No, I don't hate cats—I've even met a few that I really like—but as we've discussed here, here and here, I do contend that a house cat's place is in the home. Feral and outdoor cats take a heavy, unnatural toll on many wild bird species, including but not limited to upland species and waterfowl. According to ABC, cats kill an estimated 500 million birds per year and have contributed to the extinction of 33 species.
Therefore, any study that could persuade people to keep their kitties indoors is useful to the bird conservationist, and the one touted by ABC is pure gold: It found that in urban environments, house cats make up an astonishing 13 to 45 percent of the average coyote's diet. To put that into perspective, there are coyotes out there eating somebody's cat for nearly every other meal.
So, save the birds and don't feed the coyotes. Keep Fluffy indoors.