We build a novel system of instruments for remote tracking of free ranging animals in nature environments using the emerging technology of mobile, delay-tolerant, wireless sensor networks. This system is expected to provide an order of magnitude improvement, both qualitatively and quantitatively, over the current, state-of-the-art systems. Qualitative improvement includes an ability to collect location information as well as timing, location, and duration of contacts among individuals. Quantitative improvements include an order of magnitude enhancement in accuracy of collected data, an order of magnitude reduction in instrument and labor costs, and significant ease in manging the entire system. We develop the hardware and software prototypes of the proposed instrument and test them extensively in lab, paddock, and field settings.