Okay, maybe it is more politically correct for me to refer to feral cats as a non-native species… rather than wildlife.
To my mind, an animal born in the wild is wild.
I have been researching online in an effort to broaden my own perspective, but am mostly finding that researchers are beginning to reevaluate some efforts of TNR.
Here's one:
http://joomla.wildlife.org/documents/cats_tnr.pdf