Friday, January 31, 2014

Turtles

No!, although I quite like them, I'm not gonna talk about turtles. I've been wondering why the hell Turtle Doves (Streptopelia turtur) are called 'Turtle', and the conclusion is (I found it somewhere on Internet) that 'Turtle' means something about the call.

Well, the thing is that the other day, after the GS Eagle photo session, we visited a Turtle Dove that was found there in December.
  

When I saw the bird, some contrasts between wing coverts attracted my attention. I remembered some birds that I trapped in Menorca in spring last year with apparent moult limits in coverts, but in this case, it really seemed an actual moult limit. The bird flew soon, and I wouldn't bother it anymore, so this thing remind in my head.
There's always a difference in colour
between scapulars and wing coverts.
Already at home, I looked for this interesting post, in Alex Ollé's blog, where he discusses some points about Rufous Turtle Dove ID and this bird. In the end of the page, he have some photos where I could see some more things.

As the bird had obvious worn retained primaries I started thinking about a 1w, but I needed to look for information to can say something, I'm not used to age this birds in winter. Cramp et.al. (1985) say that adults undergo a complete postbreeding moult that sometimes can be suspended or started in winter quarters (so not finished in the breeding areas). Those birds that suspended its moult had between 1 and 4 inner primaries, but there were checked just a few birds in this study (Swann and Baillie 1979). Also, the major part of these birds did a partial body moult and then migrated. Juveniles do a complete postjuvenile moult, also with big variation in terms of timing. As Cramp says, some birds that had hatched earlier do a suspended moult in autumn, with 1-4 inner primaries new and some body feathers also replaced. But later-hatched birds usually migrate in fully juvenile plumage, and sometimes start with primaries still growing! (look, as an example as later-hatched, this 1st-year in 20th September, migrating but still with all plumage juvenile)

After the postjuvenile moult, a few birds can retain 1-2 outer primaries, and usually one or more secondaries. Baker (1980) says another interesting and useful character to age in spring: the tip of the outer median primary coverts, that usually are covered by the alula. These feathers are tipped brown in 2nd-years, but grey-blue in adults (as the rest of wing coverts). In my experience some birds can just have one or two median PC tipped brown, but we can assume is enough to age these birds as 2nd years.
Tip and colour of median primary coverts. Left: 2nd-year spring, right: adult.
Three retained secondaries in a 2nd-year (spring)
One secondary retained, shorter and with paler tip.
2nd-year spring
Adult in spring
Going back to the Aiguamolls bird, the contrast in the wing coverts should indicate that this bird did a partial body moult before migration. The retained wing coverts are obviously not juvenile pattern, so I think that for this, the bird can be aged safely as an EURING 6. Looking on Internet, I've found this first-year with some wing coverts moulted. The retained ones are clearly different.
Photo by Àlex Ollé
Then, the extension of moult has confused me a bit, but also support the EURING 6 theory. It seems that the Aiguamolls bird had moulted 7 primaries, and initially I thought that also all secondaries, thing that was a bit weird for me. Looking photos of the wing with proper resolution, I reckon that some secondaries seems to be also retained, but they are apparently as long as the moulted ones, and not with a very pale tip.

Photos by Àlex Ollé
I want to say thank you to Àlex Ollé, for his photos and helpful comments, and to Raül Escandell for the great time we passed together in Menorca where I learnt about Turtle Dove and other migrants. Also, thank you to other members of SOM (Ornithological Society of Menorca) that make thing like the spring ringing campaign possible!

Wednesday, January 29, 2014

Clanga, finally

Last 17th November, a first-year Greater Spotted Eagle (Aquila clanga) was found in Pals, in NE Catalonia, by Gerard Dalmau and Miguel Ángel Fuentes. I remember that day quite rainy, and I thought that eagle would fly south during the following days... For many years, a satellite radio-tracked individual from Estonia has crossed Catalonia beucause he has been overwintering in Alacant, many kilometres south of Catalonia (more information here).

Nonetheless, the bird stayed many days where it was found, and then it started to move around the Catalan coast, reaching Llobregat Delta, dissapearing some days and going back to Pals later. Finally, the bird turned up in Aiguamolls de l'Empodà natural park, until at least yesterday.
I've read many interesting things about this bird, written by Àlex Ollé and Guillermo Rodríguez. Firstly, this comparation (in Catalan) of the sightings from Pals and Llobregat Delta, showing that was the same bird. And secondly, this fantastic discussion (in Spanish) about 'western GS Eagles', hybrids with LS and what this bird seems to be.

After seeing that bird many times in my laptop, and after reading all this interesting things, I really wanted to see that bird. So yesterday, Ferran Fitó and me went there to try it. The bird had been seen the day before in the Matà meadows, so we went there straightforward. Some minutes after arrive, I saw a raptor flying quite far. I found it with the scope... and yes, I finally was seeing the GS Eagle with my own eyes.
I had read that it should be a male because it's an small
individual. I understood it perfectly when I saw it flying with
 this Marsh Harrier...
It started to get closer, but still far for good photos, although I was really happy just seeing it!

Then, the bird change its direction and came straight to us. It flew just above us, and then it crossed Matà meadows again. A really nice way to assess all that features that I wanted to see in this bird! And also a good chance to get acceptable photos.


The rest of the day didn't produce anything special. Many birds were just the same I saw on December, like this Flamingo (Phoenicopterus roseus), just in the same place doing exactly the same.


