What is a U.P. Specialty Species?

The U.P. species list currently stands at 388. Not one of these 388 species is endemic to the U.P. So what, then, should constitute a U.P. specialty species? For instance, I think most birders would agree that Spruce Grouse should be on this list, even though it occurs in other northern states as well. But what about, say, Kirtland’s Warbler, which now occurs in small numbers across the U.P. each summer, but whose stronghold is in Michigan’s Lower Peninsula? For that matter, what about many of North America’s most beautiful warbler species, which can be seen in transit each spring and fall in most eastern states, but many of which nest in the U.P., and hence can be seen here all summer? And what about those species of the far north which have been documented in the U.P. only a handful of times, e.g., Northern Wheatear, Ross’s Gull, etc.? In other words—and obviously—the answer to “What constitutes a U.P. specialty species?” is a personal, even quirky, one. Here’s mine: a U.P. specialty species is a species that occurs regularly in the U.P., even if only in small numbers, and is rare or absent from most of the rest of the United States. In short, a U.P. specialty species is a species that most birders would target on a trip to the U.P.