One Health, One Welfare: A Unifying Framework for Zoos

Zoos and aquariums (hereafter ‘zoos’) bring together expertise in conservation, animal care, and connecting people with nature. However, a historical challenge for zoos is how to build programs that connect these strengths, which are often siloed. One Health, One Welfare (OHOW) is an interdisciplinary approach that promotes the shared health and wellbeing of people, animals, and the environments we share. We argue that OHOW can serve as a unifying framework to support zoo missions. Additionally, we illustrate that zoos are uniquely positioned to play a leading role in OHOW initiatives including protecting wildlife, public health, and ecosystems around the world.

Zoos and aquariums (hereafter ‘zoos’) bring together expertise in conservation, animal care, and connecting people with nature. A challenge for zoos is how to build programs that connect these strengths, which are often siloed. Different teams are usually involved in animal care, in situ conservation, and public engagement. The concepts of One Health [1] and One Welfare, [2] collectively termed One Health, One Welfare (OHOW), can unify animal care, conservation, and public engagement under a holistic approach to animal and human wellbeing for which accredited zoos are uniquely positioned to play a leading role (Figure 1).

One Health is an interdisciplinary framework to improve health outcomes by acknowledging and examining the interdependence of human, animal, and environmental health [1]. However, good health is only one component of positive animal welfare [3], which is a core priority for accredited zoos [4]. The One Welfare framework expands the One Health perspective by explicitly advancing animal welfare (i.e., an animal’s quality of life)[5] in relationship with human wellbeing and environmental conservation [2]. Collectively, OHOW is an interdisciplinary approach that promotes the shared health and wellbeing of people, animals, and the environments we share. Here, we seek to broaden awareness of how One Welfare complements and expands upon One Health to position zoos as leaders in OHOW initiatives.

The OHOW framework encourages zoos to integrate perspectives on conservation and human wellbeing into an animal welfare focused care program. Under this framework, positive animal welfare is paramount, providing the ethical foundation and social license that enable zoos to fulfill their mission, including in situ and ex situ conservation efforts and initiatives to connect people to nature. Behavioral research conducted in situ can inform zoo animal management, while ex situ research can guide field handling and conservation efforts [6,7], highlighting the interconnected and reciprocal value of a holistic OHOW framework in supporting zoo missions.

The OHOW framework introduces considerations for animals involved in educational programming. While these animals often play an important role in conservation education and public engagement, a OHOW approach requires that their participation be guided by clearly articulated welfare objectives alongside institutional learning and engagement goals. This includes the appropriate selection of animals for these roles. For example, under a OHOW framework, nocturnal species would not participate in daytime programming, as this conflicts with their natural history and is likely to compromise health and welfare [8,9]. Historically, educational programming has presented animals in highly artificial contexts, which may negatively affect welfare and misses valuable opportunities to educate the public about natural ecosystems. OHOW encourages the development of integrative educational programs that prioritize animal welfare [10,11], enhance understanding of natural history, and promote engagement with conservation and environmental sustainability initiatives.

OHOW can also extend to live animals used as feed within zoos (e.g., mealworms), an often-overlooked component of institutional welfare responsibility [12]. Applying OHOW principles requires that feeder animals be sourced from vendors meeting institutional health and welfare standards and feeder animal husbandry should align with each species’ natural history and promote colony health by minimizing stress. Incorporating feeder animals within a OHOW framework can benefit animal nutrition [13] and strengthen institutional credibility in animal welfare advocacy.

The OHOW framework also challenges zoos to consider the health and welfare of all living things, even species that we must control because they are invasive or potentially harmful. For example, free-living animals (e.g., commensal rodents) may be attracted to resources on zoo grounds, but can transmit pathogens to zoo animals or cause property damage. Under the OHOW framework, methods to control unwanted animals would minimize pain and suffering, as well as unintended impacts on the broader ecosystem. Integrated pest management approaches that emphasize prevention, environmental modification, and avoid pesticides reflect a holistic OHOW approach [14,15].

