Some observations on adult Mediterranean Flycatchers on Corsica

Following DNA and morphological studies of Spotted Flycatchers on Corsica, Sardinia and the Balearic Islands published in 2015 (see footnotes for references) the International Ornithological Congress (IOC) split the species into Spotted Flycatcher and Mediterranean Flycatcher with the latter including the nominate Muscicapa tyrrhenica tyrrhenica and the Balearic Island subspecies M t balearica. In January 2018 the BOU adopted the IOC World List for taxonomic purposes and therefore the Mediterranean Flycatcher is a potential addition to the British list. 

This has not been universally accepted and some authorities still treat tyrrhenica and balearica as a race of striata, including the just published Handbook of Western Palearctic Birds by Shirihai & Svensson.

Whatever the ins and outs I'm interested in geographical variation and so a trip to Corsica in July was an opportunity to have a look at the flycatcher for myself. 
The Mediterranean Flycatcher is common on the island and I saw them in the mountain villages to at least 1000m and down to sea level. On the coast the breeding density was particularly high and I had 3 pairs in a 400m strip of pines close to where I was staying.

Generally Mediterranean Flycatcher appears a warmer brown without the grey tones of striata and the breast has less distinct dark streaks and appears more blotchy. In some lights the upper breast can appear almost unstreaked. The effect of the light was very significant, birds looking much browner and less streaked in the strong Mediterranean sun and greyer and more streaked in shadow.

Photo 1 Mediterranean Flycatcher - left in sun, right in shade

Both the above photos are of the same bird taken straight from the camera without any adjustment, other than a little sharpening. Post processing adjustment particularly to the highlights have a big impact on how distinct the streaking appears and on the plumage tones.

Photo 2 Mediterranean Flycatcher as above with post processing adjustments

So the lighting conditions are important when assessing colour and the extent of breast streaking, as is the photo post processing when looking at images.

Photo 3 Mediterranean Flycatcher (left) v Spotted Flycatcher (right)

Photo 3 shows the extent and strength of the breast streaking on the two species. Note how brown the Spotted looks in the sunlight compared to Mediterranean in the shade. The bill looks slightly thicker on Spotted, having a slightly more swollen appearance?
There may be slight differences in the streaking of the crown and nape but I couldn't see anything consistent.

Perhaps the most significant quoted difference between the two species is primary length with Spotted generally having the primary extension greater than the exposed tertials whilst in Mediterranean the primary extension is less than the exposed tertials. This is very difficult to assess in the field and is best done from photographs but they are very dependent on the angle and stance of the bird and also on the condition of the feathers.

Photos 4 & 5; Mediterranean Flycatcher estimation of primary extension (Note lower bird has very worn longest tertial)

Photo 6; Spotted Flycatcher estimation of primary extension (© Ken Smith)

The paper by Michele Vigano & Andrea Corso gives a range of wing measurements and demonstrates that Mediterranean Flycatcher has a shorter wing length, on avarage by 4.6mm,  and more rounded wing. Differences in the primary spacing on the closed wing could therefore be apparent, in the article the most significant difference found was between the longest primary p3 and p2 which unfortunately isn't visible on the closed wing.

Photo 7; Mediterranean (L) v Spotted Flycatcher (R) primary spacing

Apologies if I have the primary numbering incorrect. On the Spotted Flycatcher p3 is longest but this is variable and it doesn't look to me as if there is any obvious difference which would help in the field.

Photo 8; Mediterranean Flycatcher in a typical view, length of the primaries compared to the undertail coverts doesn't appear to help in separating the species presumably due to posture factors

Both Corso & Vigano have stated on BirdForum that an article on the identification of Mediterranean Flycatcher, or Tyrrhenian Flycatcher as they prefer, is in preparation for Dutch Birding. I no longer subscribe but don't think this has been published yet? Andrea Corso also stated that the 'call is clinching too' on BirdForum but didn't elaborate. The Mediterranean Flycatchers were generally vocal and the call was consistently a high pitched seeep usually ending with a tchak. In the UK I most commonly here the seeep alone but have also heard the seeep - tchak. The birds in Corsica were feeding young which may have influenced their calls. I haven't analysed the calls to see if there is any quantifiable difference in frequency. I made a recording which is available below.

In conclusion I think a Spring flycatcher with warm brown tones to the upper parts and subdued breast markings, comprised of brownish blotches rather than distinct dark streaks would be worthy of closer inspection and a primary projection of less than the exposed tertials would be a strong indication of Mediterranean Flycatcher. 
M t balearica is paler and has a slightly shorter wing length (BWP) than nominate tyrrhenica so the features described above should be slightly more obvious in that race of Mediterranean Flycatcher.
If there is a vocal difference that would be an additional factor and possibly a clincher to quote Andrea Corso. 
All the flycatchers are interesting and worth a close look in any case.

