Possible Clues:

• Everyone, say, backed animal movement
• Quite fast movement of vocal type catching large bird
• Almost all assert aquatic mammal turned up quite quickly
• Singer traps bird by lake fairly quickly
• Singer traps lake bird fairly quickly
• Gretel bowled over and seized by singer at a fairly brisk rate
• Almost assert aquatic beast's return? Not so fast!
• To be played rather briskly (music)
• Everyone, for example, seeing Tarka coming back rather quickly
• Everything, for instance, meeting carnivore retreating fairly speedily