Birds usually move fast and in a three dimensional space, so they must be able to recognize objects they encounter quickly while navigating through their environment. This is definitely true for small birds that become a prey to raptors for which the ability to recognize a predator is a matter of life and death. The ability to recognize and categorize objects have rarely been studied in untrained, wild ranging birds.
Nela Nováková, Petr Veselý and Roman Fuchs at the Department of Zoology, Faculty of Science, have studied four common species of tits that visit the feeders in winter to found out how these birds recognize a predator. The predators were variously modified dummies of the Eurasian sparrowhawk (Accipiter nisus), which the researchers placed near the feeders. Eurasian sparrowhawk is a smaller bird of prey that specializes in hunting small singing birds. The dummies were made as a jigsaw puzzle that could be split into three parts and assembled in various ways. The dummies could have the head placed on top of the trunk (in the normal position), in the middle of the body or at the bottom, in between the talons.
How did the tits respond to these bizarre creatures? The experiment showed, contrary to the expectations, that the birds are equally concerned about all three types of dummies used. It seems that the position of the head does not play a decisive role in recognizing the dummy as a dangerous object. The birds recognize the predator by the presence of the key features (eyes, curved beak), while the spatial position of the body parts is of little importance.
Nováková, N., Veselý, P., & Fuchs, R. (2017). Object categorization by wild ranging birds–winter feeder experiments. Behavioural Processes. https://doi.org/10.1016/j.beproc.2017.08.002