Vocalisations vs. Appearence in a tricky Leaf warbler

29 04 2015

“If it has more than three chords, it’s Jazz”

– Lou Reed

It was a boring spring. Despite the good numbers of Pallid harrier and Great snipe registered mainly in the Northeastern Catalan coast, the best I had seen in Barcelona area was a “Mediterranean” spotted flycatcher Muscicapa s. balearica/tyrrhenica. Sadly, the bird went away without me being able to take a photo of the underwing.


Yesterday felt just like another random day: some Willow warblers, some Pied flycatchers, a sudden Redstart… nothing too exciting until I got a text from Manolo saying he had found a Yellow-browed warbler in Montjuïc mountain, right in the middle of Barcelona. The bird seemed to be ringed in one of the record shots Lucy managed to take, so we decided to come back late in the afternoon to try to take better photos. Things went actually interesting when Manolo pointed out that he had not heard it a single time giving the typical Yellow-browed call but some Hume’s-like sounds instead. The bird was not cooperative and they had only got poor views and breif vocalisations, but he already got the feeling of a grey bird.

After having seen some Yellow-broweds this spring in the Canary Islands (like the one below), I was aware of how grey they can get when worn, so we both knew we had to focus on sound recordings in order to clarify the identification of the bird.

yellow browed

There were quite a lot of birds in the area, including some nice migrants for  the patch, such as Turtle dove and Golden oriole, but after a couple of hours without relocating the bird, we were sitting in the grass, just chilling, waiting for the other to say we should leave. Suddenly, the bird called behind us, almost in the same tree Manolo had found it in the morning. This time, the call sounded just like a Hume’s leaf warbler! After some search that produced some new birds (at least 2 Western Bonelli’s warblers, either they were not there or it’s incredible how many birds do we miss despite intensive search), we located the bird and managed to take decent photos.



Apart from what looks like an extensively black bill, the rest of the bird looked like what I’d expect from a Yellow-browed by this time of the year: pure white wing bar in the GCs, green tones in scapulars and mantle, well-defined facial marks and a still visible 2nd wing bar in the MCs. However, we both agreed we had heard a Hume’s.

To get a sound recording suddenly turned out to be critical, so we just followed the bird with my cell phone pointing towards it, until it eventually happened. Again, as in the previous 3 times we had heard it, the call was not that of a Yellow-browed and reminded more of a Hume’s. This time, however, we had a recording for a later analyse.

sonogram inor_humei2

As can be seen in the comparison with Hume’s and Yellow-browed (taken from Xeno-canto), it definetely looks (sounds) like Hume’s. After having checked almost all the recordings in this website, I’ve not been able to find a single Yellow-browed with a decrecent end. In the other hand, and despite the high variability described for this species, all the Hume’s end with this downward inflection. To summarize the variation, the standard Yellow-browed call looks, in sonograms, like a V; the standard Hume’s looks like an upside-down W, with the angle of the first V more acute.

So, as Manolo said, “why it’s never easy?” It’s true, we never find a Pelican, we usually have to deal with shy uniform warblers and when they are a nice and barred species, there’s a conflict between call and appearence. Since our experience with Hume’s leaf warbler is low (none in my case!), comments on the bird are more than welcome. In the meanwhile, we’ll wait for the pelican.

PS: Many many thanks to Manolo for cheering up the spring 🙂


Some nice photos

12 03 2015

“This is how the entire course of a life can be changed: by doing nothing.”

Chesil Beach, Ian McEwan

It’s been a busy winter. It’s not that I’ve not had the time to post something on the blog, the problem is that there has been so much stuff going on that I’ve not been able to sum it up. It’s quite easy actually: Borolo’s sheawater things in the Canary Islands and twitching in Catalonia.

The project with the shearwaters is going well and the first two birds have been successfully tagged, both reporting data about their unknown foraging range. Since all the information about this is already in the project’ blog post, I’ll focus on some other experiences. First of all, while trying to mistnet shearwaters, we caught several Grant’s storm-petrels. This species is not formally described yet and… oh wait, Stephen already spoke about that too!

Lanzarote 104

Canarias 360

Should I write about the twitching then? Much ink has been already spilled about the Brown shrike at Ebro Delta, the Isabelline shrike at Marjal d’Almenara, the Pygmy cormorant and the Ring-necked duck at exactly the same locality in Aiguamolls de l’Empordà and the local megas (almost first twitchable ever) Rock pipit and Purple sandpiper (both at Ebro Delta and surrounding areas).


