshire, November 1984 (ringing recovery).
Parkin & Knox 2010 (The Status of Birds in Britain & Ireland):
A bird found in Herefordshire in Nov 1984 had been ringed in North Carolina, USA (Mead & Hudson 1986), confirming the occurrence of acuflavida in GB&I.
Garner et al 2007 (Identification of American Sandwich Tern):
There have been two European records of acuflavida, both recoveries of birds ringed as chicks in North Carolina, USA, and found dead later in the same year as first-winters. One was ringed at Cape Lookout on 23 June 1978 and found at Veerse Meer, Noord-Beveland, Zeeland, the Netherlands, on 23 December 1978. Another was ringed as a chick on 25 June 1984 near Beaufort and initially reported by telephone to the British Trust for Ornithology (BTO) as found dead near Hay-on-Wye, Powys, Wales, some time before Christmas 1984. Later investigation revealed that this bird was actually found dead by a Forestry Commission ranger at Newhouse Wood, Herefordshire, on 28 November 1984. This seems an unlikely location for a Sandwich Tern but the finder identified the bird as a tern at the time. Amazingly, this was only the third county record for Sandwich Tern of any subspecies.
 
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Hudsonian Whimbrel

  • Split Numenius hudsonicus Hudsonian Whimbrel from N phaeopus Eurasian Whimbrel.
IOC now lists N hudsonicus as a proposed split, citing Sangster et al 2011.
www.worldbirdnames.org/updates-PS.html [updated 9 Sep 2011]

Recognised by Dutch Birding since Jan 2002, citing Zink et al 1995, Engelmoer & Roselaar 1998.

Recognised by AOU at least up to Check-list 4th edition (1931), but lumped with N phaeopus in 5th edition (1957).
 
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Muscicapinae

Interesting resequence of Muscicapidae genera, but listing only those that the BOURC have dealt with, obviously. I wonder where the remaining genera should be placed. Is there a source for that information?
Mike, BOURC TSC's recommended resequencing of Muscicapinae is based upon Sangster et al 2010 and Zuccon & Ericson 2010 (although the exact sequence adopted is obviously a matter of individual judgement).

  • Sangster, Alström, Forsmark & Olsson 2010. Multi-locus phylogenetic analysis of Old World chats and flycatchers reveals extensive paraphyly at family, subfamily and genus level (Aves: Muscicapidae). Mol Phylogenet Evol 57(1): 380-392.

  • Zuccon & Ericson 2010. A multi-gene phylogeny disentangles the chat-flycatcher complex (Aves: Muscicapidae). Zool Scr 39(3): 213–224.
[Both papers can be downloaded free from SMNH.]

Also taken into account by:
But IOC seems to be waiting for the dust to settle...
 
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Most interesting reply is by Dr. Remsen:

J. V. Remsen said...
Concerning the Whimbrels and the Sandwich Terns, note that the BOU is basing this on a single gene tree -- the branching pattern shown by a single gene. We are learning the hard way that "gene trees" and "species trees" are not necessarily the same thing, as dramatized by Jacobsen and Omland's recent paper on North American orioles and Carling and Brumfield's paper on Passerina buntings. Therefore, bar is being raised rapidly on using single gene trees to change classifications. Also, note that the BOU seems to be applying "bar-coder" logic to these decisions, namely if two taxa differ by more than a certain % sequence divergence, then they are ranked as species. That logic is widely disputed, at least here in North America. As for the Whimbrels, the last I heard was that calls are indistinguishable -- is there any new data on this? If not, then I think they would be the only shorebird species pair that is not diagnosable by calls ... if correct, highly suspicious.
 
I don't feel comfortable with the Whimbrel split yet... Don't East Asian birds have intermediate features?

Depends on what you mean: the opus states that compared with European birds Siberian birds have darker tails and lower rump but white backs, while hudsonicus has back and tail concolorous with the wings.

Niels
 
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