The wellbeing of undesired animals in zoos and aquariums

Compassionate zoo grounds for everyone: Care and regard for undesired animals

Written by Sabrina Brando and Max Norman

Who are undesired animals?

Zoos and aquariums are not only home to a myriad of species in human care, but also to a multitude of free-living wildlife species that call the facility grounds their home. Animal care facilities, thus, face the complex challenge of managing these so-termed ‘undesirable’ species that are not deliberately housed. These so-called "pest" species can include rodents, bird and insect populations that have the potential to damage property and infrastructure, spread disease, compromise animal wellbeing through injury, illness, or resource competition, and they may also pose risks to visitor and staff safety. Nonetheless, they have become reliant on our facilities as places of shelter, as a food source, and safe places from predation and other pressures of the outside world.

Compassion for all beings

While undesirable, these animals have an inherent right to life and compassionate treatment just as the animals in our care do. Facilities should, therefore, be considering the wellbeing of undesired individuals and species along with their priorities of the safety and wellbeing of the animals, employees, and visitors within their direct care.

Where the wellbeing of undesirable animals is not in conflict with the health and safety of the animals we choose to care for or the people we have care responsibilities for, ways of coexisting should be promoted. Providing alternative options for homes and feeding areas, such as wild areas on-site, or integrating the presence of smaller birds in outdoor habitats into educational interpretation are some options zoos have chosen to pursue. On-site wildlife reserves, bat boxes, bird hides, insect hotels, feeders, and other options can allow us to live peacefully alongside wildlife by directing them to safe places to look after themselves.  

Strategies for undesirable animal management

Where there are conflicts, greater efforts to protect the animals we care for and ourselves in a way that minimises the negative impacts on wildlife and undesired species should be taken. Zoos and aquariums should look to employ an integrated approach using multiple ethical and compassionate techniques in combination. Lethal methods are often used, which can vary in how ethical and humane they are in practice; for example, while certain types of snap traps are largely effective at instantly killing an undesired rodent (though not at 100%), glue traps are not and directly cause prolonged suffering. As organisations dedicated to the wellbeing of animals in our care and in the wild, the compassion we have for animals should extend to even those animals we would rather not have on our grounds for health, safety, or other reasons.

Non-lethal methods that permit peaceful and non-harmful coexistence of humans, the animals in our care, and wildlife are available and emerging technologies as well as traditional methods can be effective strategies. Habitat modification through exclusion and proofing is widely used to prevent undesirable animals from entering areas where they may present risks, while trapping and relocation remains more common for mammalian species. Limiting food waste and effective waste management should remain priorities to limit the attractiveness of habitats and other areas to undesirable animals. Reducing reproduction through contraceptive baits and other emerging technologies are on the rise, as are Trap, Neuter, Release (TNR) programs for larger mammalian species. Where lethal control is used, thorough assessments should be conducted that the methods used are the most compassionate and ethical available and have considered the environmental impacts such as the cumulative effect of toxins in the food chain and pollution of soil and water.

Ways forward

As animal wellbeing philosophies continue to prioritise an ethical and compassionate approach for all species, zoos and aquariums should prioritise exploring new tools, including for non-lethal undesired animal population management. A growing emphasis on coexistence aims to reduce conflicts through prevention over reactive and lethal measures. Ongoing assessment of best practices will help facilities sustainably and compassionately balance the interests of all animals inside and outside of their direct care.

Presently, there is a need for increased guidance that considers and balances the multiple deliberations for ethical management of undesirable populations of free-living animals over human interests and deliberately housed animals wherever possible, with philosophies of compassionate and ethical management that prioritise the wellbeing and experiences of all animals, regardless of how they are perceived by humans.

As organisations concerned with the wellbeing of animals, greater attention to the wildlife we inadvertently or deliberately impact through our actions is of just as much importance as the wellbeing of the people and animals we care for. Aligning our ethos with our actions and ‘walking the talk’ will bolster our roles and reputation as places that put the wellbeing and conservation of animals and habitats at the forefront - starting with our habitats at home.

Research & survey

This blog is part of ongoing research and writings in the space of undesired animals in zoos and aquariums. We would be interested and grateful to hear how your organisation, or as individual, are approaching undesired animals. If you have examples of for example a trap and release program, keeping rodents alive and relocating them, or providing alternative options for homes and feeding areas, such as wild areas on-site as mentioned in the blog, please reach out to us, we would like to learn more of what is working already.

We would be grateful if you & your organisation would participate in our short survey on undesired animals. You can do so by clicking HERE