If you read about these, it is really hard to fathom the sheer numbers of them that there were. At one point passenger pigeons made up something like ¼ of all the birds in North America. Flocks were a mile across and would take several hours to fly by. They were slaughtered in droves, even after laws were put in place to protect them. It is absolutely disgusting how the birds were treated. They would sew the eyes shut on one for some horrible reason, set it on a stool and use it to lure other pigeons in (hence the term stool pigeon) to be killed. That was just one of the ways they were killed in mass numbers. Unfortunately, these birds were so easy to kill even by non-human predators that they relied on massive numbers to make sure they survived as a species. The last one, named Martha, died September 1st, 1914 at the age of 29.
I've never had pet birds, but I almost did. My kids saw these two in a yard near us when they were out walking our dogs one evening. They came back and got me because my kids know that I will help any animal. The one on the right was injured, so I picked her up and put her in a bag I had. The other one refused to leave her and let me grab it as well, even though it was perfectly healthy. We took them to an emergency vet. I wasn't sure what they were. They look like doves, but almost the size of seagulls. Come to find out they are called king pigeons. We named them George and Gracie and set up a space for them in our front room until we could figure out what to do with them. This picture was taken right after I gave Gracie her antibiotics. It was actually very funny watching a pigeon try to figure out how to spit. She was not pleased with me as you can tell, she's the very fluffy looking one. George had to be kept back from her because he'd try to keep me from medicating her. It was really sweet how protective of her he was. They eventually went to a fantastic wildlife rehab center about an hour from us.