The Canada x Barnacle Goose and the 2 first.winters Greater White-fronted Geese (Anser albifrons) were in the Cortalet laggon, but I didn't saw the Bean Goose that had been there during the last month. Maybe, the only new species was the Egyptian Goose (Alopochen aegyptiacus), there were 4 birds. Who knows where this birds come from, probably from somewhere in Europe where they scaped from captivity, or from any public park in a big city...


So, you can see, a really pleasant birthday's birding day!

Monday, January 27, 2014

Cooting

My local patch, l'Aiguamoll de la Bòbila, is the only wetland (apart from the main rivers) in my area. It's the only place where Coots (Fulica atra) bred regularly, and we had more than 20 individuals some years ago.


When the American Mink (Neovison vison) started to invade Catalonia, some individuals reached this wetland and started to breed there. Since then, the population of Coots has fallen drastically. I think numbers are quite obvious:


The thing is that the American Mink is really good preying on Coot's chicks. While the small pullus were on the nest with the adults there was no problem, but since the first day the chicks went out of the nest following their parents, they started to dissapear. In 2011, for example, 5 chicks got out from the nest for first time, and two days after there were just 3. Also, in 2012, I could see just one chick, but probably it had some brothers and sisters that had been eaten before.

I took this (really bad) photos on 2006...
This kind of problems is not always because of 'big troubles' like the America Mink thing. Another factor (not as important,. but still an 'extra factor') has been some fluctuations in the water level. L'Aiguamoll de la Bòbila is a small wetland that receives the water from an aquifer and from the rain, and it's not controlled. This means that strong storms during the breeding season, that usually mean a noticeable increase of water in the wetland, may destroy Coot's nests. Nonetheless, I think that all that +20 Coots that used to be in this place could manage to breed with this thing...


If we look at wintering birds, we are far from that wintering flocks about 10-15 birds before 2007. Actually, during 2013 I saw two birds during the spring, but one dissapeared and some days later, the other too. In September appeared another bird, that stayed until October, but after that, nothing...


... until some days ago, when a bird appeared! I was quite happy for that, and I would have never imagined that the day after, I was gonna catch it!!


In the postjuvenile moult, Eurasian Coots undergo a partial moult that involves most of body feathers, always retaining flight feathers. As you can see in this bird, all primaries, secondaries, tertials, primary coverts and alula are still juvenile, thing that means that it should be aged as EURING 5 (2nd-year).

Also, the orangish tone in tibia (and lack of red) is a good
point for first-cycle birds. Iris colour is quite reddish in this
bird, but with closer views it's possible to see a darker red,
also typical in a 1w.
Following what Cramp et.al. (1979) says about sexing, this bird should be a male. Besides the wing chord, tarsus length, tarsus + middle toe + claw length and bill to feathering on lores are significant measurements to keep in mind.

Monday, January 13, 2014

Good starting!

2014 starts with really nice days. 1st January was full of family events but on 2nd I could ring for first time this year, in my usual place. We had a really pleasand morning, with only 14 birds, but some of them really nice. Actually, last ringing days in December I mainly retrapped some usual birds and I was waiting for a small entrance of some new winter visitors. And they came during 1st January! Some 'new' Song Thrushes (Turdus philomelos), Robins (Erithacus rubecula), Black Redstarts (Phoenicurus ochruros) and this kind of stuff appeared, and I ringed some of them.


Also, a big (I'm talking just about 30...) Meadow Pipit's (Anthus pratensis) flock appeared. And I trapped one bird!! (3 others were perched in the net and 2 escaped from 'inside'... but I'm still happy with just 1 Anthus trapped!):


On the 3rd day, we went to Llobregat Delta. It was a really nice morning, we saw all the typical wintering stuff and also a Common Scoter (Melanitta nigra) and a Red-throated Diver (Gavia stellata) on the beach. Later, in Cal Tet lagoon, I checked carefully the reeds, looking for two Bitterns (Botaurus stellaris) that had been seen lately. Finally, one of them flew briefly, but I could see it preety well! Nice birds to start the year!!
From l'Arana beach
Coots and Cal Tet lagoon.
4th January was a cloudy day, but produced a really nice sighting. The Goosander (Mergus merganser) that had been seen in my area, inland Catalonia, during the end of 2013 reapeared. The bird has only been seen that day this year, between six and half past six in the afternoon. The following day in the morning, it has already dissapeared!

During these days, before exams, I also managed to ring in some roostings. Last year I started a project with a Yellowhammer's roosting, and this winter I continue with it. Bernat and me did a ringing session some days ago, and we trapped 6 new birds.

Photo by Bernat Ferrer
Ring inside the car can be quite confortable!
Also, I've been ringing some Reed Buntings (Emberiza schoeniclus) in other roostings. By this time in the winter, some males start to show a lot of black...


As a consequence, plumage differences in 1w birds, with the abrasion, get more obvious, but some birds can be still a bit tricky. At least, this has an obvious moult limit between tertials and secondaries.


I've already trapped more than 60 schoeniclus this winter in my area, and I trapped a bird with a Spanish ring on December. The greatest surprise was yesterday, when I trapped a Swedish Reed Bunting!


Last year I recovered another schoeniclus during the winter, a bird from Poland. Let's see when it's found one of the birds that I've ringed!