Even though climate change is dramatically affecting the biosphere, our understanding of its effects on biological communities is poor. The Southern Ocean is an ideal natural laboratory to the impact of regional and global climate change because of the sensitive interactions between temperature, ice extent and species. Measuring variations in penguin populations can tell us a great deal about climate change, but could tell us even more if we understood the mechanisms the underlie the dynamics of penguin colonies. Taking advantage the major advances that have been made in microelectronics recently, this project will fit penguins with hugely powerful yet tiny state-of-the-art transponders and data recorders. The project will provide the first complete global and unified picture of penguin population dynamics, uncovering the processes that drive their numbers and the effects climate change is having on them.