Methods for overcoming the constraints of long range telemetry of biological information from animals: getting more useful data from small packages

Many species carry out their most interesting activities where they can not be observed or monitored. Marine mammals are perhaps extreme in this group, accomplishing their most astounding activities both distant from land and deep in the sea. Collection, storage and transmission of data about these activities are constrained by the energy requirements and size of the recording loggers and transmitters. The more bits of information collected, stored and transmitted, the more battery is required and the larger the tag must be. We therefore need to be selective about the information we collect, while maintaining detail and fidelity. To accomplish this in the study of marine mammals, we have designed 'intelligent' data logger/transmitters that provide context-driven data compression, data relay, and automated data base storage. We later combine these data with remotely sensed environmental information and other oceanographic data sets to recreate the environmental context for the animal's activity, and we display the combined data using computer animation techniques. In this way, the system can provide near real time 'observation' of animal behaviour and physiology from the remotest parts on the globe. To illustrate the approach, we will present examples of its use in southern elephant seals and beluga whales from the polar seas.