How giant earthworms have transformed the Isle of Rum’s landscape
Kevin Richard Butt does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.
Renowned for a thriving and intricately studied population of around 900 red deer, the Isle of Rum, part of Scotland’s Inner Hebrides, is often considered an outdoor laboratory for scientific research. But the earthworms on Rum are equally remarkable. These invertebrates act as “ecosystem engineers”, actively shaping the landscape, often after humans have left their mark on this remote island.
My investigations over 30 years have uncovered how people have influenced the current fragmented and uneven distribution, diversity and abundance of earthworms on this national nature reserve.
While taking my geography students on field trips to Rum in the mid-1990s, I realised there was scope for research on earthworm ecology. One of my PhD students was studying soil development here and she quickly alerted me to differences in earthworm numbers found below different species of trees planted in the late 1950s. More worms lived below birch and oak trees than beneath pine trees or on unplanted moorland. This discovery spurred me into action.