Michele Viganò & Andrea Corso; Morphological differences between two subspecies of Spotted Flycatcher Muscicapa striata (Pallas, 1764) (Passeriformes Muscicapidae). 

Biodiversity Journal, 2015, 6 (1): 271–284

Pons et al ; 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(3) · November 2015

Corsica 2nd - 9th July

Pam and I travelled to Corsica on the Moby car ferry departing Livorno at 08:00 and arriving in Bastia at around 12:30 on 2nd July. The ferry crossing was fairly quiet with just half a dozen sightings each of Scopoli's and Yelkouan Shearwaters. We immediately headed for Corte in the mountains where we stayed for 3 nights.

The following morning I headed south stopping for an hour at the Fortin de Pasciola accessed from just beyond Vivario which quickly provided the calls of both Moltoni's and Marmora's Warblers but rather poor views of each. I carried in the direction of the Col de Sorba stopping about 3km from the T20/D69 junction. 

Corsican Pines

It was very quiet by the roadside but a short walk south on a rough track and I soon heard the distinctive almost Jay like call of the Corsican Nuthatch (42 .1497222 17.30556). The call is difficult to describe, so here is a recording made at the time (this doesn't always play with Safari as the browser but works fine with Google Chrome).

I was surprised at how small they were, smaller than Kruper's Nuthatch and looking particularly small in flight. Getting photographs proved tricky as they stayed close to the top of the pines and were hidden much of the time. Watching a male for a prolonged period he spent much of the time hunting on the underside of the branches and I was surprised when it stopped and spent several minutes preening whilst hanging upside down, bat like!

Corsican Nuthatch - male

Whilst watching the nuthatches several Crossbill flew over as did several parties of Corsican Finch and I decided to try for photos of these and return to the nuthatches later. 

Corsican Finch - male

They are much yellower on the underparts and browner on the back than their mainland counterpart the Citril Finch. The mantle of some males is the colour of a Linnet. 
The following morning I returned to the nuthatches and quickly found them again in the same area. There were at least 5 but could have been more. Other birds in the area included Jay, Great Spotted Woodpecker, Cirl Bunting and Blue, Coal and Great Tits plus several Mediterranean Flycatchers.

Corsican Nuthatch - female

I then followed the track further up the hillside, which after another 400m revealed a scrubby area off to the right which looked ideal for Marmora's Warbler, and so it was. I spent several hours in the area and had at least 7 birds with several males in song. They spent most of the time deep in the scrub and were often invisible, even when only a few metres away but eventually I managed some rather distant photos of a male bird which stood briefly on a rock. Although I have seen Balearic Warbler several times on Majorca these were my first Marmora's Warblers since I saw Britains first record on Midhope Moor in 1982. It would be something to find one on my local Beeley Moor.

Marmora's Warbler - male

Leaving the mountains we headed to the coast at Calvi. It was very warm, with day time temperatures in the low 30's, so between around 10:00 and 17:00 it was difficult bird watching and generally unproductive. On the way we stopped at a beach just to the north of Calvi where a pair of Red-rumped Swallow were nesting in a beach cafe.

A Jay at the campsite came to visit the bins and proved more co-operative than many of that species, it is a separate race on Corsica but like many of the races looked very similar to the birds in the UK.

European Jay 

In a 500m stretch of pines by the coast I found at least 3 pairs of Mediterranean Flycatcher, another recent split and Corsica/Sardinia speciality. I spent several hours watching and photographing them and will do a separate blog post on these observations.

Mediterranean Flycatcher

A bushy area at the edge of town held at least one pair of Sardinian and Moltoni's Warblers with the latter still singing.

Moltoni's Warbler - male

Moltoni's Warbler - female

Sardinian Warbler - female

Further up the coast we stopped at Saint-Florent, on the way a female Red-backed Shrike with at least one juvenile was seen on roadside wires.

Saint-Florent

The campsite had both Nightjar and Scops Owl calling but I didn't see either. A late afternoon walk in to the hills to the west of town produced almost nothing but the same walk in the early hours of the following morning yielded Nightingale, Moltoni's and Dartford Warbler plus Cirl Bunting, Common Buzzard, Woodlark and Blue Rock Thrush.

Cirl Bunting - adult female

The other feature of Corsica, unlike the rest of France is that all the sparrows are Italian and the starlings Spotless.

Italian Sparrow - Male upper, Juvenile lower

The commonest dragonfly was Southern Migrant Hawker which were anywhere with a bit of standing water.

Southern Migrant Hawker

All in all a very successful and enjoyable trip, a bit cooler and fewer flies and mosquitoes would have been perfect.
We left Corsica again on the Bastia - Livorno ferry and again saw a small number of shearwaters.

Scopoli's Shearwater

The ferry was so well camouflaged I'm surprised we didn't see more from it!

Moby Ferry