Possible Clues:

• Common garden bird
• Vermin repulsed fish and bird
• Bird watching 'gripping' first of larks
• Flier would be alarming with sort of square in the centre
• Agog about origin of Liver Bird
• Making rude observations about large bird
• Bird with shining body descending on fish
• Outside left looking hard at bird
• Bird looking intently across lake
• Garden bird