WAnimal cognitionWAlex (parrot)WBeautiful Jim KeyWBird intelligenceWBrain-to-body mass ratioWCat intelligenceWCephalopod intelligenceWClever HansWConsumer demand tests (animals)WDinosaur intelligenceWDog intelligenceWFish intelligenceWThe Genius of BirdsWKanziWLearned pigWWhite-eyed parakeetWGrey parrotWPreference testWPsittacusWTheory of mind in animalsWTool use by animalsWWar pigeonWWhale vocalization