Plover birds are the result of catching NPCs of the same name in southern Sophanem. During the quest Crocodile Tears, 8 plover birds must be given to Crondis. The plover birds given to Crondis during the quest must be captured after receiving the request for them; any birds caught beforehand will be refused, as Crondis claims the player is trying to "trick" her. Plover birds caught before or after the quest currently have no use in the game.
For an exhaustive list of all known sources for this item, see here
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