skylark \sky"lark`\, n. zool.
   a lark that mounts and sings as it files, especially the
   common species alauda arvensis found in europe and in
   some parts of asia, and celebrated for its melodious song; --
   called also sky laverock. see under lark.
   1913 webster

   note: the australian skylark cincloramphus cantillans is
         a pipit which has the habit of ascending
         perpendicularly like a skylark, but it lacks the song
         of a true lark. the missouri skylark is a pipit
         anthus spraguei of the western united states,
         resembling the skylark in habit and song.
         1913 webster
see also:
alauda arvensis sky laverock lark cincloramphus cantillans anthus spraguei