Last month, with little fanfare, the U.S. Fish and Wildlife Service removed two tropical birds, the Mariana mallard and the Guam broadbill, from its list of species that are endangered. The birds are extinct, having joined a growing list of animals that have disappeared from the face of the Earth.
The announcement that these two birds, which were native to the islands of the western Pacific, had vanished forever elicited little attention. Their numbers had been declining for decades. And few people, other than the most avid bird enthusiasts, even knew what they were or had ever seen them. So there will be few who will mark their passing with the same nostalgia or sense of loss that might accompany the disappearance of a better known species like the snow leopard, the Siberian tiger or the black rhinoceros — all on the brink of the same abyss.
The fact that the extinction of these two creatures was virtually a silent one is a tragedy. Both were the product of millions of years of evolution. Both were connected to a larger network of species that interrelate and depend on one another in many ways that still remain a mystery to science. And both succumbed to the same types of human- induced pressures that threaten so many other animals in this country and elsewhere in the world: habitat loss, over-hunting and the introduction of nonnative species against which they have little or no defense.
Many would ask why we should care that these two birds are no longer here. The answer is that we now know enough about how the world is put together to recognize that each species on Earth plays a role in nature. When one disappears, it is a harbinger of trouble. Just how or when or if the extinction of one species will affect us in any material way is difficult to know. However, there are stark examples of how our disregard for other life forms has imperiled our own survival.
Take, for example, the case of Easter Island. This remote, barren island in the South Pacific, which is best known for its huge, mysterious stone statues, was once covered by a subtropical forest. But its Polynesian inhabitants eventually deforested the island, driving most of its tree species into extinction along with every species of native land bird. With no wood available to build boats for fishing, and the soil so depleted that crops could not be grown, an estimated 90% of the human inhabitants died of starvation.
There are many different reasons why we should rail against extinction. Biologically, because each species is part of a larger, complex assemblage of living things, we should strive to protect them all, particularly because we don't understand how each piece fits with the others. There is also a moral reason. It is that Earth's creatures, great and small, are not simply here for our benefit but are here with us in the world. As such, we have a fundamental responsibility to treat them all with respect and a sense of stewardship.
We are clearly failing in this task. There are more than 12,000 species of animals and plants that are known to be threatened, 1,816 of which reside in the United States. And the list gets longer every year.
From the earliest days of life, many species have come and gone. To a certain extent, extinction is a natural event. Up until modern times, it is believed that one to two species per million vanished annually. We are now losing them far faster, at a rate that is estimated to be up to 1,000 times as high as in the past. Indeed, many scientists believe that by the middle of this century an astonishing 25% to 50% of all existing species will be on the path to extinction.
We have both a practical and an ethical responsibility to ensure that this does not happen. Every species that disappears represents one less strand in that remarkably intricate web of life of which we are a part and which ultimately sustains us.
There were no bells that tolled the departure of the two Pacific birds. But they should have tolled for us, as a sad reminder of what we have lost and as a warning for the future.
Joshua Reichert directs the environment division at the Pew Charitable Trusts.
Copyright 2004 Los Angeles Times