Downsizing the animal kingdom.

In a recent investigation, researchers at England's University of Southampton conclude that smaller creatures will dominate the animal kingdom in the next 100 years, and that the average body mass of mammals will shrink by about 25 percent as large species increasingly become extinct. The scientists made their predictions after analyzing the conservation status, reproductive biology, physical characteristics and diets of some 15,500 mammal and bird species. While "this downsizing may be happening due to the effects of environmental change … ironically, the loss of species that perform unique functions within our global ecosystem could also end up a driver" of shrinking species, says lead author Robert Cooke. [Extracted from the article]