Possible Clues:

• They fly for flies and does this to them
• Reluctantly accepts adequate criterion for summer being here?
• Birds one eats as one may roll around in the ship
• Strange slow laws apply to birds
• The migrants get the pigs around the wall
• Believes there's flounder on board
• All up in the air, but one gets it down
• Book by Arthur Ransome
• They eat flies as they fly
• Birds splash around in far side of Ness