Opponents of protectionist policies reply that it makes no sense to say that we have a duty to preserve species because species is only a category invented by humans to group individual members. In reality, there are only individual animals that are members of a species. And, the interests of these individual animals must sometimes be overridden by the weightier interests of individual human beings. Moreover, simply because something is rare doesn't mean it is more deserving of preservation. Leprosy is rare, but we don't value it.
Rarity only intensifies the value of valuable things.
Finally, it is argued, the extinction of species is a natural and normal event. As government officials, environmentalists, and industry representatives work out the details of implementing the new regulations designed to preserve the owl, we can expect the debate over the spotted owl to subside. But the ethical issues it raises will repeatedly appear as our natural resources dwindle. How we resolve these issues will depend on how we weigh the ecological, aesthetic, and scientific benefits of preservation, the rights of animals, and an obligation to preserve species, against economic interests and human needs.