Possible Clues:

• Does a little bird tell you the way to empty it?
• A little bird tells me this is the way to get to empty it, by the sound of it
• Type of bird, may be blue
• It takes only a little bird to empty it
• Small bird — cat finally got the thing
• Common-or-garden bird
• Bird told me to go halves, taking back note
• Bird — and cat beginning to track it
• Singer reversed test, having ultimately scant appeal
• After tango, miss catching heel of cabaret singer