This project investigated the role of free-grazing ducks in the spread of avian influenza in Vietnam. Professor Dirk Pfeiffer has been the Principal Investigator of this project and it was completed in March 2017. The project examined the spatial and temporal pattern of movements of free-grazing duck flocks in the Mekong and Red-River deltas. It showed the high frequency and diversity of contacts between free-grazing duck flocks, and that they were transported across district and province boundaries, mainly by boat but also by truck or on foot. The free-grazing duck value chain was described for the first time in detail. As part of this activity, so called ‘duck yards’ were identified in the North of Vietnam for the first time, where spent layer free grazing ducks are gathered before being sold to China. This mechanism could play a significant role in the spread of avian influenza virus. The project was funded by British Council’s Newton Fund, and it involved a collaboration between Vietnam Government’s Department of Animal Health, the Ministry of Agriculture’s National Institute of Animal Sciences, the United Nations’ Food and Agriculture Organization, the Royal Veterinary College in the United Kingdom and City University of Hong Kong.