Delta de l'Ebre 147

Catalunya gener 2015 382

So, what’s left? 3 months without posting and you end up showing some lichen photos to add some freshness. Here they go, Lepraria sp. and Xanthoria sp.:

Canarias 099

Canarias 109

Both photos were taken at Fuerteventura. The Eastern Islands are bright like I had never seen them before, both full of flowers that create a stunning carpet. Keeping in mind most of these plants are endemic, the ecological benefits of this year’s rain are invaluable. The photo shows the currently violet surroundings of El Golfo village, due to the flowered Echium lancerottense.

Echium lancerottense4

Echium lancerottense B

Echium lancerottense3

Fuerteventura shows a similar aspect, but what always impresses me the most are the sharp colors of the spurges Euphorbia canariensis. While Stephen was chasing some stonechats, I was taking photos of the scene.

Canarias 042

Canarias 138

So this has ended up being a crappy post with no information and just some nice photos. Trust me, it’s not been that bad…

Quality time

3 08 2014

 “We were right we were giving, and this is how we kept what we gave away.”

– Comes a time, Neil Young

It’s been already a month since all these events happened, but I’ve kept them in my mind since they are gonna be one of the best memories I’d preserve from 2014. After a busy spring  coming and going from Barcelona to elsewhere, it happened that Stephen suddenly came to visit us and I had not got the time to plan the trip properly. Neither had Marc and Martí, and hence we ended up in Vall d’Aran looking for some nice birds/butterflies/orchids but basically spending some quality time together. It was the first time that Marc, Martí, Stephen and me were at the same time in the same spot but I’m pretty sure it’s not gonna be the last one.

The first thing we did was to ring a Rock bunting. Stephen had fallen in love with the species in the very first time he came to Catalonia. Now he is not in a hurry to see everything, we can spend some time to actually look at the birds. As expected, when we caught it and realized it was a boring adult (3+, Euring 6, 2nd cycle, …) Stephen recognized it was not that nice and claimed for a 2nd year. After we had politely suggested him to go and screw himself, we left the area and finally faced the Pyrenees.

The first stop was at a very nice place Marc knew was plenty of Pyrenean brook salamander Calotriton asper. Nice to see them but once you’ve seen one, you’ve seen them all. In case you wonder, it’s Stephen holding the newt in front of his brand new t-shirt he had bought in London airport.

calotriton asper

In Vall d’Aran we saw some Lammergeiers, a Cinereous vulture, Citril finches and quite a lot of orchids. Since Martí is been very into orchids lately, it was nice to learn from him. As I can’t be arsed to make the usual collage that usually ilustrates this kind of paragraphs, I will just post a photo of the one I liked the most: Sword-leaved Helleborine Cephalanthera longifolia.

cephalanthera longifolia

But the best was this Black hairstreak Satyrium pruni: the first record for Catalonia! More on that soon…


After some Black-bellied sandgrouses, whiterby Reed buntings and displaying Red-necked nightjars in Lleida steppes, we came back to Barcelona to target Pekin robin (currently Red-billed leiothrix or something like that). We failed despite there were several singing around. However, we caught a couple of Sardinian warblers and some baby Firecrest that made Stephen happy. So did the omelette and the Iberian ham we got for dinner.

We still had a day to fill up some lagoons: we still needed to see a male Roch thrush. We went to a place near Marc’s area where they used to breed. Nowadays they don’t, but it’s still an interesting Mediterranean bushland area good for Ortolan bunting, Western orphan warbler, Red-rumped swallow, blue rock thrush… We put up the nets and managed to catch a 2cy male Western Orphean, an Iberian subalpine wabler (currently inornata iberiae) and a Red-legged partridge. To finally see a male Rock thrush we had to go up to Turó de l’Home, the highest peak in Montseny mountains. Fortunately, we found one almost immediately and it ended up being the last bird of the trip.

sylvia hortensis

Almost one month later, and just before coming to Sweden, I came back to Vall d’Aran, this time with Laura. The air, the wildlife and the landscapes of this area is perfect for a reset in life. We didn’t look for anything in particular, our only purpose was to be there and forget about the stressful city, without cell phone signal, using electricity only for listening to music. We managed, and now I feel ready for the start of a new ringing season in Falsterbo.

