Possible Clues:

• Eat a bird of passage
• Buy polish off singer who’s often high
• Bird needing second mudbath?
• 'It'll get down its throat, swift-like (7)'
• Bird's down
• Permit given to Cornish flyer?
• Get the bird down and let it come to and end
• Would you believe it; a bird!
• No down on the bird, just get it down
• Eat like a bird