I have to admit I never heard of Shifting Baselines Syndrome before reading Jon Mooallem's Slate article, "The Last Buffalo Hunt." You can read it here: http://www.slate.com/articles/arts/culturebox/2013/05/william_temple_hornaday_how_a_taxidermist_helped_save_the_buffalo.html (and in the shamless self promotion department, Jon does mention not only my friend William T. Hornaday, but also The Most Defiant Devil).
Shifting Baselines basically means each generation redefines its "norm." The best way I can illustrate it
He liked to roam the woods, and, as he wrote in his An American Life, "exploring the local wilderness." (p. 31) These rambling adventures led the future president to comment that he lived a childhood out of a Mark Twain novel. Reagan didn't miss the passenger pigeons and other wildlife that Hornaday did, because Reagan never knew them. He created a baseline without the the species that defined Hornaday's. What Hornaday considered a loss was something outside the younger man's perspective, or baseline. I think this is an interesting and intellectually useful concept that I will think more of in the future.