Animal tracking collars have proven incredibly useful to biologists providing insights into range, physiology, and environmental interaction. Current collars rely on scheduled sampling of GPS that must be preset at deployment (though advanced ones can modify the schedule through radio communications). This work details the design and development of a third generation of Mountain Lion tracking collar that can identify animal behavior in situ using advanced onboard sensors. The power-aware collar relies on triaxial accelerometers and magnetometers and signal processing techniques to classify behavior and dynamically scale its sampling for higher fidelity during interesting periods and sleeping power hungry sensors during uninteresting ones. An analysis of sensor performance and down selection is presented, along with software and hardware required to implement the collar. The resulting collar is capable of sampling its primary sensors at a high data rate (50Hz/5Hz respectively) and still last over three years on a typical battery using a low power processor. Data is logged to an onboard microSD card, and several steps have been included to ensure data integrity and recovery in the case of faults in the microSD card. It is shown that the largest power draw on the system will be the VHF/UHF radio link, and that the embedded processor on the collar should be used to minimize the time spent transmitting data by using a dedicated symbol table to encode behavior and positions for interesting events in the animal life.