• Vincent

Early May I spent a week on the lovely island of Sardinia. I was of course keen to see Balearic Shrike, the endemic west Mediterranean island ssp (badius) of the Woodchat Shrike.

Now I'm learning by thinking out loud here, so comments are welcome.

The most important difference with the other 3 ssp. is - of course - the (near) lack of a visible white primary patch: about 2/3 of all birds have no white patch at all when perched, 1/3 shows a limited amount on the inner primaries only.

I think visible is a key word here. But first things first.

Here are some pics of the nominate ssp. senator, the default taxon in most parts of Europe. Note the obvious white patch on the primaries.

Woodchat Shrike ssp. senator, 2nd cy female, Rhodopi Mountains, Bulgaria, May 2009

Woodchat Shrike ssp. senator, 2nd cy male, Lesvos, Greece, May 2012 (note the large mask; aged i.e. by the brown juvenile lesser coverts)

Woodchat Shrike ssp. senator, 2nd cy (the unmoulted primary coverts give away this bird's age), Lesvos, Greece, May 2012

Other subtle differences include the colour of the cap (more orange red instead of chestnut in badius), the - on average - darker wing (due to narrower white fringes on the coverts) and the size of the black mask (smaller in badius) and bill (larger in badius). For ID details see Small & Walbridge (2005) or this summary on Surfbirds.

Woodchat Shrike ssp. senator, adult male, Sardinia, Italy, May 2018 (note the funky little detail in the outer tail feather!)

The first Woodchat Shrike I saw on Sardinia seemed to lack a white primary patch. Even though the cap was rather chestnut, the mask on the forehead wasn't very broad and the bill didn't look smallish. With what I saw, combined with the location, I thought I had a full bingo card. But I made the call too early!

When it took off (ok, I came too close), this is what I captured:

That's not a little white I missed, that's a massive wing bar! In hindsight the wing patch must have been obscured: 'overlaying' secondaries sometimes cause confusion.

So this bird was a migrating senator (ok, technically the Iberian ssp. rutilans could not be excluded) instead of the desired Balearic Shrike.

A few more Woodchats were present on the beautiful Capo Ferrato, like this 2nd cy male. The mask is small. The bill: not very deep perhaps, but the cap is orange red.

But look at the outer primaries. Though somewhat faint, there's still a fairly large amount of white visible. Another senator in disguise in badius territory that on a larger distance perhaps could have been misidentified!

And then there was this adult female. There's no white wing patch and the bill looks quite heavy. There are hardly any pale fringes on the coverts. All looked good for badius!

Then it took off. Hey, perhaps it's not that much, but there's certainly more white visible on the base of the primaries than I expected!

So is this acceptable for badius in flight? Well, I guess so...

I saw this individual on 3 days, from many angles and I never saw a wing patch when it was perched. Apparently the white is shorter than the primary coverts (and was therefore obscured when perched).

Boy, it's annoying that our national museum of natural history is closed for renovation for 2 yrs. I'd love to lift some primary coverts on badius, to see what's underneath.

In any case it was obvious that even within its range, a careful look was still needed to ID Balearic Shrike.

#BalearicShrike #badius #WoodchatShrike #Sardinia

  • Vincent

I just spent a lovely week on Sardinia. The recently split Mediterranean Flycatcher (Muscicapa tyrrhenica tyrrhenica) is pleasantly common there.

It seems to occur in a much wider range of habitats than Spotted Fly in NW Europe. From macchia to hill forests and from quiet farmland with scattered trees to village gardens: they seemed to be everywhere below the tree line.    

They differ from Spotted on plumage, biometrics and genetics (see Viganò and Corso 2015). I indeed had the impression that on average they were paler and less spotted below, but note that some were more marked than others, while on the other hand less well-marked Spotted Flycatchers can be found in NW Europe.

For now I reckon we are still a long way off to identify a potential vagrant in NW Europe with certainty.

The "Spanish" Med island ssp. balearica seems to differ a tod more from Spotted, with a pale speckled crown. Check out Marc Illa's wonderful website for more details and an instructive pic.