Lycaena virgaureae

Blast from the past

12 08 2013

“Dreams are the genus; nightmares the species.”

– Jorge Luis Borges

It’s been already 5 years with the same idea hanging around in my head. It was in summer 2008, already in July but after a memorable spring migration plenty of eastern migrants. Joan Castelló caught an Acrocephalus warbler at Reguerons, Llobregat Delta, that immediately struck him as being something different. His first impression while extracting the bird from the mistnet was of a cold-toned reed warbler, very small. Later on, already taking the measurements, he thought about Blyth’s reed warbler, especially due to the position of p2. The only problem he could find was, as always, the lack of emargination in p4. The bird showed a hint of emargination, but this is usually present in the subsequent primary to the one emarginated, due to a higher exposure of this part of the feather and therefore a differential level of wear.

We were afraid of the possibility of a Blyth’s with a non-emarginated p4, so we asked both Killian Mullarney and Anthero Lindholm, who kindly replied giving extra reasons for ruling out dumetorum. Both agreed the edges of GCs and the centre of the alula were too warm, the supercilium too colorful and the primary projection too long.

Fine, the bird was not a Blyth’s, but, then, what was it? Neither Joan nor me were happy with just “2cy+ Reed warbler” and, during the last 4 years I’ve been looking at the pictures again and again, without reaching any conclusions. However, the Acro world has been shaken in the last months, especially in its southern boundary. News coming from North Africa talk about resident populations of African reed warbler Acrocephalus baeticatus breeding north of the Sahara, as close to Llobregat Delta as Morocco and Tunisia. By that time this possibility was not taken into account but it’s now worth-considering.

The overall appearance is indeed that of a cold-toned acro, especially the head and the nape but also the upperparts. After a spring ringing in Falsterbo, Sweden, I am aware about how grey a Reed warbler can be, but Iberian birds are much warmer. In that sense, this bird was quite different from the ones usually caught in spring along the Iberian Mediterranean coast. The eyebrow was quite indistinct, something that we knew didn’t fit Blyth’s, and there is a noticeable open-face impression. The bare parts were also striking. Admittedly, the bill is not as dark as described for nominal baeticatus, especially in the under mandible, but the shape is more triangular than in a typical scirpaceus. The legs are much darker, almost even darker than in a juvenile Reed, with a more contrasted yellow sole. These legs would be, in fact, the darkest I’ve ever seen in a 2cy+ Reed.

acrocephalus sp3

The biometrics are the most striking feature. The wing length was 62, in the lower end of Reed warbler range according to Svenson. P2 is surprisingly short, falling between p5 and p6, far from the typical p3-p4 of scirpaceus. The emargination in p3 is very long, taking up 2/3 of the visible part of the feather. Moreover, the notch in p2 is also long, ending below the secondaries; according to Jiguet et al. 2010, the notch should end below p8 in a Reed warbler.  Finally, the wear of the primaries indicates that the tip is p4 and not p3 as typical in scirpaceus.

acrocephalus sp

acrocephalus sp2

All these features fit African reed and rule out Reed but, as always in the acro world, is not that easy! The most misleading thing is that those short-winged birds are quite common in the Mediterranean and Southern Iberia. I’ve caught birds with a wing length of 58 and there are several claims of Blyth’s reed warbler in Southern Spain that were identified based on biometrics. I’ve heard that some of those birds didn’t match all the features for Blyth’s, but this species was the most similar. I wonder if those ringers, as we did 4 years ago, forgot about baeticatus and, lost in Svenson’s bible, didn’t manage to find the answer.

The moult, the song and of course some feather samples should be the key. Although the moult of primaries in breeding grounds is a criteria for African reed warbler, BWPi already gathers some cases of Reed warblers moulting primaries in the Iberian Peninsula, before departing to the wintering grounds. Marc kindly sent me the photo below of a bird in active primary moult caught at Ebro Delta in early September and a bird with a very advanced primary moult caught in Northern Italy also in early September can be seen by clicking here (log in needed). Note that Marc’s bird also shows a suspicious wing formula.


