THE NORTH RIDING PROJECT

The black lark (Melanocorypha yeltoniensis) is a large, robust lark, 18-20.5cm in length.  The bird is of the open steppe of south-eastern Russia and Kazakhstan, and is a very rare vagrant away from its breeding area.  The adult male is unmistakeable, being all black with some pale feather fringes on its back, and with a yellowish or pink bill.  The female is undistinguished in comparison, mainly dark-blotched grey above and paler below.  Her legs and underwing are black.  The song is like a frantic version of that of the Eurasian skylark. 

Wikipedia

There have been two official sightings of the black lark in Britain: at Spurn in 1984, and at South Stack, Anglesey in 2003.  Among a number of unsubstantiated earlier recordings, Arthur G. Butler claims in his Birds of Great Britain and Ireland that “a flock of this species visited the south-east of England in January, 1907”, proposing that the birds escaped from crates being carried over the sea for sale at Leadenhall Market.

see Butler/Birds, 1907