This study demonstrates a fact that should be obvious to most; that all species in an ecosystem, no matter what their size, serve an important function in that ecosystem. This was also the crux of yesterdays article in the Guardian which suggested that we conserve smaller 'useful' species other larger iconic ones, such as tigers (see link below).

http://www.theguardian.com/environment/2014/oct/05/threatened-species-cannot-afford-to-lose-age-of-extinction