Abstract: Sensing and communicating data from moving animals is described. In various embodiments a logging and communications device is attached to a wild animal such as a bird; the device senses environmental, physiological or behavioral data about the animal and communicates that data wirelessly to other devices (be they on other animals in the environment or at a scientist's base station). This enables scientists to obtain empirical data about animals in their natural environment without disturbing that environment unduly and with improved data retrieval. In various embodiments the device is physically small and lightweight whilst incorporating sensors such as global positioning systems, pressure sensor, light sensor or others and may be used solely to retrieve data or for both logging and communications.