It is approximately 15 minutes before sunrise, and we are standing in the middle of a marsh to listen to a bird call that sounds like static TV. The call belongs to the endangered California Ridgway roadstead, a brave but shy bird that inhabits the swamp. The rails are both the heroes and the antagonists of a conservation paradox unfolding here in the San Francisco Bay.
The ecologists we serve are trying to save the birds, but they are also trying to eradicate the invasive weed that birds have come to trust. And that begs a difficult question: what if, to save an endangered species, we really have to preserve an invasive one?
No one really wants the weed, called a Spartina hybrid, anywhere near the bay. Our interviewed subjects certainly did not: they work for the Invasive Spartina Project, an entire organization dedicated to the disposal of the plant. The hyper-aggressive grass crowds out native species, eating acre upon acre of tidal mud that countless migratory shorebirds desperately need. The eradication effort has been in full swing for more than 10 years, and while they have removed roughly 95 percent of the invasive weed, that last 5 percent is littered with endangered rails that thrive on it.
The story is quirky, but the questions it raises are big. What do we do when an invasive species starts to do something good in an ecosystem? How much money and time should we spend fighting an invader, or saving a threatened species, or both? And what happens when we come to a standstill like this? Take a look at the video above to dive into the discussion and decide for yourself on that bird call.