Some evidences points to the fact that baeticatus, or at least baeticatus-like warblers, do occur at least in the south and east of the Iberian Peninsula but further studies are required to confirm this point. Keeping in mind the short distance from the nearest breeding grounds recently described, it wouldn’t surprise me if some birds are found to be breeding. The taxonomic debate may start soon and we shouldn’t be surprised if the final outcome is the description of another clinal variation from North (or even South) Africa to Eastern Asia, this time with Reed warbler as the principal actor.

Photos by Joan Castello © (1, 2 & 3) and Marc Illa © (4)


26 07 2013

“You asked me to dance
Said music was great for dancing
I don’t really dance much
But this time I did”

– Last days of disco, Yo la tengo

After a busy spring season in the field, I took a month for being at home, enjoying the city and the life out of the bubble. However, I got the time to do some birding/ringing/butterflying. Two days of ringing at Castelltallat mountains, in central Catalonia, were so useful to remember about some Mediterranean species. The species set had changed quite a lot since the last time I had ringed there. Instead of the big numbers of both Rock and Cirl buntings that I used to catch, now I got some forest species such as Western Bonelli’s warbler an the less exciting Blackcap and Short-toed tree-creeper. The place has in fact changed quite a lot. The area was burnt in 1998 and since then several new plant species have colonized in a typical vegetal succession sequence. The firsts Strawberry trees Arbutus unedo had already given way to some oak species and the former bush-land area is nowadays an actual forest. Fortunately, some opened areas had survived and there is still a notable density of Ortolan bunting among other interesting Mediterranean species such as Western black-eared wheatear, Rock sparrow, Blue rock thrush and Western orphean warbler. The formerly scarce Golden oriole is nowadays one of the commonest species in what could probably be treated as the paradigm of the overall change.


Another Mediterranean species that seems to be increasing is the Subalpine warbler. The area is now the perfect habitat for the Subalpines: low Quercus in dry areas. I have to say this is one of my favorite species and I’d never get tired of ringing them, especially given the fact that the aging is never straightforward. This time I looked at the tail and tried to assess the age of every feather. Here it is my attempt on 2 birds (one 2cy male and one 2cy female):

Sylvia cantillans tail2

Sylvia cantillans tail

The presence of juvenile feathers is quite obvious in both cases, but the number of generations and the kind of moult that every feather comes from is not obvious at all. However, in my opinion, it’s possible to see the sometimes invisible differences between the first and the second pre-nuptial moults. Here you can see one of the males in all its splendour. Beautiful, isn’t it?

Sylvia cantillans

Another interesting bird I caught was this Nightjar. It’s an adult with a suspended moult: the 3 innermost primaries, the biggest alula and some secondaries are retained in what constitutes a good example of how the presence of 2 generations of feathers (even if there is not a pre-nuptial moult) doesn’t necessarily mean the bird is a 2cy. The pattern of the retained feathers is the same than the moulted ones and the differences are only due to wear. The high frequency of this suspended moult in this species makes me wonder what “suspended moult” means. Maybe we should consider this as a partial moult that both juvenile and adult birds can do. The individuals that do an actual complete are, in fact, an exception!

nightjar wing

The diversity of butterflies around the place where I set the nets was notable. The final list included some scarce species such as Marsh fritillary Euphydryas aurinia and Sloe hairstreak Satyrium acaciae. However, some meadows had been cropped and there were not many flowers. It could had been even better, but some places where plenty of Pyramid orchids Anacamptis pyramidalis, one of the commonest orchids in Catalan mountains.

Satyrium acaciae

Euphydryas aurinia

Anacamptis pyramidalis

Finally, I thought a visit to the Pyrenees targeting the always special Ptarmigans would be a good training session for the cold Sweden. It was really cold high in the mountains, with a strong snowfall and a freezing wind. We managed to see a male Ptarmigan doing some display. Quite stunning! Sadly, there were not many butterflies due to cold temperatures.

Lagopus muta

Lagopus muta2

Lagopus muta3

Now I am ready for another ringing season at Falsterbo. The “Foreign Team” (Stephen and me) and the Southern Gangsters (in alphabetical order: Emil, Oscar and Ulrik) will be ringing at Flommen reedbed until the end of September and then we will move to the lighthouse. The season looks promising: we are already 50 birds above the for-the-time average, we’ve already broken 1 day record (even it’s just the starling day record…) and we’ve already caught a rarity, this Savi’s warbler (yeah, another southern species…; © Stephen Menzie). I will sound like a twitcher, but I felt it was nice the species number 200 in my Swedish list was a rarity. Anyway, all of this in just 5 days of ringing; it looks promising but it’s still too early to take conclusions. Let’s see.


