Possible Clues:

• The sort of perch not for fish but for a foul sound
• By the sound of them, purchase for the birds at night
• Sound of purchase of birds
• Stops after flights
• Settlements for birds with places to sleep
• Hen's gathering spots
• Jumpers being passed round -- hush -- they could be what they sleep in
• Places where birds rest
• Places for chickens to rest
• Perches for parrots