Redstarts on the move (some with colour-mutations)

Today's observations:

My day started out with me falling down the stairs of the bird station and lightly stunning a finger on my (thankfully non-dominant) left hand. With my luck for the day seemingly firmly established, as well as initial strong north-western winds, I had very low hopes for the ringing, which I was honestly fine with if it meant I could give my injured finger a bit of rest. During the first few rounds at the Lighthouse garden, I did, however, get decent ammounts of birds considering the few nets I had open, and my finger, though hurting a bit if strained too much, turned out to not be too much trouble and I could handle the birds almost as easily as normal. 

After winds had died a bit down, and more nets had been opened, I started to get some slightly busy rounds, with Common Redtstarts (Phoenicurus phoenicurus) and European Robin (Erithacus rubecula) clearly dominating the numbers. It was down at the non-standard nets at Krattet that I caught the bird of the day: A young male Redstart with a few pure-white feathers on its crown; it was partially leucistic!!

Young male Common Redstart with some pure-white feathers on his crown, revealing him to be partially leucistic. Foto: Alba M. Holmberg

With the ringing spotlight of the day being established as a male Redstart, I might as well demonstrate how we age them. First off, young (1k) males at this time of year generally have very ill-defined black throats, while the adults (2k+) usually have more obvious black throats, even if the black is hidden slightly by white edges to the feathers. But to be completely sure of the ageing, we look at the wing-feathers, particularly the greater coverts. Below is a picture of the same Redstart, showing off his wing-feathers:

Looking at the wing of the Redstart reveals a clear moult-limit in the greater coverts between the inner adult-type gray feathers, and the outer juvenile-type brown feathers. Foto: Alba M. Holmberg

Notice how the innermost greater coverts are edged gray, while the outer ones have dark-brown centres with buff edges. This is because the outer feathers are of juvenile type, which it grew before leaving the nest, while the innermost greater coverts have been replaced by adult-type feathers during the bird's partial post-juvenile moult. Adult Redstarts at this time of year will have undergone a complete post-breeding moult, where they change all of their feathers, so on such a bird, this type of moult-limit would not be found.  

After standard was over, we kept the Station Garden open for a few hours more, and in total, we managed to catch 51 birds throughout the day, distributed over 46 new birds and 5 recaptures. Not a bad day at all.

At the station: Strummer, Alba, Johan