Dunnock Prunella modularis, Accenteur mouchet.
3 occurrences (1 hedge-sparrow, 1 sparrow, 1 sparrows')
1H4 5 1 61 Useth the sparrow - did oppress our nest,
LR 1 4 213 The hedge-sparrow fed the cuckoo so long,
LUC 849 Or hateful cuckoos hatch in sparrows' nests?
It is surprising to find this very unobtrusive and drab bird mentioned by Shakespeare, on the other hand it is recorded by ornithologists as a regular and frequent host to the cuckoo.
If animal metaphors are important in King Lear, the theme of ingratitude of children towards their parents can also be seen in birds, such as the "pelican daughters" or the hedge-sparrow that
fed the cuckoo so long,
That it's had it head bit off by it young. [sic]
(1 4 213-4)
This saying finds its root in the fact that there is very quickly a great difference between the size of a young cuckoo and that of it's foster parent. The head of any of those small passerines disappears into the wide gap of the wide-open bill of the voracious cuckoo, and one wonders if the little bird is going to be eaten as well. In fact some of them have their heads worn bald by repeatedly thrusting their head into the beak of the cuckoo in order to feed it.
Again we are faced with a striking image evoking both parricide and cannibalism (see PELICAN) which participates in the more general theme of monstrosity that runs throughout King Lear.