Scientists track a wide variety of animals, from butterflies to great white sharks, in order to study how they use their environment, which foods are important and to gain insights into behaviour and condition of the creatures as well as to identify key breeding areas that may need protection. Miniaturisation of electronics and improvement in battery technology is making it possible to follow even the smallest birds and insects on their migrations. Satellite technology allows us to track the position of animals anywhere on the planet, while crittercams and accelerometers give us a ringside view of their behaviour. "Is it diving, running or sleeping? We can follow animals into great wildernesses without having to be there," says John Fryxell, an arctic ecologist at the University of Guelph, Ontario, Canada.