The Role of Head and Body Cues in Visual Individual Recognition in Grey Parrots (Psittacus erithacus)
Abstrakt
Individual recognition underlies social behaviors in many species and is essential for complex social interactions commonly occurring between conspecifics. Focusing on visual perception, we explored this process in African grey parrots (Psittacus erithacus) using the matching-to-sample (MTS) method commonly used in primate research.
We used cards made from photographs of familiar conspecific in four consecutive experiments, first testing the ability of our subjects (two male and one female adult) to match the photographs of familiar individuals and then creating modified stimuli cards to determine which visual aspects and features were crucial for successful recognition of a familiar conspecific. All three subjects were able to successfully match different photographs of familiar conspecifics in Experiment 1.
Experiments 2-4 showed that modification of the facial area in the photograph had only a weak effect on subjects' success rates in MTS tasks. On the other hand, changes in the plumage color or obscuring of abdominal cues impaired their ability to successfully match conspecifics' photographs in some tasks.
This study implies that African grey parrots process visual information holistically. Moreover, the process of individual recognition in this species differs from what we find in primates, including humans, where faces play a crucial role.