Evidence has emerged suggesting that roosters possess the ability to recognise themselves in a mirror. This discovery challenges the widely-held belief that chickens are limited to basic behaviors such as scraping, clucking, and egg-laying. The findings of this study, conducted by the Universities of Bonn and Bochum, along with the MSH Medical School Hamburg, have the potential to extend beyond roosters and could have implications for other animal species as well. The study, recently published in the prestigious journal PLOS ONE, unveils a new perspective on animal cognition and self-awareness.
The concept of self-recognition and self-awareness has long been a subject of interest in behavioral research. To determine whether animals possess these qualities, scientists often employ the "Mark Test." In this test, a colored mark is applied to an animal's head, which can only be seen in a mirror. If the animal exhibits exploratory behavior towards the marked area on its body while facing the mirror, it suggests that the animal recognizes its reflection as itself. However, the success of this test can vary depending on the experimental conditions, leading researchers to question the impact of environmental factors on self-recognition.
With the aim of creating a more ecologically relevant experiment, researchers at the University of Bonn, led by doctoral student Sonja Hillemacher and Dr. Inga Tiemann, collaborated with Prof. Dr. Dr. h.c. Onur Güntürkün from the Department of Biopsychology at the Ruhr University in Bochum. They devised an innovative mirror test that incorporated a natural behavior of roosters: their ability to emit alarm calls in the presence of predators.
The study involved 58 roosters, each subjected to three repetitions of the experiment. A test arena was set up on the Campus Frankenforst, with a grid separating two compartments where the roosters could see each other. A projection of a bird of prey was displayed on the ceiling of one compartment to elicit alarm calls from the roosters. Remarkably, the roosters emitted 77 alarm calls in the presence of a conspecific and only 17 when they were alone, demonstrating their ability to differentiate between the two scenarios.
Taking the experiment a step further, the researchers replaced the grid with a mirror between the two compartments. The roosters' responses were observed when faced with their mirror image and the projected bird of prey. Over the course of 174 trials, a mere 25 alarm calls were emitted. This indicated that the roosters did not mistake their reflection for a conspecific, suggesting the possibility of self-recognition. However, further investigations are required to conclusively establish this hypothesis.
The research team's innovative approach to the mirror test provides a fresh perspective on self-recognition. By embedding the behavior of the particular species into an ecologically relevant context, the study demonstrates that roosters may exhibit self-recognition when faced with a predator. This finding challenges the conventional understanding of self-awareness in animals and may have broader implications for other species. Moreover, research on self-recognition and self-awareness is crucial in the ongoing discussions surrounding animal rights and welfare.