The First Winter Blackcap in the Garden...or is it a Late Migrant?

I spent the day at home today and so had the chance to put a net up in the garden. The usual suspects were present, blue tit, great tit, coal tit and great spotted woodpecker, but also a couple of marsh tits. Marsh tits are regular visitors to my garden in the winter and over the last 12 years I have ringed nine new birds in my garden. I did not have my binoculars handy and therefore could not see whether these birds had been ringed before, but I will keep an eye out. 

A steady trickle of blue tits were passing through the garden, when a juvenile male blackcap turned up in the net. I had glimpsed a male blackcap earlier in the day in another part of the estate and suspect that this is the same bird.

Juvenile Male Blackcap

This bird was in immaculate condition, the wing and tail feathers were very fresh and it was in good condition, having a fat score of 1 and a muscle score of 2.

Juvenile Male Blackcap

My immediate impression was that this bird was a winter visitor that had just arrived, but given that there is still a scattering of migrants present in the UK, such as subalpine warbler in Cornwall, a few dusky warblers and chiffchaffs, it could just be a late summer migrant. The next few months will determine that..