In this paper we have proposed a Wireless Sensor Network (WSN) System and developed sensor node to monitor the Poultry farm and detect the highly pathogenic avian influenza virus in Chickens. WSN's have tremendous potential and play a key role in such monitoring applications. The developed wireless sensor node monitors the body temperature and movement of the Chickens. Based on sudden variation in body temperature and slow movements of the Chicken, early detection of virus is possible. The proposed low cost WSN System was developed with the use of open source technology-ARDUINO (open electronics prototype and open source). © 2013 Springer-Verlag.