Southern colors

19 06 2013

“I try to apply colors like words that shape poems, like notes that shape music.”

– Joan Miró

It was really warm at 5 o’clock in the morning and the (Common) nightingales were already singing. Just one hour later, the Golden orioles joined them while the Alpine swifts and the Bee-eaters started to fly over. Cetti’s, Sardinian warbler, Short-toed tree-creeper, Long-tailed tits with a black head, Green woodpeckers with a grey face… Mediterranean, in the end!


It was a day of ringing, of course, but it was also the day of the reencounters. After more than 3 months in Sweden, the differences were even more noticeable. It had been around 2 years without going to Abrera, a good river woodland surrounding the Llobregat river, around 25 km inland from the river mouth. The place was completely different from what I did remember and I realized how dynamic these ecosystems are. Depending on the floods or the droughts, the shape of the river (and therefore the shape of the forest) varies from one year to another. The ecological succession had also played its role and some cane’ areas had turned into poplars and tamarinds.

What never changes at Abrera is the diversity in the captures. Firstly, we caught 3 wrynecks, one of them being a downy young. The probable parents (all three were in the same net at the same time) were both 2cy, one of them with this nice moult limit in the secondaries. Sometimes is not easy to assess the pattern and the wear of the primary coverts, so the secondaries are also worth-looking.

retained SS jynx

After a couple of net rounds with short-toed treecreepers, nightingales and green woodpeckers, we caught a very nice Bee-eater. It has retained all the primary coverts in the left wind, but in the other it has replaced one. To be honest, I’ve lost practice with Bee-eaters and what I remember is the difficulties I used to have while judging the primary coverts. This bird was extremely useful to compare juvenile and adult feathers side-by-side.


replaced pcc

The last colorful bird was a Hoopoe. The crest was worn, like in most punks nowadays, and so were the tertials and the primaries. However, the bird lacked the obvious contrast shown by the 2cy Hoopoes in Marc’s blog. Actually, the old secondaries in both Marc’s hoopoes and in this one are still glossy and the age of each feather can be really hard to tell. However, the width of the white bands seems to be a good evidence of where the moult limit is and if we trust it, this bird shows what in my opinion is a moult limit. The width of the white fits with a slightly browner color in the outer secondary, especially in the basis of the feather. The shape of the tip is also quite different, being more square-shaped in the adult feather.

Upupa head

SS upupa

If I want to keep on learning about these species, time is money and I can’t stay at home.


Not yet in Sweden, I promise

24 02 2013

“I grow up in Chicago, and there was always snow. In Los Angeles there never was, so we would always import snow!”

– David Hasselhoff

I woke up yesterday morning with the sound of the snow heavily falling outdoors and for a moment I thought I was already in Sweden. My mother suddenly appeared to take me back to reality and then I realized I may be still in Barcelona. So… What to do? This badly-timed cold front is too late for an influx of northern wildfowl, so the only effect it may have may be a noticeable sedimentation of early spring migrants.

Finally, I decided to visit the Llobregat Delta, a good place for both migrants and wildfowl. The firsts views of the landscape were pretty unusual, with the plain surrounded by white mountains. It was cold, but there was no wind, so the conditions were almost perfect to do some birding.


There were quite a lot crag martins flying over the Cal Tet lagoon and, among them, my first house martin. A pied wagtail had been sighted a few hours before, but I didn’t manage to find it. Moreover, it was plenty of wildfowl: more than 80 red-crested pochards, 300 shovelers, gadwalls, some shelducks, hundreds of teals, mediterranean, black-headed, yellow-legged and an Audouin’s gull… but the best was this female ferruginous duck, a bird always nice to see.


A greater spotted cuckoo (also my first this year) flushed at Cal Nani marshes did demonstrate that spring is already in the air. The bird showed well, sat on a fence for a while and later moved to the top of a blackberry bush.


We don’t have much time left till the arrival of the bulk of swallows, willow warblers and subalpine warblers, but let’s see where do I am when this happens.

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