Everyone's obsessed with Angry Birds, the most addictive app around. Devotees know all the behaviors of the birds in the game, from the speedy yellow birds to the exploding blackbirds. But what about real-life angry birds? Just what happens when real birds stop being polite and start getting angry? Find out in this funny and informative look at bird anger in the animal kingdom, a collaboration between National Geographic and Angry Birds creator Rovio Entertainment. Fans of the game will love to read these unbelievable stories and the science behind them, alongside fascinating photographs and familiar graphics from the game. The book is organized by degree of nger--Annoyed, Testy, Outraged, and Furious--just as the game progresses in degree of difficulty. Readers are rewarded when the world's angriest real bird is revealed at the end.