Thursday, April 20, 2017

Spring migration in the Western Mediterranean (I)

This year for Easter I had the great pleasure to participate once again in the spring ringing season in Illa de l'Aire, an small islet south of Menorca, in the Balearic Islands, where the SOM (Menorcan Ornithological Society) has organized the campaign for the last 25 years!! So the first thing I have to write down is a big congrats for all of you, for being such great ringers and very nice friends!

These days' team was composed by Ingela (who got a lot of new-in-hand species!), and Pere Mercadal, a future Menorcan ringer. And of course, the amount of Lilford's Wall Lizards (Podarcis lilfordi lilfordi) that are virtually everywhere in the island!
Islands often hold incredible secrets of evolution of life, as it's the case for instance with the relationship between the Lilford's Wall Lizard and the Dead Horse Arum Lily (Helicodiceros muscivorus). The plant provides juicy fruits for the lizards to eat, that feed mainly on them during summer, and at the same time the seeds get dispersion over the island. The plant is also called "pig's ear" in Catalan for it's shape and texture, and it's full of this 'hair' that trap flies inside. The flower has a characteristic bad smell, for the acumulation of dead flies inside.
Lilford's Wall Lizard population in this island is one of the most dense populations of lizards in the world! And such a density may attract predators, such as Booted Eagles (Aquila pennata), that have learnt to hunt them. And Kestrels (Falco tinnunculus), that might be too keen to visit the island to hunt, and then they are eventually caught on the nets!

The island acts as the very first piece of land that migrants find after the long sea-crossing over the Mediterranean. Even being a rather hostile island, full of pointed rocks and few vegetation, it must look like a great place to spot for them. Some may stay for hours and then jump to Menorca or continue with their travels, other might need several days to have energy to continue, and other might day on the try. Fortunately most of birds apparently succed on their migration journeys.
This Robin was in a rather poor condition, and stayed in the
island for over a week...

Others (such as this Blackcap) will stay shortly, for a day or
just for several hours. Among the few resouces available in
the island, flowers and their nectar are a rather good source
of energy. And also a good pollination for the plants!
We had rather warm and sunny days, almost without wind, and we were lucky enough to have some good migration days. Robins (Erithacus rubecula) were surprisingly the commonest birds, with more than 230 ringed in a single day. Together with several Blackcaps (Sylvia atricapilla)Song Thrushes (Turdus philomelos), Chiffchaffs (Phylloscopus collybita), 1 Meadow Pipit (Anthus pratensis), 2 Dunnocks (Prunella modularis) and 1 Bluethroat (Luscinia svecica) proved the tendency of this year's spring to have some late (mid-April) peaks of presaharan migrants. The two latter species are rather rarely caught in the island in spring!
Meadow Pipit (Anthus pratensis)
Dunnock (Prunella modularis)
Bluethroat (Luscinia svecica)
Willow Warblers (Phylloscopus trochilus) were the second commonest species, and they lead the transaharan migrants passage. Good numbers of Redstarts (Phoenicurus phoenicurus) and still few individuals of species like Pied Flycatcher (Ficedula hypoleuca)Whinchat (Saxicola rubetra)Common Whitethroat (Sylvia communis), Subalpine Warbler (Sylvia cantillans)Nightingale (Luscinia megarhynchos) and Yellow Wagtail (Motacilla flava)Tree Pipits (Anthus trivialis), among other species.
Tree Pipit (Anthus trivialis)
Yellow Wagtail (Motacilla flava)flava subspecies.
Whinchat (Saxicola rubetra)
Whitethroat (Sylvia communis)
Redstart (Phoenicurus phoenicurus)
Common Nightingale (Luscinia megarhynchos)
More interesting transaharan migrants follows:
Wryneck (Jynx torquilla)
Ortolan Bunting (Emberiza hortulana)
Short-toed Lark (Calandrella brachydactyla)
A lot of Hoopoes (Upupa epops)! This season more than 40
 have been ringed already!

