What does “tracking” mean in this case? Is the device supposed to transmit its current location (how obtained?) elsewhere, store its current location periodically on an SD card, emit a signal that a person with a directional receiver can locate, or …?
In the latter case, there are tiny radio transmitters that can be strapped to the leg or wing of a small bird, and function for months at a time.
Keep in mind that GPS requires a clear view of the sky to determine location, and generally does not work indoors or strapped under a vehicle.