The birds on Sardinia were very vocal:


A quick comparison with five recordings of Spotted Fly on xeno-canto slightly suggests that the calls I recorded are on average slightly higher pitched, though I have no clue about individual variation (and with high pitched calls the quality of the recordings certainly plays a role), so it might be nothing at all.  

My recording of the alarm call is rather poor, but I couldn't find any obvious differences. I never heard its song. 

Word is on the street that Viganò and Corso are about to finish a new piece on this taxon that includes calls. Something interesting to look forward to, cause I hope to learn a bit more about these birds! 

#MediterraneanFlycatcher #Sardinia #birdidentification

  • Vincent

First proof that it's the nominate subspecies of Hume's Leaf Warbler that reaches Europe.

Aerobics, the final countdown and warbler taxonomy

Back in the 80s, Hume's Leaf Warbler was still considered a ssp. of Yellow-browed Warbler. Since then not only our hair fashion and taste in music has improved, but also our insights in leaf warbler taxonomy. There are significant genetic, morphological and acoustic differences between the two and acoustic experiments in overlapping breeding ranges show that these species basically ignore each other (Irwin et al 2001). So: different species. No discussion.

But what about Hume's Warbler ssp?

But Hume's Leaf Warbler has two ssp: humei and mandellii. These two ssp. also differ genetically, morphologically and acoustically. Whether you call them species or subspecies, depends a bit on the species concept you prefer (Irwin 2001). The nominate breeds in mountains in the northern part of the Indian Subcontinent, Central Asia, S Russia and Mongolia, while Mandelli's Leaf Warbler has an isolated range in C China, 1500 km away from the nearest breeding Hume's. Hume's winters around the Indian Subcontinent, Mandelli's in SE Asia. Mandelli's is somewhat browner, with a greyer cap, it usually has no upper wingbar and it often has some yellow in the eyebrow and on the underparts (Clement 2017). The genetic distance between the two ssp. is much smaller than between Hume's and Yellow-browed. Hume's and Mandelli's have two song types: a "double note" and something vaguely reminiscent of a squeaky V-belt. The double note slightly differs since it's a bit higher pitched in Mandelli's. Mandelli's als has a higher pitched call. Acoustic experiments however show that Hume's and Mandelli's respond to each other's vocalisations (Irwin et al 2001).

The acoustic experiments are enough reason to regard them as ssp. and as far as I know not a single world list has split them. It's likely that they are in the process of becoming separate species, but are just not there yet.

Figure 2. Genetic variation between Yellow-browed, Hume's Leaf and Mandelli's Leaf Warbler, including the bird ringed in Meijendel.

So what about the vagrants in Europe?

Due to their respective ranges, it's of course the nominate ssp. that most likely shows up in Europe. Both the plumages and calls of Dutch birds I checked also imply that. But I think it has never really been sorted out. So Peter de Knijff analysed some feathers I collected of the bird I trapped on 7 November 2017 in Meijendel, Wassenaar, the Netherlands (the bird on top of this post). The analysis proofs that, as expected, it was indeed a humei. This is the first genetic proof of this subspecies in Europe (Martin Collinson in litt). See figure 2 (made by Peter de Knijff).

No surprises here, but at least we have now established with certainty that humei is the default taxon in Europe.

More details will be published in a Hume's Leaf Warbler overview in Dutch Birding magazine later this year.

Acknowledgements

Martin Collinson confirmed no other humei has been genetically tested in Europe before. Peter de Knijff is once more thanked for his genetic analyses. Peter made figure 2.

References

Irwin, D E , P Alström, U Olsson & Z M Benowitz-Fredericks 2001. Cryptic species in the genus Phylloscopus (Old World leaf warblers). Ibis 143: 233-247

Clement, P 2017. Hume's Leaf-warbler (Phylloscopus humei). In: del Hoyo, J., Elliott, A., Sargatal, J., Christie, D.A. & de Juana, E. (eds.). Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona.

#geneticanalyses #HumesLeafWarbler

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Arnhem AEB413

18 October 2014, Meijendel, Wassenaar, the Netherlands

© 2018 by Vincent van der Spek