When elephants tromp through the swampy forests of the African nation of Uganda, they leave behind enormous footprints. The tracks often fill with rainwater or groundwater. Scientists recently found that 60 different species, including various kinds of beetles, tadpoles, and worms, live in these foot-shaped “ponds.” 

The finding suggests that Africa’s elephants, which are threatened by illegal hunting, play an important role in their forest ecosystem—a community of organisms interacting with their environment. “The species in these ponds would certainly be affected if anything were to happen to the elephant population,” says Wolfram Remmers, a biologist at the University of Koblenz-Landau in Germany who led the study.