Subalpine Warblers (Sylvia cantillans) were caught in few numbers, but with an interesting diversity. We caught up to 4 putative (pending to be accepted by the Spanish Rarities Committee) Eastern Subalpine Warblers (Sylvia cantillans albistriata) and a putative 'Italian' Subalpine Warbler (Sylvia cantillans cantillans). 

4 different Eastern Subalpine Warblers (Sylvia cantillans albistriata), showing tail and
breast patterns. All 2cy (EURING 5). Notice the deep colour restricted to the throat, with
some feathers with white tips. White moustachial stripe wide and well-defined. R5 has a lot
of white, but only when the feather has been replaced!
'Italian' Subalpine Warbler (Sylvia cantillans cantillans), 2cy
(EURING 5) male. The tail pattern is similar to albistriata, with
a lot of white following the racuis on R5. Underparts colouration
has a slightly distinctive deeper area on the throat, with some white
tips, and orangish flanks and belly.
An Iberian Subalpine Warbler (Sylvia cantillans iberiae).
Notice more uniform orangish underparts, and less white
on R5. Some individuals can show white patterns similar
to eastern taxa, and it can even vary in the same individual,
as in this one: usual iberian pattern on one side and a bit
of white following the rachis on the other.
Also 2 males of the recent split Moltoni's Warbler (Sylvia subalpina).
Notice how the breast colour can change drastically in the pictures!,
and it's of course the same bird... In the sun they look quite orangish
(in the picture!!!), but the real colour, salmon-pink, is better shown
in the picture below. Also notice the dark loral area.
Tail pattern of the individual above, with a straight clear cut between
blackish and white in R5, which is likely to be the common pattern
in subalpina.
Two pictures of the second individual, showing the salmon-pink
underparts, a very dark loral area (not always as obvious!), and
very fresh plumage (look at the closed wing in the second picture),
after their usual complete moult in winter.
Talking about Balearic birds, it might be also interesting to show this Balearic Woodchat Shrike (Lanius senator badius).

Adult (EURING 6) female badiusSome females can have a
more similar male-like plumage.
Adult (EURING 6) male.
As you can see, we had a lot of diversity! And Phylloscopus couldn't be an exception:
Phylloscopus species!
from left to right: Common Chiffchaff (P.collybita)Iberian Chiffchaff
(P.ibericus)Willow Warbler (P.trochilus) and Wood Warbler (P.sibilatrix).
Closer picture of the Iberian Chiffchaff...
And a Western Bonelli's Warbler (P.bonelli)!, that was missing
the other day, but was also caught afterwards!
When Sun goes down and Gulls search for a place to stay overnight...

And seabirds, like Scopoli's Shearwaters (Calonectris diomedea) and Storm Petrels (Hydrobates pelagicus), appear around the island, usually delighting with great scenes while they call and display in the dark.

It's also during the night when most of birds caught during the day will continue their travels, and a new bunch of migrants will be brave enough to cross the Mediterranean.

Saturday, April 8, 2017

Local birding days

Since I started birding I've been focusing most of my hours and days in the field close to my place, in Central Catalunya. In practical facts there's an obvious reason to go there, since a relatively proper wetland in less than 10 minutes by foot from my bedroom. And despite you can't compare the place to a true birding hotspot, I have seen quite much interesting stuff and, above all, learnt a lot. These are some lines of experiences in my local areas during some last few days.

