At the moment, wrens seem to be everywhere. I was in the garden, watching a light smoke of winter gnats simmering in the weak sun, when a small ball of brown feathers darted into the redcurrant bush. The wren scurried through the bush like a mouse, hunting the leafless branches for any sheltering insects.
Insectivores, wrens must check nooks, probe holes, and sift under every lift of bark to secure their elusive sustenance. Severe winters, with insects in ever decreasing supplies, devastate their numbers.