Examples of the act's success include recovery of the bald eagle, peregrine falcon, and Aleutian Canada goose. Few of the species that have been listed as threatened or endangered have recovered to the point that they can be removed from the list. Clearly, the time for cost-effective conservation measures is when wildlife and their habitats are still common and before, not after , they have become significantly reduced or isolated. As local populations within a species decline in number and become separated from one another, species becomes more vulnerable to extinction, and recovery becomes increasingly difficult and costly. Another important cause of extinction, particularly on islands, is the introduction of exotic species, which often prey on or out-compete native species.
Prevention is the best strategy for endangered species management.
Early detection of species at risk provides managers with more options and greater flexibility in designing and conducting successful recovery programs. Quick action and flexibility also reduce the need for costly crisis management and its potential for adversely affecting human activities and disrupting local or regional economies. Unlike most of the world, Alaska's ecosystems still remain largely intact with little loss or fragmentation of habitat. An early warning system, emphasis on habitat protection, and a broad ecosystem-wide perspective on natural resource management will strengthen our ability to maintain healthy populations of Alaska's native species and minimize the necessity of costly reactive management. Close evaluation and monitoring of federal candidate and sensitive species and identification of Alaska's state species of special concern offer wildlife managers a good opportunity for heading off future problems before they reach crisis proportions.