Possible Clues:

• Goose lay tail up covered by gander's wings, say
• Not the youngest-looking prisoner in bird
• Dreary old convict gets bird
• Breed of goose — Lyra egg (anag)
• Lay egg having flown across river? One might
• See bird lay egg possibly after crossing river
• Wild goose — eg gyral (anag)
• Not certain lass has reared bird