Mysterious giant bird in San Antonio?

This photo purports to show hunters from the late 1800s or early 1900s
with a large 'thunderbird' they have shot

Now, you'd think if there was a ginormous bird gliding over a major U.S. city that's home to a couple big Air Force bases, lots of people would see it. So would radar, airplane pilots and Homeland Security.

But isolated reports of a giant black bird with a wingspan of up to 20 feet continue and the latest is from ... a San Antonio newspaper carrier in a very populous part of town? Why are UFO's, Loch Ness monsters and undead dinosaurs always seen by people whose credibility is only slightly higher than Lindsay Lohan's? Why aren't they ever seen by a priest or a stadium full of 50,000 people?

Is it an ancient "thunderbird" from Native American mythology? A holdover from the Ice Age? A crow whose wingspan grows with each retelling? An urban myth come to life?

I dunno. But this is the only story you're ever likely to read that uses the phrase "slightly less extinct."