Posted: May 19, 2017 at 3:48 pm Free-ranging domesticat cats kill 1.3–4.0 billion birds and 6.3–22.3 billion mammals annually in the United States and are likely the single greatest source of anthropogenic mortality for US birds and mammals. They are considered one of the top 100 worst invasive species. submitted by /u/remotectrl to r/Awwducational [link] [comments] Source: Reddit: TGIOKDI Upvoted Leave a Reply Cancel replyYou must be logged in to post a comment.