Arctic warbler split

As a Portuguese birdwatcher, Arctic warbler has been, for a long time, a most wanted bird and one of the rarities that one wishes to tick.
So far there’s only one accepted record in Portugal. In 2009 (September 28) a juvenile was ringed in Santo André lagoon  by Carlos Pacheco and others (see here).

This species winters primarily in Malaysia, Phillipines and Indonesia.

I’m currently in Java, and the opportunity to observe and study Arctic Warblers in the wintering grounds seems irresistible.

But here arises a problem…

Arctic Warbler has now been split into three cryptic species due to differences in genetics.

Extracted from the paper “The Arctic Warbler Phylloscopus borealis– three anciently separated cryptic species revealed”
Extracted from the paper “The Arctic Warbler Phylloscopus borealis– three anciently separated cryptic species revealed”

The split was proposed in 2011 in the following paper: “Alström, P., Saitoh, T., Williams, D., Nishiumi, I., Shigeta, Y., Ueda, K., Irestedt, M., Björklund, M., and Olson, U. (2011). The Arctic Warbler Phylloscopus borealis– three anciently separated cryptic species revealed. Ibis 1532: 395–410”, an abstract of which can be seen here and here.

According to this paper distinguish these three species will be impossible by plumage alone, leaving us with calls and songs as the only safe method of ID.
On February 7, 2015 in Bogor Botanical Garden  a warbler caught the attention.

Plumage and structure seemed to be typical of Arctic warbler, although much greyish in tone than a previous bird seen at the same place, identified as Phylloscopus borealis (photo here). But as we already know plumage is of little use in the field.

Fortunately it was calling and I managed to get this recording:

http://www.xeno-canto.org/212895/embed?simple=1

The double note call seems to indicate Phylloscopus examinandus. Looking at the sonogram we can see two syllables:

Sonograma examinandus

If we compare to the example in the previous paper we can see similarities:

Extracted from the paper “The Arctic Warbler Phylloscopus borealis– three anciently separated cryptic species revealed”
Extracted from the paper “The Arctic Warbler Phylloscopus borealis– three anciently separated cryptic species revealed”

On March 18, 2015 an Arctic warbler Phylloscopus borealis was recorded at the same place. It was much silent than the previous bird. Only calling randomly, a single note call:

http://www.xeno-canto.org/229193/embed?simple=1

The sonogram shows one sillable:

Sonograma borealis18_3

Comparing with the sonogram in the paper we can see the same pattern:

Extracted from the paper “The Arctic Warbler Phylloscopus borealis– three anciently separated cryptic species revealed”
Extracted from the paper “The Arctic Warbler Phylloscopus borealis– three anciently separated cryptic species revealed”

Today I managed to record another Arctic warbler P. borealis, a single note call given when I approached the bird:

http://www.xeno-canto.org/233578/embed?simple=1

The sonogram:

Sonograma borealis30_3

I would like to hear some inputs on these observations, especially on the recording of P. examinandus.

Raptors at Pangrango

Last saturday I went to  Gunung Gede Pangrango National Park with my birding companion, Tri Susanti.

IMG_3917

After a hiking of 3 hours (to many birds to discover!) we reached the Swamp (a forest clearing with head-high grass and a well known place in here).

Soon as we arrived we detect an adult Crested Serpent-eagle Spilornis cheela soaring.

Then displayed in flight (diving followed by an ascent flight with raised wings, beating them for a few seconds in that position, performed a few times).

femeadisplay

We were still talking about this behaviour when a male Javan Hawk-eagle Nisaetus bartelsi (we weren’t able to tell the age of this bird), also started to display above (diving followed by an ascent flight and then gliding, also a few times).

machodispaly2

machodisplay

After that a juvenile male Javan Hawk-eagle was seen interacting with an adult female, disappearing behind the canopy.

young_femaleTo end a Spotted Kestrel Falco moluccensis flew overhead with a small lizard as prey…

moluccensisI know, crappy pictures! Very light sky and impossible to get better… but you get the idea.

(E-bird list here)

Travel Draw Bird…ing!

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