Double trouble: redpolls!

With the current redpoll invasion in Europe, it was time to spend some words and pics on these wonderful birds.

Redpolls all the way from China

Even though it's already been 12 years since we trapped a Mealy Redpoll with a Chinese ring in Meijendel, I stil cherish that moment! Triggered by a recent control of a Chinese ring in Denmark, I made an overview of all European - Chinese recoveries of Mealy Redpolls

Arctic - Mealy Redpoll ID note I wrote a longer note about undertail coverts of Mealy Redpolls. Quite a few males show coverts that no Arctic would be ashamed of! Some are even immaculately white...

#CouessArcticRedpoll #MealyRedpoll #identification

Boxing Day: ageing Black-necked Grebe

25 December. Boxing Day! Rinse and I don't need much time to think when were asked to ring a few birds in bird hospital De Wulp. The star of the day is a Black-necked Grebe.

The poor bird has been bitten in the neck by something, probably a dog. It's recovering fast, but it still needs some time before it can be released. But leave that to the ladies!

Ageing is based on two features. The pale orange iris indicates a young bird; I'd expect a more reddish iris in an adult (see here).

More importantly are the juvenile scapulars, that are obviously still brown instead of black. So yes, this is a young bird (1 cy). Apparently this is only the 14th Black-necked Grebe ever to be ringed in the Netherlands.

It reminded me of the Slavonian Grebe we ringed here back in 2013. Ageing works the same way as in Black-necked. This bird had a red iris, but this was in February - nearly three months later.

There wasn't much contrast in the wing of today's Black-necked:

But brown, juvenile feathers (e.g. the greater coverts) were found in the wing of the Slavonian at the time:

So this too was a 1st winter. I remember it was in great shape: it only got disorientated by lights during the night and therefore ended up at the wrong place (it flew into a building and couldn't get out). It was released straight after the health check: there was no need to keep it inside any longer.

After we ringed the brebe, it became clear only star birds were available, with Guillemot, Razorbill and Kingfisher also ringed. And a lovely Red-throated Loon that frequently uttered a wailing alarm call. Rinse knew this call from the nesting sites in the arctic, but at least it did manage to impress me:

#BlackneckedGrebe #RedthroatedLoon

The look-alike that turned out to be a tristis after all. Maybe. I think so. Right?

Right. Chiffchaffs never stop to amaze me. But I now feel we're really getting somewhere.

Only very recently Peter de Knijff and I wrote something about Siberian Chiffchaff look-alikes on this site. The upper bird in that little web article looked like a tristis, but IMHO it was not an exact copy. Something looked off. So I ringed it as a Common Chiffchaff, without specifying the ssp.

More significant is that it called dozens of times, just before I released it. And it called like a Common Chiffchaff collybita/ abietinus.

The spectogram also shows a perfect match for Common, with an upward inflected call:

I did ask Peter to look carefully at the feather material I collected. Now Peter's mtDNA analyses came in: tristis. Yes, this bird with a hueet call shows tristis mtDNA!

Fairly recently they had a similar case in the UK, see here (scroll a few pics down) and here.

In 2018 Peter and his students will run a second test on all tristis we've trapped at five sites over the past five years. In this second test we'll try to figure out if any introgression with abietinus can be found. This will hopefully give new insights into stray Siberian Chiffchaffs in NW Europe. And in this individual - hopefully!

To be continued!

(I will add this web post as a post scriptum to the afore mentioned web article about look-alikes).

#mtDNA #geneticanalyses #SiberianChiffchaff #CommonChiffchaff #tristi #abietinus