Passenger Pigeons--Interesting Random Facts

I've been reading The Silver Age Teen Titans Archives: Volume 1, which contains reprinted comics from the 1960s.  In the first reprinted issue, from 1964, the villain is Brom Stikk, and the plot revolves around the fact that passenger pigeons were once so common in America, and are now completely gone.

Image from: https://marswillsendnomore.wordpress.com/2013/07/27/robin-kid-flash-and-aqualad/braveandthebold054_13-teentitans9/

(see here and here for more).

I was curious, so I Googled it, and found the Wikipedia article:

The passenger pigeon or wild pigeon (Ectopistes migratorius) is an extinct species of pigeon that was endemic to North America.

It mainly inhabited the deciduous forests of eastern North America and was also recorded elsewhere, but bred primarily around the Great Lakes. The pigeon migrated in enormous flocks, constantly searching for food, shelter, and breeding grounds, and was once the most abundant bird in North America, numbering around 3 billion, and possibly up to 5 billion.

Passenger pigeons were hunted by Native Americans, but hunting intensified after the arrival of Europeans, particularly in the 19th century. Pigeon meat was commercialized as cheap food, resulting in hunting on a massive scale for many decades. There were several other factors contributing to the decline and subsequent extinction of the species, including shrinking of the large breeding populations necessary for preservation of the species and widespread deforestation, which destroyed its habitat. A slow decline between about 1800 and 1870 was followed by a rapid decline between 1870 and 1890. In 1900, the last confirmed wild bird was shot in southern Ohio.^[2][4] The last captive birds were divided in three groups around the turn of the 20th century, some of which were photographed alive. Martha, thought to be the last passenger pigeon, died on September 1, 1914, at the Cincinnati Zoo. The eradication of the species is a notable example of anthropogenic extinction.

I found this interesting because:

1) I had never heard of passenger pigeons before, but this 1964 children's comic treats it like their extinction was common knowledge.  Is this a forgotten piece of history?  Did more people know about passenger pigeons in the 1960s, and then it just faded out of public memory?

(Of course it could be just me, but, I ran this by the my mother, sister and brother-in-law, and they had never heard of the passenger pigeon before either.  What about you, dear reader?)

2) It's interesting the huge scale of the reverse, huh?  This went from being the must abundant bird in North America to being extinct. That's a pretty remarkable change.

There's tons more interesting material on the Wikipedia page: everything from their vocalizations, to their relationship with humans to (perhaps most interestingly) the potential resurrection of the species.  Check out the Wikipedia page if you have time.