a bob, bob, bobbin along

I waited in the garden today for about an hour or so to get a photograph of the robin and eventually he showed up for his meal worm lunch.
Landing in a bay tree possibly 3 metres from me with a temperature approaching -7 degrees I took a few shots of the robin (there were actually three) and a number of thrushes, starlings etc.
How do they cope with the cold as I was shaking so much I think the photograph may be slightly blurred as I don't have IS on this lens.
Hope you like it anyways.

Canon EOS 40D with Canon 70-200 F4L. 1/160 sec ~ F4.0 ~ ISO 200 ~ pattern metering.

Processed through CS5 - boosted contrast, vibrance and reduced size to 800 pixels on longest edge. Sharpened using unsharp mask set at ~ amount - 150% ~ radius 0.3 pixels ~ threshold 0.