William J. O’Hearn has been awarded the 2025 Doctoral Prize by the German Primate Center (DPZ) – Leibniz Institute for Primate Research. His doctoral dissertation examines how guinea baboons (Papio papio) assess the foraging abilities of their conspecifics and adapt their social behavior accordingly. The award ceremony will take place on September 10, 2026, at the German Primate Center in Göttingen.
O’Hearn investigated the role that foraging ability plays in mate selection at the Department of Cognitive Ethology at the DPZ. The central question was whether females prefer male baboons who are particularly successful at finding food. To this end, O’Hearn conducted observational studies and behavioral experiments at the DPZ Simenti Field Station in Senegal and at the Nuremberg Zoo.
Tessa Frank The key finding here is that female guinea baboons use social information about a male’s competence to gain access to a food source themselves. When male guinea baboons were taught to open a food box using a lever, they were courted more intensely by their female counterparts. However, if the box was removed—and the “trained specialist” could therefore no longer provide additional food—he lost his appeal again. The animals thus make their social decisions based on outcomes rather than on the fundamental competence of their social partner.
Abteilung Kognitive Ethologie, CRP Simenti Furthermore, O’Hearn was able to clarify the importance of food acquisition for females’ mate selection through his findings: His study documents for the first time that female guinea baboons also hunt prey. Since they are therefore not dependent on their males for meat, they do not choose good “hunters” as mates any more frequently. Here, too, the strategy is results-oriented: Since they can obtain meat even without males, hunting ability is not a factor in mate selection.
“In my PhD thesis, I found that while Guinea baboons can choose social partners based on their foraging, they often do not. In fact, they only use social information about other’s foraging competence when doing so is the best or only path to a particular food source, and even then, they use the simplest possible cognitive processes to achieve their goal.”
Karin Tilch About the Person
William J. O’Hearn studied ecology and evolutionary biology at the University of Connecticut, USA and ethology at the University of Exeter, UK. In 2025, he earned his Ph.D. at the German Primate Center in the Department of Cognitive Ethology under the supervision of Julia Fischer. He completed his dissertation, titled “Social evaluation and partner choice in the tolerant multi-level society of Guinea baboons,” as part of the “Behavior and Cognition (BeCog)” doctoral program at the “Georg-August University School of Science (GAUSS)” at the University of Göttingen, graduating with the highest distinction, summa cum laude. His research has already been published in several internationally recognized journals. The press releases linked at the end of this article provide insights into his work at the DPZ.
Karin Tilch 
Abteilung Kognitive Ethologie, CRP Simenti ![[Translate to Englisch:] A baboon in a dry, leaf-strewn forest holds a spotted bushbuck calf and runs through the undergrowth between thin branches.](/fileadmin/_processed_/6/3/csm_Ein_guter_Fang_99de8efc98.jpg "A good catch")
Lauriane Faraut 
Tessa Frank