Posts tonen met het label tristis. Alle posts tonen
Posts tonen met het label tristis. Alle posts tonen

donderdag 1 december 2011

Sonograms - no rise or fall in pitch

Herman van der Meer kindly provided this sonogram of the soundrecording by Theo Muusse. Theo recorded several calls of the tristis, either did Jaap Dijkhuizen. I am grateful to this help of my friends! Accepting this record by the CDNA will be peanuts now.

Sonogram recording 29/11 - Theo Muusse/Herman van der Meer
The sonogram shows clearly the typical, sonore 'chickencall': 'whee'. Note that the flat line bows a bit down a the end of the calls. But 'no rise or fall in pitch', as Mark Constantine would say.

Recording Theo Muusse With in the background a Water Rail. Recorded with a Sony LS10. Nice device!

More about the calls of Siberian Chiffchaff: Mark Constantine & The Sound Approach 2006: p. 27, 90 and 105.

donderdag 24 november 2011

Tristis - Siberian guest on local patch

This afternoon I decided to check the polders of the Biesbosch, a sort of a local patch for years. After the regular sightings of Tundra Beans, Hen Harriers and White Egrets, I got a walk to the observation shack of polder Maltha. 

About hundred meters before the shack, I noticed a strange call, resembling the first part of the call of a Siskin. But after a quick walk on the dike, it seemed clear to me: a continuously calling Siberian Chiffchaff, say tristis! The bird was foraging in some small shrubs, while calling the typical 'whiee', whithout any variation. Observing the plumage, it turned out to be a classical greyish bird, with black legs, buff-brownish cheeks et cetera. Here some pics.

tristis - Brabantse Biesbosch,  polder Maltha, 24/11/2011
tristis - Brabantse Biesbosch,  polder Maltha, 24/11/2011  Note the paler cutting edge of the bill.
tristis - Brabantse Biesbosch,  polder Maltha, 24/11/2011

tristis - Brabantse Biesbosch,  polder Maltha, 24/11/2011
Almost exactly one year ago, my friend Peter Verhelst and I found a tristis near Maastricht. That bird had the same plumage and call and also disappeared after some minutes. Either leaving us without a voicerecording. It is still circulating in the second round of the CDNA. I think the commission won't accept sightings whithout a good voicerecording because some Dutch papers about the variability of tristis stress the importance of their voice.

tristis - Maastrich, Pieterplas, 23/11/2010 (Peter Verhelst)