Mandt’s Guillemot in the Netherlands

Monster!

Martin Garner

A first summer Mandt’s Guillemot was found in the Netherlands two days ago. The subject of one of the chapters in the next Challenge Series, due out in a couple of months, the timing of its appearance couldn’t be better!

2cy Mandt's Guillemot by Corstiaan Beeke

2cy Mandt’s Guillemot by Corstiaan Beeke

A Great Find

Tom van der Have emailed over the weekend to point out a summer plumaged Black Guillemot which had been found by Roger Pynaerts at Kamperland – Jacobahaven on the southern Dutch coast (east of Essex and Kent). The bird seems only to have ben present on Saturday 27th June and not yet seen since. Tom was quick to note it showed characters of mandtii

Corstiaan Beeke and Pim Wolf got lovely photos, demonstrating beyond doubt this was indeed no ordinary Black Guillemot. In fact it’s a first summer Mandt’s Guillemot from the High Arctic.

It’s already in the next Challenge Series: WINTER

We have looked into this subject on Birding Frontiers with this excellent piece from Dan Brown. In preparing the next Challenge series book on ‘Winter’, it seemed an obvious chapter to include. Having gone into the subject in-depth it’s fantastic to have a Mandt’s appear in the southern North Sea up just  couple of months before publication. We guessed they should occur- then one shows up with immaculate timing:). This bird widely touted as mandtii on Talkin Tarn, Cumbria in December 2013, unfortunately appears from the photos to be a paler than average southern bird. In the pictures it lacks critical features of mandtii. I have seen similarly pale birds in Shetland. So Britain awaits its first…

2cy Mandt's Guillemot by Corstiaan Beeke

2cy Mandt’s Guillemot by Corstiaan Beeke

Full Species?

It seems worth commenting that originally Mandt’s Guillemot was consider a full species including by the normally conservative American Ornithologists Union. Its morphology stands in contrast to the southern taxa which vary little, all being very similar. Indeed despite some purported differences among southern taxa, I found none which were robust. One could almost simply have two ‘Black Guillemot’ taxa- the souther ‘grylle’ type and High Arctic mandtii.

2cy Mandt's Guillemot by Corstiaan Beeke

2cy Mandt’s Guillemot by Corstiaan Beeke

Key Features – a section from the new book

To explain why this is a Mandt’s Guillemot- here’s a sneak preview, just for you, from the new book in the Challenge Series: You’ll have to wait though for Ray Scally’s excellent illustrations and some lovely photos 🙂

Key features all plumages

       Underwing

  1.  In southern taxa, primaries largely dark contrasting with white underwing coverts. Some have short white ’bleed’ visible at the base of the primaries. On mandtii white covers about half of the underside of the primaries, slightly less so on birds from Alaska. Secondaries similarly white-based (black in southern taxa) with white visible beyond underwing coverts.Outer upperwing
  2. White patterning in primary coverts is diagnostic for mandtii with greatest extent found in 1cy-2cy. White, to varying degrees on the median and greater primary coverts produces bars across these coverts. In adults the outer primary coverts are typically black but inner primary coverts are white, frequently on inner webs or outer webs or both. In some (adults) white is restricted to innermost median primary coverts and forms just small ‘bud’ of white pushing across into the median primary coverts. In others (and especially first-winters) there are one or two broad conspicuous white bars across the primary coverts almost to leading edge of wing.
  3.  White tipped secondaries (diagnostic formandtii) obvious in1cy-2cy birds and present to varying degree in adultsInner upperwing
  4. Pattern of white patch over secondary coverts (the big white oval) similar in mandtii to southern taxa except that feathers more often wholly white (or almost so) in mandtii, versus being black- based in southern taxa. Black bases are sometimes visible as a dark ‘wingbar’ across white oval patch in adults. Thought to be a feature of islandicus, it is found in other southern taxa also.
  5.  In 1cy-2cy mandtii the black spotting on white upperwing patch is generally smaller than in southern taxa
2cy Mandt's Guillemot by Pim Wolf.

2cy Mandt’s Guillemot by Pim Wolf.

2cy Mandt's Guillemot by Pim Wolf.

2cy Mandt’s Guillemot by Pim Wolf.

In the UK anytime now?

With a fly-by Black Guillemot off Portland last week and a bird which I saw off South Landing, Flamborough also last week (frustratingly distant) – we really need to be on full alert in the UK for this this taxon 🙂

Hope you enjoyed the read… Now to get back to polishing off this flippin book!

2cy Mandt's Guillemot by Pim Wolf.

2cy Mandt’s Guillemot by Pim Wolf.

 

 

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