Stanley Temple (formerly from here in Ohio), at UW-Madison, and others, are quoted here:
showing the profound effects of cats on bird populations.
I'll try to keep Pooser inside most of the time. 
 [Pooser is John's cat who from report can't catch a fish in a barrel. DB]
--John Blakeman

 By the way, for those who might be wondering Pyewacket and Squirrel  never go outside and never even ask. 
And for me, beyond the fact that I'm an inveterate saver of stray animals, my adoption of the neighborhood's stray cats saves hundreds of wild birds every year.