Blue Tit, Parus caeruleus
One of the most common birds found in British parks and gardens. The Eurasian tits are more colorful analogs to our chickadees.
found the bird below
foraging in blossoms in bloom in freezing cold and snow in the middle
of winter in a fruit tree in a yard on Riversdale Road where we were
staying; this was just to the west of Clissold Park, where I got all
bird photographs of this London visit.
Above and below, Blue Tits in summer; the one above has plumage more worn than the winter birds further up the page; the one below is shown to be a juvenile by gray rather than black dark markings on the head, and the incomplete ring around the neck.