As you study images of contemporary scavengers, it’s important to realize that scavenging is an ecological strategy that goes back a long ways. There has been heated debate among paleontologists as to whether Tyrannosaurus rex was really a predator or a scavenger. This new study (http://www.npr.org/2013/07/16/202294091/om-nom-nom-t-rex-was-indeed-a-voracious-hunter) provides fossil evidence of this dinosaur’s predatory behavior. Most likely T. rex was a facultative scavenger, at times wearing the hat of a predator and at other times that of a scavenger. In this regard, T. rex is very similar to many of the species that you are analyzing in this study. A raccoon that you view at one moment scavenging from the pile, a few minutes later could be feasting on a live frog or crayfish that it captured in a nearby stream.