… huge herds of large animals, the new study published May 16 in the journal Nature Communications suggests. And it … 4,000 hippopotami defecate 8,500 kg of organic matter each day in river pools where they congregate. These feces settle … Michigan State University. https://news.yale.edu/2018/05/16/plural-hippo-well-one-very-dirty-river?utm_sou… May 17, …