Back from the steppe: Iduna-warblers

After three months of fieldwork and birding in the vast country of Kazakhstan, time to edit all the recordings and share the interesting ones. We've had a wonderful time with excellent birding, especially in the Kazakh Altai. One of my main targets in understanding bird sounds for this trip was to see whether the calls of Booted Warblers (Iduna caligata) and Sykes’s Warblers (Iduna rama) differ from each other. Of course this must have been written somewhere, but you learn more from it when you discover it yourselves. I tried to record as much ‘Iduna’-warblers as possible, but those warblers call very softly, often in short phrases and wind was always present. Therefore, not much recordings, but enough to have a clue.

First of all, all recordings are made of birds which I identified myself on plumage and song. I think that the difference in call is actually not difficult to hear, but much more difficult to see and show on a sonogram. In simple words, Booted has a somewhat smacking ‘chack’-call, reminiscent of Stonechats, while Sykes’s Warblers have a harsher ‘tak’, or even ‘tok’-call, more like a soft Blackcap or Lesser Whitethroat. Of course my sample size in recordings is low, but in the field the difference was also audible and I didn't notice much variation within and between individuals.

Let’s hear!

Booted Warbler:

Sykes's Warbler

More recordings can be found on Xeno-Canto: Booted & Sykes's