1 What do we know about predator recognition by untrained birds? -- 1.1 The study of predator recognition (How to make birds respond in etho-ecological experiments - to show that they recognized the predator - nest defense, feeder experiments, laboratory experiments...) -- 1.2 Evidence for predator recognition ability (What predator categories birds recognize - predator vs. non-predator, aerial vs. terrestrial predators, individual predator species...) -- 1.3 Tools used for predator recognition (What cues bird use for predator recognition - sign stimuli, coloration, size...) -- 2 What can the recognition experiments with trained pigeons tell? -- 2.1 Category discrimination and concepts formation (How do birds form categories of predators - memorizing vs. generalization vs. conceptualization...) -- 2.2 Object recognition (What cues birds use for predator recognition - particulate feature theory vs. recognition by components, local vs. global features...) -- 2.3 Other cognitive processes (Are we able to reveal other cognitive processes in predator recognition by birds - amodal completion, priming...).