Zoos can contribute meaningfully to human wellbeing by fostering connections to nature [16], supporting staff wellbeing [17], engaging visitors [18], and strengthening connections within broader communities [19]. These outcomes are mutually reinforcing, as positive perceptions of animals are closely tied to high standards of animal welfare [20,21], which impact staff and visitor experiences and wellbeing [17,22]. In turn, this positive feedback loop between animal welfare and human wellbeing may also influence human behavior toward sustainability and conservation initiatives [23].

For zoo staff, OHOW emphasizes the value and meaning derived from caring for animals. Animal care professionals often report strong emotional connections to the animals they manage, and this sense of purpose can enhance job satisfaction [17]. A OHOW approach recognizes that staff wellbeing is central to animal welfare outcomes. When staff are supported through adequate training, manageable workloads, institutional recognition, and health and wellness resources, they are better positioned to provide high-quality, compassionate care. Conversely, caregiver burnout and compassion fatigue [24] can negatively affect both staff wellbeing and animal welfare [25], which may lead to negative visitor perceptions and limit an institution’s capacity to engage audiences in conservation initiatives. OHOW therefore underscores the importance of institutional cultures that prioritize staff support as a means of sustaining positive welfare for animals and advancing conservation.

For many visitors, zoos provide accessible opportunities to connect with nature, particularly in increasingly urbanized communities. These experiences can support emotional wellbeing by eliciting positive feelings such as joy and relaxation [26]. Importantly, research suggests that observing animals engaged in species-typical behaviors and appearing healthy and active, enhances visitor satisfaction and perceptions of zoos as ethical institutions [22]. Additionally, zoos play a critical role in public education about biodiversity conservation. Through interpretive programming and educational exhibits, zoos can increase awareness of global conservation challenges and empower visitors to engage in pro-environmental behaviors.

Zoos can further advance the health and wellbeing of people by fostering connections to local wildlife and ecosystems. Many zoos have outreach programs that both teach and reciprocally learn from community members about local biodiversity and conservation challenges. Initiatives such as community science programs, habitat restoration projects, and community gardens, can strengthen the environmental stewardship of community members, promote community cohesion, and benefit local biodiversity. Community members involved in conservation initiatives report benefits to their physical, psychological, spiritual, and social health and wellbeing [27,28]. OHOW illustrates that by supporting staff, enriching visitor experiences, and engaging local communities, zoos can create positive feedback loops in which animal welfare, human wellbeing, and environmental stewardship are reciprocally strengthened.

Another important pillar to the mission of modern, accredited zoos is the conservation of wildlife populations. Although zoos are uniquely positioned to advance ex situ conservation such as managed breeding programs, many zoos contribute to in situ conservation [29], for example through monitoring and reintroduction programs [30,31]. The OHOW framework can help align in situ and ex situ conservation efforts to improve the health and wellbeing of wildlife and their habitats. For example, zoos support reintroduction projects for amphibians [32], which have been decimated by disease from the chytrid fungus Batrachochytrium dendrobatidis or Bd.33 To increase healthy frog populations, the Oakland Zoo inoculated and treated native yellow-legged frogs (Rana spp.) against Bd and released treated frogs back into wild populations [34]. Similarly, zoos rehabilitate animals confiscated from illegal wildlife trafficking [35], which are often critically ill and require intensive veterinary care and quarantine procedures to return to health. During rehabilitation, positive animal welfare is of the utmost importance to ensure that animals successfully recover and are capable of reintroduction. Thus, animal welfare directly impacts the success of rehabilitation and reintroduction programs, which are critical to the conservation of endangered species. Zoo scientists and veterinarians are experts in wildlife diseasepan class="ppr-comment-anchor" data-comment-id="5c7149a8-c84b-46c4-a08f-a348c826c5b4">36 and advance in situ and ex situconservation medicine.

