Until recently, zoos primarily relied on contraception to manage their animal populations and avoid overpopulation. However, researchers are now advocating for a significant shift in approach: allowing animals to breed naturally, educating the public about conservation issues, enhancing animal welfare, and minimizing the carbon footprint by managing surplus animals through culling.
Animals in zoos live much longer than those in the wild due to the absence of food shortages and predators. This longevity, however, can create challenges for zoos as they work with limited space.
Consequently, many zoos impose restrictions on breeding for practical and financial reasons. Some have faced public backlash when culling surplus animals; for instance, the euthanasia of Marius, a healthy two-year-old giraffe, sparked widespread outrage and discussions about the ethical responsibilities of zoos in managing excess animals.
Aging zoo populations
A recent policy statement from researchers at the University of Zurich highlights that the routine use of contraception is negatively impacting both the age structure and welfare of zoo populations. Marcus Clauss, the lead author, states, “Without births, adult animals miss out on a fundamental evolutionary instinct.” He adds that zoo populations are aging, which threatens one of the main goals of zoos: to maintain self-sustaining animal populations.
Surplus animals often cannot be relocated due to capacity constraints at other zoos or the challenges associated with reintroducing them into the wild. Instead of limiting animal reproduction, the authors propose that zoos should consider respectful culling of surplus animals. “This method is logical and responsible for managing zoo populations. Additionally, it can help zoos achieve their educational and conservation goals,” Clauss emphasizes.
Educating the public about the natural life cycle
“Over 700 million people visit zoos globally each year,” notes Andrew Abraham, a co-author from Aarhus University. “Zoos have a remarkable chance to educate the public on animal mortality and natural cycles. By sidelining death, zoos create unrealistic expectations about life in nature.”
Zoos play a vital role in conservation efforts, especially as many species are currently endangered and more may become so in the future. “It’s crucial for zoos to sustain breeding populations and have trained staff capable of caring for young animals. We don’t want a collection of aging animals with veterinarians focused only on end-of-life care,” Abraham asserts.
In-house meat supply improves carbon footprint
As more animals are born, culling surplus zoo animals may contribute to the environmental sustainability of zoos. For instance, one German zoo manages to provide up to 30% of the meat needed for its carnivorous animals from its own population, which helps reduce its carbon footprint and reliance on commercially slaughtered animals.
Although the culling of popular animals can be contentious, studies indicate that public opinion may be more nuanced than how the media portrays it. “Zoos must educate their visitors about the real-life challenges of animal population management,” Clauss argues. “Open and honest communication can change public perceptions and help align views with sustainable long-term practices.”
