From rules: Object of the Game: To develop bird 'nests' (or sets) made up of a Bird card, a Range card for that Bird card, and a Flower card. A nest may also have a Feathered Fact card (for that Bird card) and an Insect card.In order to develop bird nests, each player adds to her/his supply by leading on her/his turn, a card upon which the others will play a card. Usually the lead card will take the trick (a trick is all the cards played, one from each player), but watch out! Every kind of card when led, can be taken by some other card. See the PECKING ORDER. Tricks taken are put in the hand to be used for making nests or for further play. - BoardGameGeek