In addition to bolstering the size and health of declining populations, reintroduction programs can also improve the health of surrounding ecosystems. For example, the Five Sisters Zoo, in partnership with the Beaver Trust, reintroduced Eurasian beavers in Purbank, England, where beavers are now legally permitted for the first time since the 16th century [37]. Beavers are ecosystem engineers that retain water on the landscape, which positively affects local biodiversity and reduces the impacts of wildfire on forested ecosystems [38]. Further, as a flagship species, the reintroduction of beavers can have positive psychological benefits on the community [39]. In these cases, zoos can advocate for wild animal welfare, leading science that validates welfare indicators during reintroduction and spearheading programs that promote ecosystem health and environmental stewardship. These examples showcase OHOW connections between human tolerance for conflict-prone species, wildlife health and welfare expertise, and the positive impacts on ecosystem health and human wellbeing.

Beyond reintroductions, zoos can help protect and restore habitats that benefit wildlife as well as human health and wellbeing. For example, the American Association of Zoo Keepers initiated the Acres for the Atmosphere program, which plants trees in local communities around zoos [40]. In addition to supporting biodiversity and wild animal welfare, higher canopy cover from tree plantings promotes human health by providing shade and improving air quality, as well as promoting psychological wellbeing [41,42]. For example, walking on forest trails and hearing birdsong are associated with reduced stress and increased happiness [43-45]. Past research has shown that these opportunities to experience nature are not equitable, and, through discriminatory practices, underserved communities in urban areas may be restricted from nature [46,47]. Therefore, zoos have the unique opportunity to provide equitable experiences that connect people to nature and wildlife. Zoos with free or low-cost admission, community engagement initiatives within underserved communities, and accessible, educational content are particularly well-suited to bridge this gap. OHOW highlights the connections between wildlife conservation, human wellbeing, and animal welfare, helping zoos to create win-win outcomes for people and the planet.

Many zoos engage with the activities described above, but relatively few connect their programming in animal care, conservation, and community engagement using the OHOW framework. Notably, initiatives in zoos have largely focused on the One Health framework rather than the broader OHOW. For example, one of the first and largest One Health initiatives in zoos is based at the St. Louis Zoo’s Institute for Conservation Medicine, which hosts an annual One Health Fair in partnership with local medical and veterinary schools [48] and surveyed local communities to inform One Health messaging [49]. Broadening this initiative to incorporate animal welfare science in relation to environmental health and human wellbeing will undoubtedly strengthen the utility of this initiative. As previously stated, positive welfare is a critical component to successful medical interventions and wildlife conservation.

Recently, Lincoln Park Zoo launched a One Health Initiative to optimize wellbeing for humans, animals, and cities [50]. This initiative focuses on how urban environments affect the health and wellbeing of local wildlife and the public health impacts of human-wildlife interactions through partnerships with external organizations as well as collaborations with internal welfare scientists and community engagement experts. Explicitly calling attention to the OHOW framework may expand the applicability of this work and broaden awareness of animal welfare in urban environments.

The examples above highlight the importance of partnerships for OHOW initiatives to succeed. OHOW is inherently interdisciplinary; no single person can be an expert in all the many relevant fields spanning medicine to landscape ecology to animal welfare science. We argue that zoos are well-positioned to serve as hubs for OHOW teams. As non-profits, zoos can facilitate partnerships with multiple post-secondary institutions as well as with public health agencies 51 and private industry. Further, although public opinion about zoos is nuanced and dynamic [52], zoos often have long-term relationships with local community organizations and are public facing, facilitating projects involving community engagement. As an example, Toronto Zoo hosted the University of Toronto for an inaugural network-building event for the University’s recently developed One Health Consortium [53]. These types of partnerships position zoos as leaders in advancing the health and wellbeing of wildlife, people, and the habitats we share.

We encourage zoos to consider OHOW as a unifying framework that strengthens the connections between animal care, community engagement, and conservation. Partnerships, both internal and external, are crucial to the success of OHOW initiatives, and so building relationships with experts in diverse disciplines can expand the scope and impact of zoo-led collaborations. Advancing such interdisciplinary thinking can help position zoos as leaders in protecting wildlife, public health, and ecosystems around the world.

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