This thread could very well end up being one of the longer lived discussions on BYC. There is a lot of meat for debate here.
I have a close friend whose daughter owns a farm in Minnesota. She and her husband keep chickens. It is their long time management practice, which appalls me, to abandon the chickens to fend for themselves in the woods when their egg laying drops off. Of course, the chickens don't last long in the woods, but it doesn't seem to bother them. It would never occur to these folks that this is a cruel practice.
I was a park ranger in a previous life, and I encountered many, many abandoned pets people dumped in my parks. I did glean a bit of insight into why people seem to feel so comfortable doing this. In short, they believe all animals have a "wild" nature. Therefore, these sorts of people believe the animals they abandon have the skill sets in their DNA to cope with living in the wild.
They're terribly misguided and ignorant, of course, but this is what they believe. These are the same people who permit their dogs to run loose to harass the wildlife and more often than not, their dogs come to a violent end when they eventually confront the wrong wild animal. I've actually been lectured by these people that their dogs, domesticated over thousands of years, are "wild" and need to run free.
I adopted a hen a year ago whose owner moved and abandoned his flock, leaving them behind to fend for themselves. My hen was finally noticed by a neighbor when she saw her scratching for food under her car in her driveway. Every single other chicken in the flock had died by that point, but this one hen was lucky. She was taken to the animal shelter and now she has a wonderful home with my flock, cared for and appreciated.
This is an issue that is dreadfully common. I wish there was an easy way to change peoples mindsets, but it's not a problem that has a quick and easy solution.