Late in the 1990s, Nick Klomp was studying short-tailed shearwaters, one of the most common bird species along Australia 's eastern coastline. During the breeding season, the shearwaters build their nests on off-shore islands. While one parent tends the nest, the other flies out to sea in search of food. A crucial question in Klomp 's research was how the bird populations interacted with the marine species they feed on. He used a combination of tracking satellites and small transponders attached to the birds to track where they flew within their nesting territories. To everyone 's surprise, data returned by the new technology showed that instead of making short sorties close to their nests, the shearwaters undertake long migrations (Klomp et al. 1997; Klomp and Schultz 2000). They travel several thousand kilometres to and from Antarctica each year during the southern hemisphere summer (Figure 10-1). Klomp 's discovery had many implications, not only about the ecology of shearwaters, but also about species interactions and food webs in Antarctic waters.