Saturday, July 07, 2007

It's a bird... it's a plane. No, it's a moving goalpost. And a new Percy.

The title refers to my lucid and thought provoking, if not a little arrogant, post on Birdforum here. So the data I was thinking of and hinting at has now been published online here by Louis Bevier. I'd been trying to suggest that people who were defending the IBWO-identity of the Luneau bird by wingbeats 4-8 and the different processing of the Luneau and Nolin videos in my paper were grasping at broken straws and moving the goalposts to defend an untenable point of view, whereas any sensible interpretation of the data would be that the Luneau video was a Pileated. Hiding behind science when for once common sense was enough. BUT Louis has driven the message home by providing the 4-8 wingbeat data and mimicking as closely as possible the video capture and processing of the Luneau video. I agree with Cyberthrush... the Luneau video is dead, but if you believe the reported sightings you don't need the Luneau video. Is it possible for so many people to be so wrong? Random but not entirely unrelated leap... this is a very educational historical piece from the Jourdain (eggers) Society journal about Moustached Warblers, which were added to the British List on the basis of a breeding pair + kids well watched by a crowd of British birding glitterati in Cambridgeshire, later taken off the British List after being shown to be so much wishful thinking and autosuggestion. Provided by Bob McGowan**... pity the poor old eggers, who aren't doing any harm but are unjustifiably persecuted by the RSPB.

**... who also found a new Percy for CaMPaGULAN... Percival Taverner... of Canada ornithology fame. From here...

Taverner, Percy Algernon, ornithologist (b at Guelph, Ont 10 June 1875; d at Ottawa 9 May 1947). Taverner first earned a living as an architectural draughtsman while studying birds in his spare time. In 1911 he was appointed ornithologist at the National Museum of Canada, where he developed a unique system of distributional maps linked to card indexes on individual species containing up-to-date information on bird distribution in Canada. Taverner played an important part in Canadian ornithology and in wildlife conservation, such as the designation of POINT PELÉE as a national park (1918) and the protection of Bonaventure I and Percé Rock in the Gulf of ST LAWRENCE as bird sanctuaries (1919). His ornithological writings culminated in Birds of Canada (1934). Comprehensive and readable, with coloured illustrations by Allan Brooks, it did much to develop a better understanding of ornithology and make birdwatching a popular recreation.

He is 'honoured' by Taverner's Canada Goose. Genetically a small Canada, morphologically a big Canada, probably total bollocks. Taverner's Canada Goose - we salute you!


Bill Pulliam said...

Sorry, dude, but my goalposts haven't moved and Bevier didn't even take a shot at them. I've never been on about the wingbeat RATE, it's been the whole geometry/mechanics of the wingbeats. It's possible you didn't catch that wingbeat rate is virtually irrelevent to my flight mechanics arguments? I realize my stuff is splattered all over my blog in a thousand disjointed postings. Seems to me all I said about flap rate was "maybe a pattern, no statistical meaning, need more data." Bevier didn't touch the meat of my points. He might have the data in his videos that will change things on that front, but he only discusses flap rate and doesn't present any frames that show flap mechanics. As for the plumage stuff, he didn't touch my arguments either: that all he is looking at are highly predictable and explainable edge artifacts which he is mistaking for plumage features. Or, in the case of frame 350, a very dubious effort to interpret the patterns on wings that are not fully extended, using an assumption that they are fully extended.

If this is all the secret data you had lurking in the back of the freezer, it doesn't add much of anything from where I stand. I need someone to show me a video of a Pileated flying the same way; not the same flap rate, but the same strongly-bowed wings for more than just the first flap or two after launch. And they have to actually present the video, not just say they have it. Then we have something more to talk about.

Goalposts right where they were, shot was not taken in their direction.

dnolin said...


You just saw a distant hawk but are unsure of its identity or even genus. Overcast skies make field marks difficult to discern. Hmm, unidentified hawk. Then you notice it is flying with a flap-flap-soar pattern. Aha, accipiter.

The point is that how a bird flies can be very important to bird identification if we have some understanding of it. It seems clear to me that the flight mechanics of the Luneau bird is very different from a pileated woodpecker. It seems like a lot of experts are saying "buteo" when the thing is doing flap-flap-soar.

stephen said...

Hi Bill, dnolin (and Martin),

I believe that IBWOs would fly with the same wing mechanics as other Campephilus Woodpeckers - what do you think? So, do the South and Central American Campephilus woodpeckers fly with bowed wings or not?