Research on bird flu in cows shows how efficiently it has spread among mammals NBC NewsNew study confirms mammal-to-mammal avian flu spread Phys.orgHalting the Bird Flu Outbreak in Cows May Require Thinking Beyond Milk The New York TimesHuman H5N1 cases in the U.S. are rising. That’s bad timing with flu season, bird migrations just months away CBC NewsColorado reports 2 more avian flu infections in poultry cullers University of Minnesota Twin Cities