Anesthesia, shots, and twelve dead animals: At the end of July, Nuremberg Zoo euthanized twelve Guinea baboons. The zoo emphasizes that this measure was necessary and is showing results. The remaining group is noticeably calmer. But at what cost? Primate researcher and cognitive scientist Julia Fischer, along with her team, studies the Guinea baboons at Nuremberg Zoo and now offers insights into her research.
The central issue at Nuremberg Zoo was the limited living space. Before the culling, 46 Guinea baboons were housed in a facility that was originally designed for only 25 animals. Fischer explains that confined spaces can lead to tensions and aggressive behavior. Conflicts arise from various triggers, such as competition for food or mates.
In the wild, Guinea baboons from different groups generally avoid each other. Physical aggression is rare, but when it occurs, the animals can seriously injure one another. It is clear: there were confrontations, they were dangerous, and they can likely be attributed to the restricted environment.
Social structures: how baboons live
Guinea baboons organize themselves into reproductive units comprising a male, the "harem holder," one or more females, and their offspring. These units join together to form "cliques," which in turn build a larger social band. According to Fischer, aggressive interactions between different cliques and bands are rare, partly because the animals do not have a pronounced hierarchy. Especially male animals that are related maintain close social relationships. This kinship likely fosters tolerance among them, though unrelated males can also form strong bonds. Females can switch from one male partner to another—at any social level. This flexibility significantly contributes to genetic exchange between populations. Bonds can last a few weeks or several years. The female flexibility and low male aggressiveness are remarkable. The Nuremberg Zoo also states: "For the baboons, regular changes in the social structure are completely natural."
Activists demand castration: "This is a very harsh demand"
The Nuremberg Zoo stated in response to inquiries that a crucial criterion for the decision to euthanize an animal was the absence of a mother-child relationship. For this reason, no young animals were culled. Young animals are particularly important for the social structure, as they promote interaction within the group. Fischer views the demand for sterilization or castration in population management critically: "That is a very tough demand—young animals play a central role in the animals' lives."
The zoo's decision was ultimately the right one, but a long-term concept for managing such groups is needed. According to Fischer, there is little difference between the animals in the zoo and those in the wild. Their social structure is almost identical: "They are Guinea baboons—whether in the zoo or out in the wild." Aside from food intake, the animals spend a lot of time grooming each other's fur. Those who groom each other's fur demonstrate positive affection. Cuddling is also part of their daily routine. This allows researchers to identify which animals have social bonds with each other.
Loss of a partner can trigger stress
The absence of social partners, says Fischer, is "somehow part of their life – even in the wild." Females only join a male as long as it seems beneficial. This can change from one day to the next, especially in the wild where the mortality rate is extremely high.
Immediately after the killing of the twelve animals, the researchers expected the group to react nervously and cautiously. Yet, just one day later, the animals appeared relaxed. "There are bonds – I don't want to deny that," Fischer says. "But at the same time, it's part of these animals' lives that someone is constantly disappearing, being eaten, or migrating. So from their perspective, it shouldn’t be a major catastrophe."
The animals don't miss or suffer – at least not for long. Losing a social partner can cause short-term stress, but usually only for one or two days. "The animals live very much in the moment," Fischer explains. After that, they seek new bonds.
Julia Fischer is a professor of Primate Cognition at the "Georg-August University of Göttingen," head of the "Cognitive Ethology" department, and deputy director of the "German Primate Center – Leibniz Institute for Primate Research." Alongside her research in Senegal, she and her team also study the cognitive foundations of the animals at the "Tiergarten Nürnberg“.