The importance of the role that common species play would perhaps largely be of interest only to biologists if they remained common. However, systematic declines are now frequent (see the fi gure), with common species lying at the heart of each of the major pressures on biodiversity. First, common species are the main victims of habitat loss, fragmentation, and degradation. Indeed, to a first approximation, common species are habitat loss, yet our awareness of this fact is dulled by the presentation of statistics in terms of areal declines of forests, grasslands, coral reefs, and the like, rather than the numbers of individuals that have been removed.