Here is a description of the game from Spielbox:
Pecking Order was first known as Auf die Palme ("Onto the palm tree" - This is a reference to the German proverb "to bring someone onto the palm tree"). It is a card game by Richard Garfield and George Elias. Two players fight it out with 12 birds of varying values, trying to claim the 10 best feeding locations in the palm of a hand. But since only one bird is allowed at any one space, there's competition. The object of the game is to cleverly place your birds, bluff, and not cheat - even if the engaging theme makes you want to. The player who claims the best feeding spaces is the winner.
From the box:
For 2 players ages 8 and up.