1.  birdcall(n = noun.communication) birdsong, call, song - the characteristic sound produced by a bird; "a bird will not learn its song unless it hears it at an early age"
is a kind of animal communication
has particulars: bell-like call, two-note call

2.  birdcall(n = noun.artifact) - a device for imitating a birdcall;
is a kind of acoustic device

1.  A sound made in imitation of the note or cry of a bird for the purpose of decoying the bird or its mate. [1913 Webster]

2.  An instrument of any kind, as a whistle, used in making the sound of a birdcall. [1913 Webster]