Hatching tickets can be used in the hatchery building to obtain birds. You can earn the tickets in the game as rewards from events and battles. Please remember there are three types of hatching tickets, and have different effects when hatching birds. Note that a totem may be also be obtained instead of a bird during a hatch.

Bronze ticket – You can earn birds with star rating from 1 to 3 by using those tickets.
Silver ticket – Birds with star rating from 2 to 5 can be obtained with those tickets, however, a silver ticket does not guarantee that a 4 or 5 star bird will hatch each time.

IMPORTANT: Using ten silver tickets simultaneously does not guarantee a 4 star bird.

Gold ticket – By using this ticket, you can hatch birds with star rarity from 2 to 5 just like silver ticket; however, a single hatch will provide ten hatches in a single attempt with at least a single 4-star bird being guaranteed to drop.