Bald eagles disappeared from the island in the 1960s. Just across the bay a chemical company had been making DDT and dumping it into waterways. A survey two decades later found a hundred tons of the stuff in local ocean sediments.
The bald eagles got nailed because they primarily prey on water species. Golden eagles took over the island and because they primarily prey on land-dwelling animals, the local fox population was being decimated. This is an example of how ecosystems unravel.
Bald eagles, which do not tolerate golden eagles in their territories, are being reintroduced to the island. Once reestablished they will drive off the golden eagles, thus sparing the endangered foxes.
Not to flog a dead horse, but the following comment is illustrative of the tension between animal welfare groups and conservationists:
Of all the efforts to restore Santa Cruz Island, it is the pig-eradication program that has caused the most controversy. The Channel Islands Animal Protection Association, the most vocal critic, has called it a “slaughter” that is cruel and “neglects scientific inquiry … in a mad dash to kill a species that has existed on the island since 1852.”
The Nature Conservancy is working quietly and methodically to slow the mass extinction event (the destruction of the planet). Their method is simple: Gain control over viable habitat. They are experts at it and manage to do it in any number of ways. For example, in Borneo, the Conservancy helped the indigenous Dayak Wehea tribe establish the Wehea Orangutan Protected Forest and earmarked annual funds to help manage it.