Possible Clues:

• Bees do it
• Get busy, as a bee
• Sounds as if only one parrot in eight can do what the bees do
• Fertilise (flower)
• Is only one parrot in eight able, by the sound of it, to help with the fertilising?
• Be work for the busy bee
• Sounds as if only one parrot in eight can do what 1 across does
• Fertilize, in a way
• How a bee might cast one vote in eight, by the sound of it, that would help to bear fruit
• Sounds as if only one bird in eight could work like a busy bee