'God put a smile upon my face'

In the night of 11-12 June, a midnight 'piepje' (message) announced a calling Little Crake (Porzana parva) in the Weerribben in Overijssel. During the afternoon a plan was made to go for the bird in the evening as we never heard it before and because Alwin is quite busy with a big year. In the meantime, another Western Bonelli's Warbler (Phylloscopus bonelli) was discovered near Arnhem. It's a rather good species for June. The plans were changed last minute once again. Toy picked me up to go for the warbler and we eventually would meet Alwin and Joep somewhere for carpooling.
The Bonelli's Warbler wasn't that difficult to find and identify. Short strophes and an nice 'v' instead of a '^' (checked beforehand on recordings ;) ). When it started calling it became even more easy. I was quite happy with recording the call, didn't hear the last one calling and during my first one I didn't have a recorder yet (I was so jealous of Sander Bot and decided to buy one myself). So a first recording for me!


And of course a recording of the song. Note the second strophe: it shortly introduces the song by calling.


In the meantime it became clear that Alwin was having a diner, so we would meet him at the Crake. We arrived at 21:45 and when walking to the spot, we already got some 'got him' messages! From quite a distance we heard the bird calling. Apparently, my microphone made an impression and immediately the group became silent when I started recording. According Pieter Doorn, my face was priceless when the bird started calling and continued in singing. A big smile appeared on my face, what an amazing sound! Among nocturnal birdsounds, this is absolutely 1 or 2 of the list, competing with Thrush Nightingale.
Note the change in call type when the bird is proceeding into singing:


I made a short walk along the cycle track and heard Common Pochards (Aythya ferina) calling. Never heard it this clear and consious. However, the calls were really weak, so the recording is not that good.


By the way: thanks for all the nice (personal) comments on recordings, I really appreciate that :)
  

Western Bonelli's Warbler

This morning a Bonelli's Warbler was discovered near Arnhem in Westervoort. As I never heard a Bonelli's Warbler (Western nor Eastern) singing, I was eager to go for the bird. The song and the call of the two species of Bonelli's Warbler differ from each other, so this would make it interesting for soundrecording.

First some recordings:

A long recording with 4 trillers.


A recording with 1 triller. And here the corresponding sonogram:

 







And a recording of 1 trill which was slightly different from the other ones. I only heard it once. And also its corresponding sonogram:

Now, the identification of the species. I would like to refer to the (excellent) article of Dick Groenendijk and Teus Luijendijk (Dutchbirding 33: 1-9, 2011). They give a table of key parameters which distinguish the two species. The first parameter is the shape of one note. An upright 'V' for Western and an inverted v or '^' for Eastern, here obviously an upright 'V'. The second parameter is the last part of one note of the trill. This should be a / in Western and a \ in Eastern. Also this points to Western. The maximum frequency is 7200 Hz for Western and 6300 Hz for Eastern. In my recordings I come at an average of 7000 Hz (n=18), so again Western. I guess the ID is already known, but we will check the last two parameters. The average numbers of notes per trill in this bird is 10 (+/- 1). For Western this would be 9 (+/- 2) and for Eastern 15 (+/- 4). The lenght of the trill is 0.53-1.24s in Western and 0.71-1.70s in Eastern, in our bird this is 0.657-0.812.

Awesome birds, and I am really happy that I saw and heard the bird. To bad it didn't call, but now we could use the referred article in practice ;)