Killing Surplus Animals Is Not Conservation

Zoos Cannot Replicate Natural Social Structures

Geladas are highly social primates that commonly live in complex, multi-level societies in the Ethiopian highlands, where small reproductive units form larger bands that may include dozens or even hundreds of individuals. The artificial constraints of captivity make it impossible to replicate their natural social structures, and tensions within captive groups are frequently cited by zoos as a justification for interventions.

A Structural Problem in Zoo Breeding Programs

However, the recent killings were not the result of a sudden emergency but of a planned population management decision. Such practices are linked to the way coordinated breeding programs operate in many zoos. Encouraging animals to reproduce even when their long-term living space is limited, which inevitably leads to certain individuals being classified as “surplus”.

Zurich zoo managers underline that animals must reproduce to enhance their welfare; however, there is no scientific evidence to support this contention. Animal welfare science focuses primarily on physical and mental states: overall health, stress levels, comfort and the ability to express species-specific important fundamental behaviours. Preventing reproduction does not in itself compromise welfare, and population management tools such as contraception or controlled breeding are widely used in both wildlife management and zoological settings.

In this specific case, most of the animals killed were very young individuals. The euthanasia of healthy animals – including juveniles – undoubtedly causes emotional stress among the survivors, raises serious ethical questions and highlights a structural issue in the way captive populations are managed. “This practice not only violates ethical principles but likely contravenes Swiss animal welfare law, which protects the dignity of every individual animal”, explains Anna Zangger, lawyer and head of International campaigns at FFW.

It’s interesting to note that while the Zurich Zoo has sought to justify the killing of these primates by citing EEP (Ex Situ Programme) best-practice guidelines, these very guidelines do not recommend culling as a routine first response. Section M of the EEP guidelines details alternative population-management approaches, including contraception, vasectomy and management of surplus males. These guidelines explicitly state that culling may be considered only after alternative solutions have been fully evaluated under the EAZA (European Association of Zoos and Aquariums) Culling Statement. On that basis, responsibility appears to lie primarily with the zoo’s own long-term management decisions: the gelada group was reportedly allowed to grow to 48 individuals, and healthy animals were subsequently killed when space and transfer options were no longer available.

The Limits of the “Conservation Zoo” Narrative

Zoos often present themselves as institutions dedicated to nature conservation. However, in most zoological institutions worldwide, the primary focus remains on the exhibition of animals for public entertainment, while conservation budget represents only a small fraction of their overall revenues. The few zoos that do contribute significantly to conservation achieve their greatest impacts by acting directly in the natural and wild habitats of threatened species, and – unlike Zoo Zurich – do not feel the need to keep those species captive in their unnatural entertainment displays.

“In the case of geladas, this model is particularly difficult to understand as they are not threatened with extinction, remaining listed as Least Concern on the IUCN* Red List. Furthermore, there is no documented record of zoo-bred geladas being released back into the wild. Breeding animals into captivity only to later eliminate them as ‘surplus’ is not conservation — it is zoo population control”, according to Tomas Sciolla, Biodiversity Conservation and Zoo Transformation Specialist, Fondation Franz Weber

For Fondation Franz Weber, the deaths of the ten geladas raise broader questions about the role zoos play and whether breeding animals in captivity – while regularly eliminating individuals deemed surplus – can genuinely be described as a conservation effort.

*International Union for Conservation of Nature