Related Clues:

• Trouble indicator
• Cousin of a crow
• Ominous bird
• Not dozing
• Passerine bird
• Not nodding
• 'Look out below!,' e.g.
• 'Nevermore' sayer
• Awake and aware
• Having pricked ears
• Keen-eyed
• Like watchmen
• Paying attention
• Jet flier
• Like sentries