Elephants’ footprints create tiny ponds that provide miniature habitats for dozens of aquatic species, acting as stepping stones that allow these creatures to spread across the landscape. Among the many insects that tend to colonize these tracks are dragonflies, which compete with one another to become the top predator in a footprint and hold it as their territory.
Researchers examined the wildlife inhabiting 30 water-filled elephant footprints in Uganda, discovering more than 60 different species, including a large number of water beetles. They also determined that the number and types of residents within these impressions tend to vary depending upon the age of each footprint.
For example, the researchers discovered that older prints, which contain large amounts of trapped leaves and plants, provide the perfect habitat for tadpoles.
Reporting their findings in the African Journal of Ecology, the study authors describe how they then created 18 artificial footprints in order to observe how they are colonized. As predicted, those nearest to a water source tend to become inhabited first, with water beetles and spiders making themselves at home within a day of the prints being made.
After five days, the 18 fake footprints were inhabited by no less than 410 different organisms, which gradually made their way from print to print. The researchers suggest that the rapid colonization of these tiny pools occurs because they are completely lacking in predators, and thereby act as safe havens for many small critters.
However, dragonflies are no fools, and quickly recognize that the invertebrates and other small animals living in these small puddles are ripe for the picking. As such, they race each other to become the first to lay their eggs in each footprint and establish themselves as the top predator within that territory. Of particular interest are the tadpoles, which are a favorite snack of dragonfly larvae.
Summing up their findings, the study authors claim that elephants are vital ecosystem engineers, as not only do they spread seeds in their poop but they also facilitate the dispersal of small aquatic organisms, which literally follow in these elephants’ footsteps by colonizing their tracks.