I came up with this thoughts the other day when I was extremely pleased watching the first Sandwich Tern (Sterna sandvicensis) seen in my area and in this part of Central Catalunya. Sandwitch Terns are common along the shoreline, fishing in the sea, and they can be seen all year round in the Mediterranean, where they both breed and winter. Nonetheless, inland sightings are very rare! So probably that's why I had never expected this species to show up here. Anyway, the morning of the 25th of March 2017 this individual showed up after an intense storm the previous night.
The whole pale plumage (especially the outer primaries) suggest that it's
an adult (EURING 6 -at least-).
Every spring is different in migration terms! If I had to summarize what this spring season has been so far in my area I would point out the raptors. Due to wind, rain and other meteorological circumstances it has been a remarcable good spring for migrating raptors so far, with no less than 170 Short-toed Eagles (Circaetus gallicus), 2 Booted Eagles (Aquila pennata), 42 Common Buzzards (Buteo buteo), 6 Red Kites (Milvus milvus), 327 Black Kites (Milvus migrans), 46 Marsh Harriers (Circus aeruginosus), Hen Harrier (Circus cyaneus), 35 Sparrowhawks (Accipiter nisus) and 5 Goshawks (Accipiter gentilis). Most of Black Kites were seen together in a big flock the 1st of April in the afternoon, when a Black Stork (Ciconia nigra) decided to pass by too.

Also, White Storks (Ciconia ciconia) flocks have been quite regular. The latest flock spend the night between the 1st and the 2nd of April, and I could manage to see some rings the following morning, mostly from Germany but also 3 from Switzerland, 1 from the Netherlands and 1 from Sweden.

Swedish Stork tiding up...
Some German individuals also wanted to look nice.
While reading the ring numbers I had very good light, which it was a good suport for getting most of the codes. After looking at them for a while, I realised of some plumage differences between individuals. When the information from the ringed individuals comes, it will be interesting to check if this ageing tips are correct!

Second-year (EURING 5). White Storks have a complete
postjuvenile moult, but it starts between December and May of
the second calendar year. This individual, with rather brownish
plumage except for some very fresh (replaced) scapulars, hasn't
started the primary moult yet.
Primary moult suspended probably due to migration. The outer
primaries, primary coverts and secondaries (not replaced) look
more worn and paler than in the individual below. Maybe an a
second-year that hatched rather early? Could a third calendar
year look like this due to earlier complete moult in the second
years? Is it just an adult with more worn old plumage?
Adult, with suspended primary moult, probably due to migration.
Adult, with some secondaries that haven't been replaced (yet)
in the last complete moult.
Most of my ringing stations are making 5 full years of activity this year, and thus some interesting recaps are already possible to get. For instance this (at least) 5 years old Great Tit (Parus major), which was caught with her partner, also ringed the same day and also older than 5 years now!

Blackcaps (Sylvia atricapilla) are probably the most common migrant so far in the area, with rather good numbers.

Also, Willow Warblers (Phylloscopus trochilus)Subalpine Warblers (Sylvia cantillans)Common Redstarts (Phoenicurus phoenicurus) and Nightingales (Luscinia megarhynchos) have arrived, together with an early Pied Flycatcher (Ficedula hypoeluca).
Willow Warbler (Phylloscopus trochilus).
Subalpine Warbler (Sylvia cantillans), male.
Second-year (EURING 5) male Redstart (P. phoenicurus).
Second-year (EURING 5) male Redstart.
Adult (EURING 6) male Redstart.
Common Nightingale (Luscinia megarhynchos).
Adult (EURING 6) male Pied Flycatcher (Ficedula hypoeluca).
This Scops Owl (Otus scops) was also a nice surprise in the nets!

 It was an adult (EUING 6), due to the relatively fresh flight feathers and their pattern, also in the tail.

But local birding also allows to study in proper detail the local species, such as Woodpigeons (Columba palumbus).
Adult (EURING 6). Some secondaries are retained in the last
moult, but they are rather fresh and adult-like (notice for instance
the edges).
Indeterminate age (EURING 4). All secondaries have been
moulted in the last moult, or at least no retained ones are
Probable second-year (EURING 5). Several secondaries have
been retained in the complete postjuvenile moult, they are worn
and narrower
Green Woodpecker (Picus viridis) was a nice bonus for these days, and indeed a species that I don't catch so regularly.
Second-year (EURING 5) female, with all primary coverts still in
juvenile pattern. No red on the malar stripe.
But probably the most local bird I had the chance to study was this Red-legged Partridge (Alectoris rufa) that somehow managed to get caught. A typical second-year (EURING 5), with the two outermost primaries still juvenile.

Let's continue with spring!