When you weigh upward of 6,000 kilograms, you tend to make an impression—literally—wherever you go. Such is the case with the African elephant (Loxodonta africana), which, according to new research, is a boon for dozens of other, much tinier species.
As elephants walk through the forest or savanna, they leave big footprints behind them—sometimes 30 centimeters deep. These marks then fill with water, creating microhabitats for other forms of life. Researchers at Germany's University of Koblenz-Landau and other institutions analyzed the contents of 30 footprint pools in Uganda. They found that at least 61 different microinvertebrate species from nine different orders had made the pockets of water home, including mites, mayflies, backswimmers, leeches and gastropods. Tadpoles also showed up.
All told, the oldest footprints held the highest levels of biodiversity—probably because of a buildup of leaves and other organic detritus, which may serve as food. The study results were published online this past summer in the African Journal of Ecology.
The tally suggests that elephant footprints may have a place within the life cycles of several species and within the food web itself. “Who would have thought that something as innocuous as elephant footprints could be fundamental” to so many other species, says George Wittemyer, chair of the scientific board of Save the Elephants, who was not involved with the study.
The researchers acknowledge that this work is in its early stages and more needs to be done to understand how heavily the tiny denizens rely on these footprint worlds. Nevertheless, the study adds to a body of research showing elephants play vital roles in their ecosystems (such as seed dispersal via their large manure contributions), and lead author Wolfram Remmers of Koblenz-Landau says it serves as one more reminder of what we could lose if the poaching crisis in Africa continues.