When the act passed in 1973, the science of ecology was just branching from its overprotective mother, divide-and-define biology. Since then, humans have had to admit our hubris, as there is no way for us, as a species, to fully comprehend the life cycle and interactions of any other species, let alone all of the others with which every species interacts.
Because we don’t fully understand any species, we have a difficult time arguing for protection — and restored habitat more closely resembles what we think the species needs. The ESA’s single-species emphasis has preserved habitat, but quickly loses its efficacy in the face of a dynamic political situation. We risk putting all our passenger pigeon eggs in one legislative basket if we defend an ecosystem with one species. Let’s take Pombo’s impetus and really protect ALL species.