A territorial robin

We seem to have a very territorial robin in the garden, and he, or she, has laid claim to the area around the feeders at the bottom of the garden. Whenever any smaller bid approaches the feeders it is chased away. However, there does seem to be a hierarchy, and the robin only chases away blue tits, great tits or coal tits.

This morning it sat and watched as a nuthatche was feeding. When the male house sparrow visited for breakfast, the robin again sat and watched, but it was very wary, keeping a close eye on the sparrow. The robin can just be seen watching in the photo below.