Wednesday, April 18, 2007

Brown or South Polar?

I guess I don't keep very up to date with the news services, but is this slipping under the community radar? The two unusual Skuas in Scilly and Glamorgan in 2001 that were identified on the basis of a combination of mtDNA and plumage as Brown Skua (Votier et al., 2002) have been subjected to reanalysis following isolation of new South Polar Skua mtDNA sequences from the Antarctic peninsula (Votier et al., 2007). This has shown that Brown and South Polar Skuas cannot be reliably distinguished on the basis of mtDNA, so although the birds were definitely NOT Great Skua, they could have been either Brown or South Polar. And let's face it, betting men, they were probably South Polar. So if you had it ticked off in your Birdwatch 'Complete Checklist' of British Birds, you might have ticked too soon. Shame really - no one did anything wrong here, it's just science. You get data, make conclusions, then get more data to test those conclusions and see if they stand up. Sometimes they don't - c'est la vie.

'Southern' Skua, Scilly 2001. Photo by Dave Hatton.
Previously published in Birding World vol 15 page 386.

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