Limited resources and too many animals are hard realities confronting many zoologic institutions.
What happens when zoos are too successful at what they do?
Over the years, zoologic institutions in the United States have devoted increasing attention to providing the animals in their collections with the best veterinary care, nutrition, environmental stimulation, and conditions for reproduction.
As a result, some species are reproducing in captivity at a higher rate, creating an unforeseen moral and ethical problem for zoos faced with economic and husbandry constraints: what do you do with the surplus animals?
Dr. Albert H. Lewandowski, chief of veterinary services at the Cleveland Metroparks Zoo, tackled this challenging issue with his presentation "Surplus animals: the price of success" at the Animal Welfare Forum, Oct. 11 in Milwaukee.
Surplus animals, Dr. Lewandowski explained, are not necessarily animals that are unwanted or unneeded. Rather, they are considered extra because zoos must deal with the realities of limited space, the costs of housing, feeding, and care; and the goal of keeping gene pool strains pure.
Some animals create a temporary, easily remedied surplus problem. For instance, when an unpaired male or female is waiting to be placed with an appropriate breeding partner, they may be kept briefly in a solitary environment or unnatural grouping while a suitable match is located.
Sometimes, however, unpaired animals are good for public awareness. Smokey the bear of the National Zoo and the gorilla Massa of the Philadelphia Zoo were widely recognized symbols of their zoos, attracting public attention and generating needed revenue.
Excess male offspring pose a problem. Members of bachelor groups might be inclined to fight, resulting in injury and often requiring that more aggressive individuals be isolated. The idea of aborting male fetuses to avoid a surplus has been considered, but as Dr. Lewandowski pointed out, this generates public relations concerns that few zoo managers are willing to face.
Animals that can't reproduce because of age or infirmity are considered surplus. They serve no practical purpose except for being public favorites. Exceptions are animals that function as an integral part of the group, such as gorilla "aunts" who help raise and care for the young.
Hybrid animals, genetic oddities, aged animals, and those with untreatable illnesses are other classes of surplus. They raise a slew of troubling questions for zoo managers, who must weigh the benefits of keeping the animals against conservation goals.
Most zoos usually keep surplus animals in a primary exhibit or in an off-exhibit area. These conditions are problematic, however. When kept in a primary exhibit, the animal oftentimes ranks low in the social order and is subject to abuse and injury or runs the risk of injuring a valuable breeding animal. In the off-exhibit setting, living conditions are often less desirable than the main exhibit area. If off-exhibit placement is long term, it raises quality of life questions.
Zoos incur considerable expenses looking after their collection. Providing a large carnivore such as a tiger with food, shelter, keeper time, and veterinary care during its lifetime can cost a minimum of $25,000, according to Dr. Lewandowski. Primates are usually more expensive to maintain, he added.
Zoos desire first and foremost to solve their surplus problem by giving their animals to another zoo. If that's not an option, managers might work with registered animal suppliers who cobble together transactions with zoos in other countries or with institutions that were unaware a surplus animal was available.
Zoo managers typically go to great lengths to keep a surplus animal out of the hands of unqualified people and hunting ranches. But sometimes, their efforts are unsuccessful and the press widely publicizes these failures, undermining the positive changes created by the Department of Agriculture and American Association of Zoo Veterinarians, according to Dr. Lewandowski.
Private breeders are another possibility. Most of these individuals run institutions with high standards and are concerned more about animal welfare than profit. Occasionally, placement of certain animals, such as neonates and the injured, with a private breeder might be a viable alternative.
The two most controversial options are using surplus animals for legitimate medical research and, failing that, culling. Allowing a surplus animal to be used for research can create public relations problems, Dr. Lewandowski admits, but he believes the zoo community should be more vocal about supporting medical research that has benefited humans and animals.
"Warehousing" an animal until it dies that has, for whatever reason, outlived a useful and productive life, is morally and ethically suspect, according to Dr. Lewandowski. Zoo managers are responsible for doing everything in their power to see that a surplus animal is taken care of. But when there are no other options, a responsible steward must make a difficult choice.
Zoos need to recognize that responsible animal management often involves difficult and unpopular decisions that ultimately benefit the greater good of the collection, Dr. Lewandowski said.