Over the last few weeks I've developed a rather obsessive fascination with trying to discover/identify a spring overshoot/vagrant Mediterranean Flycatcher Muscicapa striata balearica (or M. t. balearica, depending on whether or not you accept the recent split) and it's been really interesting. It's been quite challenging but I found, what appear to my eyes, to be some really nice looking candidates. The taxonomy is rather confusing as is the field identification but I will summarise, to the best of my abilities what I have read/learned so far.
What are they?
To keep things simple, the IOC have recently split Mediterranean Flycatcher, from Spotted Flycatcher, and recognises two subspecies of Mediterranean Flycatcher, namely:
- M. t. balearica, which is known to breed only on the Balearic Islands
- M. t. tyrrhenica, which breeds primarily on Corsica & Sardinia
What are the field characteristics?
Here is a summary of features in my own words based on a series of papers, blogs and webpages I've found online. As I am birding in Catalunya, I'm focusing only on balearica for now.
- Crown streaking: Crown is often noticeably marked with prominent white streaks (ground colour), as opposed to the normal brownish/greyish streaks of Spotted Flycatcher.
- General paler/greyer appearance. Spotted Flycatcher appears warmer/browner.
- Highly reduced/lack of streaking on breast: Typical Spotted Flycatchers tend to be heavily streaked in comparison to the clean white breast (some times with more blotchy minimal streaks in upper-breast) of balearica.
- Shorter primary projection: The 2nd primary falls between 5th & 6th in balearica, and 4th & 5th in striata
- White underwing coverts: Clean white underwing coverts seem to be an important clinching feature. This contrasts to the darker ochreous/brown tinged underwing coverts of striata. Just how important, and how variable this is, I do not know and I'm hoping to see some skins somewhere soon to make some sense of this in my own head. I think this is very difficult to judge in the field and good photos in correct lighting are absolutely vital. If the wing is backlit or the underwing coverts are at an angle whereby they are shaded, the resulting photo can be misleading and make them look darker than they actually are.
Occurrence in Catalunya
Catalunya is well placed to receive overshoots of the species, and it does so every year. I can't give an exact figure but it seems there are a reasonable number of birds found each year, with 17 birds reported on ornitho.cat in 2019, at the time of writing. From mid-April of this year there was a steady passage of Spotted Flycatchers through Delta del Llobregat, and I photographed individuals which showed characteristics of M. t. balearica. I have isolated 3 individual birds, which in my eyes look promising.
M. t. balearica Candidate 1:
This bird was photographed on 30/04/19 at Remolar Filipines, Delta del Llobregat. Unfortunately the bird remained in the shadow of a pine tree for the short period where I could photograph it, at a moderate distance.
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| White ground colour, presenting white streaks on forehead, general pale colouration and general lack of streaking on breast first made my stop and photograph this individual. |
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| White underwing coverts visible, although shade/lack of direct sunlight taking from true clarity of white |
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| White underwing coverts visible again |
This bird was photographed close to sunset La Murtra, Villacecans on 05/05/19. Again, this was a very pale, clean looking bird which attracted further attention immediately. In the field, in failing light it was very difficult/nearly impossible to assess the underwing coverts, but the pictures appear to show a clean white underwing.
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| A pale looking, unstreaked Muscicapa sp. |
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| White underwing coverts apparently visible. |
M. t. balearica Candidate 3:
This bird performed really well and looked really nice in the field. I recorded it on 09/05/19 at Can Dimoni, Delta del Llobregat. It allowed a close approach in good light and it seems to tick all of the boxes. It's pale, unstreaked, with an apparent short primary projection, pale head-streaking, and a white underwing. Unfortunately my underwing shots are not really good but they seem to illustrate the point.
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| A very promising bird: pale, unstreaked, with an apparent short primary projection & pale head-streaking |
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| Underwing looking pale/concolourous with clean white belly |
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| Again, underwing looking promisingly white |
Conclusion:
I think, to claim these with any certainty outside of their usual range, at least until further studies are released one needs to be very cautious, and take good photos and/or notes. The potential for vagrancy into NW Europe must certainly be a possibility, if you consider the number of Catalan records per year, and the fact the badius Woodchat Shrike can and has made it, further strengthens this. If anyone has any thoughts on any of the birds featured here, I would love to hear from you!
Available Resources:
Everything with this species/subspecies is still a work in progress but there are some nice papers and write-ups out there for those interested. Below is a summary of what I have found online, not organised in any particular manner.
Some very nice comparative pictures taken by Marc Illa:
http://birdingmarc.blogspot.com/2013/05/balearics.html
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Pons, Jean-Marc & J.-C, Thibault & Aymí, Raül & Marcello, Grussu & J, Muntaner & Olioso, Georges & Sunyer, Josep & Touihri, Moez & Fuchs, Jérôme. (2015). The role of western Mediterranean islands in the evolutionary diversification of the Spotted Flycatcher (Muscicapa striata), a long-distance migratory passerine species. Journal of Avian Biology. 47. 10.1111/jav.00859.
https://www.researchgate.net/publication/283459683_The_role_of_western_Mediterranean_islands_in_the_evolutionary_diversification_of_the_Spotted_Flycatcher_Muscicapa_striata_a_long-distance_migratory_passerine_species
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A very brief summary with some nice images here:
https://norfolkbirdtours.wordpress.com/tag/mediterranean-flycatcher/
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A very informative writeup with excellent comparative images by Andy Butler, here:
https://andybutlerdiaries.blogspot.com/2018/07/some-observation-on-adult-mediterranean.html
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Viganò, Michele & Corso, Andrea. (2015). Morphological differences between two subspecies of Spotted Flycatcher Muscicapa striata (Pallas, 1764) (Passeriformes Muscicapidae). Biodiversity Journal. 6. 271-284.
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Gargallo, Gabriel. (2019). Identificació de la subespècie balear de menjamosques (Muscicapa striata balearica). Anuari ornitològic de les Balears: revista d'observació estudi i conservació dels aucells; Núm.: 8.
https://www.researchgate.net/publication/39387438_Identificacio_de_la_subespecie_balear_de_menjamosques_Muscicapa_striata_balearica
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