The wren, also known as winter wren or, in dutch, winterkoninkje. At 10cm length it's a LOT smaller than the common house sparrow which we all know as a tiny bird. It's so small and light that I suspect it's the smallest bird of north-west europe.
It's quite easily startled, usually it's a challenge to get closer than 5 meters to wild birds like this.
In this case I was very lucky. This bird followed me for a few meters hopping from branch to branch, chattering at me. It came so close that I could get this shot with my humble Sigma 70-300.