Monday, 28 January 2013

Asian Desert Warbler

I joined to Yoav Perlman twice to study moult of Asian Desert Warbler at Hameishar Plains in the Negev Desert. This winter is special for this species in Israel with unusually high numbers. The adults perform a complete post-breeding moult on their breeding grounds and juveniles perform partial in the same time. This moult includes normally all GC and varied number of alula, tertials and rectrices. In our second visit, in mid January, we found some individuals starting their pre-breeding partial moult.

Active prebreeding moult

I tried to photo also tails; this is an example of juv. Type tail; R5 on left side replaced, and the different pattern compared to juvenile type feathers is obvious.

This site is very productive for desert species; one of those interesting species was Temminck's Lark. Like all other lark species, Temminck's Larks, adult and juveniles, perform a complete moult after breeding season.

Temminck's Lark

Monday, 21 January 2013

Moult Study

In recent months main I shifted much of my ringing efforts to study moult. My aims are to study and describe moult strategies of the passerines of my region - Middle East and E Mediterranean. Another aim is to shed some light on some ecological questions related to moult. At first I obtained basic moult data for all birds I ringed. Then, my ringing efforts change to more time spent in desert region of Israel to collect data on some interesting and understudied passerine.
One of my target species is Southern Grey Shrike. The first year birds perform an extensive partial moult, most of unmoult the outer secondaries, inner primaries and PC - see this wing:

The extensive partial post-juvenile moult is a typical strategy of short distance migrants or resident species.