Earlier this week, two Sumatran tigers were born at Washington's National Zoo. Kids and big cat enthusiasts will be delighted — there are only about 500 of these tigers left in the wild. With 65 of these tigers now in captivity in the U.S. alone, and breeding programs like these a key objective, what should the role of zoos be in preserving species? Ideally, they should maintain close linkages with conservation programs in preserved habitats and raise awareness about wider environmental issues through the use of charismatic animals.
Roughly about 15% of threatened bird, reptile, mammal and amphibian species are currently in zoos. No zoo's breeding program is intended for a species to persist entirely in captivity. There have been great successes over the years — Przewalski's horse, the black-footed ferret, and the California Condor for example — have all been successfully bred in captivity and reintroduced into habitats. They were all on the brink of extinction and have made it back successfully.
Of course, some disagree with the use of zoos. PETA declares, "Despite their professed concern for animals, zoos can more accurately be described as 'collections' of interesting animals than as actual havens or homes." The standard of care in zoos varies wildly and there is indeed in terrible abuse. Moreover, increased stress levels from captivity inhibit the fecundity of some species. That hampers the objective of keeping these species in captivity in the first place.
Overall, those like PETA get it wrong. Zoos are indeed collections of animals, not homes. But they exist because of habitat destruction and species exploitation and are a stopgap measure against complete extinction. Those that are not for-profit operations are major components in a network of scientific institutions looking to implement what is known about the state of different species and improve the situation.
While zoos work on those issues, they also use it to raise awareness with the wider public. A lot of our modern concern with the loss of species has to do with the proliferation of zoos, nature films, and other cultural products that allow us to have experiences with nature.
But at the same time, that representational function only goes so far. When it comes to the crisis of biodiversity, the threat to the sum of all life, charismatic megafauna are only part of the story. It's biodiversity as a whole that matters. It is a potent source of innovation for medicine as a well of genetic diversity, direct use as natural resources, and as critical actors in the biogeochemical cycles that govern planetary functioning.
No matter how you spin it, the crucial nitrogen-fixing fungus or the photosynthetic phytoplankton is not going to catch the public's eye like a magnificent Sumatran tiger. We need zoos to preserve them, both for their potential role in their natural habitats, and to inspire us, as kids and grown-ups, to realize just how important biodiversity is.