On a mild sunny day when very little was happening, let's look at the four species of tit commonly found in the park. The following four pictures are about the right size relative to each other. Great Tits are the largest, and are amazingly bold, coming down to eat off the hand of people they have never seen before. They have a rather calm temperament, and seldom bother each other.

Blue Tits are a little smaller, and a little more hesitant about coming down. They are more aggressive than Great Tits, spending much time chasing each other about, and aggression and fear go together. However, the same tendency means that they are not dominated by Great Tits, and will knock the larger bird off your hand if it waits there too long.

Coal Tits are tiny; they are the smallest of all tits and the third smallest bird in Europe (after the Goldcrest and Firecrest). They are aggressive towards each other but otherwise very timid, and are pushed around by the larger birds. It takes a long time for one to work up the confidence to come down to your hand, and at present there is only one in the park that will come to me -- it did, this morning, in front of the Rima relief.

All three birds are closely related and used to be in the same genus, Parus. However ornithologists, in their relentless quest to put species into smaller and smaller boxes, have now split them up. The Great Tit remains Parus major, but the Blue Tit has become Cyanistes caeruleus (both names indicate its blueness in Greek and Latin respectively) and the Coal Tit is now Periparus ater.

The Long-Tailed Tit is only distantly related to mainstream tits. It doesn't look much like them, behaves differently, and takes no notice of people at all, being neither frightened nor interested. Except during the breeding season, it is a restless bird, moving endlessly through the trees in flocks, looking for insects.

Its scientific name is Aegithalos caudatus, 'offspring-of-a-goat with a tail', because the northern form of this bird has a pure white head and does indeed look rather like a kid, with its tiny black beak standing in for the kid's nose.

The male Tawny Owl was in his usual place. He was awake when I arrived, and lifted his expressive eyebrows in what I hope was not an expression of pained surprise.

The fact that owls have facial expressions is one of the things that endears them to people.

A Song Thrush on Buck Hill was fading nicely into the scenery with the combination of its dead-leaf-coloured back and counter-coloured, disruptively patterned front.

The quiet colours of a female Shoveller are a relief after the gaudiness of the male.

A Great Crested Grebe was mooching around elegantly in the shade of the willow tree near the bridge.