Birds will be glad of the thaw, especially smaller ones, and the insect eaters, like Wrens and Goldcrests, which have more surface area to weight and therefore use more energy keeping warm, as do Shrews and other small mammals. Here is an example from a Collared Dove this week, of how birds keep warm by fluffing up their feathers, to trap layers of air which they warm up through their body heat. They also stand one one leg to conserve heat! Conditions: Still, grey day. Snow completely gone here now. Temperature: Max 7 Min 3C.