A week later, another father and son in the same area saw what they at first thought was a large goose, but later decided was a large bat, when they were overflown by something with "a distinct human figure about 6 feet in height per my estimates."

"It was blackish/grayish in color and had an enormous pair of wings that must have been 8 to ten feet in width."

That height and wingspan estimate sounds about right for a sandhill crane you only saw for a few seconds, and their feathers are, in fact, grey. They could easily appear a bit darker in flight when backlit by the sun.

In fact, many of the sightings sound about right for a sandhill crane, once you remove the narrative and just look at the creature's description. Whatever these people are seeing, it's described as being roughly as tall as a man, with a six to ten-foot wingspan. It is grey or black in color, and sometimes people say it has red eyes. Sandhill cranes have a distinctive red coloration around their eyes.

That leaves us in a bit of a pickle. The sandhill crane migration happens every year, but this flap of sightings is fairly unique. So what happened? What's different this year?

Likely not much, honestly. I think that there are a couple of possibilities here: 1. Some people have actually seen something strange, and their reports are shaping the mundane misidentifications that follow, or 2. The initial reports were themselves a misidentified animal, and we're witnessing a sort of folkloric snowball effect. The first possibility is what I find most likely, since a handful of sightings couldn't possibly be a misidentified terrestrial animal if the witnesses are to be believed--and at this point, we have no reason not to believe them.

After the first reported sightings began to gain traction online, when further witnesses typed "flying creature Chicago" into Google, they were met with reports of giant flying bats and mythical Mexican witches; and, not surprisingly, they decided that whatever they saw was similar enough to what those other people had seen that it must have also been a monster. And I don't know that it wasn't, but I do know that the sandhill crane migration is normally over by August, and so too, I think, may be our flying humanoid flap in Chicago.

Yours in Impossibility,

Tobias