The common hippopotamus can spend up to 16 hours a day immersed in rivers and lakes. Lumbering out of the water at night, these herbivores graze on tropical grasses and consume 80 to 100 pounds in one meal.  

By daybreak, having eaten their fill, they return to their daytime resting area to rest, digest and, eventually, eliminate. This natural process results in millions of tons of hippo dung entering Africa's aquatic ecosystems every year.  

However, as distasteful as that might seem, the hippos' deposits actually serve an important ecological function. A new study by UC Santa Barbara's Douglas McCauley and colleagues reveals that the organic matter produced by hippos is a source of nutrition for a variety of river fish and aquatic insects. The researchers' findings appear today in the journal Ecosphere. READ MORE (UCSB's The Current)