in Britain ≥20 million birds/year: in USA >80 million birds/year
||Winkler, K., Fall, B.A., Klicka, J.T., Parmelee, D.F. and Tordoff, H.B. (1991) The importance of avian collections and the need for continued collecting. Loon 63, 238-46 link p.244 right column 3rd paragraph
||Churcher, P. B. and J. H. Lawton. 1989. Beware of well-fed felines. Natural History July 1989:40-46
||P.244 right column 3rd paragraph: "Churcher and Lawton (primary source) examined a poorly understood source of bird death: the domestic cat. They found that at least 20 million birds a year are killed by Britain’s cats. If cats in the United States hunt as effectively, and if cat numbers correspond to human populations, then [investigators] might expect more than 80 million birds to be killed annually by domestic felines in the United States."