I keep thinking of the effort to save the Red Cockaded Woodpecker , an endangered species that likes to live in long leaf pines at least 80 years old. The bird is limited by the availability of cavities for nesting and roosting, which it digs out itself. One problem is that other woodpeckers and also flying squirrels take over the cavities. At one point in one intensive effort to save a Red Cockaded Woodpecker population, technicians climbed each cavity tree once a month to check the cavities for invaders. If squirrels were found they were removed and killed. How much human interference with the natural order is appropriate in order to save the natural order?