White-eared Hummingbird in Michigan!

A bird in Michigan thought originally to have been a Broad-billed Hummingbird has now been identified as a White-eared Hummingbird. This is a pretty spectacular record for Michigan, but makes me wonder why we don't often get these type of hummingbird rarities in Illinois. I would be willing to bet that, solely because of population density, there are more hummingbird feeders in Illinois than in any surrounding state, so why aren't more rarities being reported?