'"Despite the industry pointing its finger at the wild birds, it's just not there," said Michael Osterholm, who directs the Center for Infectious Disease Research and Policy at the University of Minnesota. "It was not the source of widespread transmission to many operations throughout the Upper Midwest.”'
http://www.mprnews.org/story/2016/03/01/bird-flu-outbreak-mystery
Also maybe of interest, if you haven’t seen:
https://www.researchgate.net/publication/286012981_Steiof_K_J_Mooij_P_Petermann_2015_Die_Wildvogelthese_zum_Auftreten_hoch_pathogener_Vogelgrippeviren_-_aktueller_Stand_und_kritische_Prufung_der_Position_des_Friedrich-Loeffler-Instituts_Stand_Juni_201
In German, but English summary includes:
"Wild birds are dead ends for HPAI viruses. If they die, the virus vanishes as well.”
– ie Dead Ducks Don’t Fly.