Eurasian Blackbird, Turdus merula

Eurasian Blackbird, male, 12/26/09, Clissold Park, London, UK

The Eurasian Blackbird is a thrush of the genus Turdus, and so a cousin of the American Robin. It is not closely related to the North American blackbirds, which belong with orioles and meadowlarks in the Icteridae family.
 
Eurasian Blackbird, female, 12/28/09, Clissold Park, London, UK

Eurasian Blackbird, male, 5/6/11, Regent's Park, London

Eurasian Blackbird

Eurasian Blackbird, juvenile, 5/6/11, Regent's Park, London

Eurasian Blackbirds
An adult male Blackbird completes the handoff of an item to its fledgling, the last image in an sequence, the whole of which can be seen here.  The item is most likely a food item prepared by the adult, something like a mashed-up earthworm; other possibilities are noted at the linked site.