Olivia Judson has a very nice post up at the New York Times today about the role of predators in ecosystems.  She points out all the ways that predators effect the behavior of a host of different animals--from elk in Yellowstone to grasshoppers in your back yard--and how these changes, in turn, can alter entire plant communities and shape whole ecosystems.  The important role that predators play drives a lot NRDC’s wildlife work.  Anyway, check it out.