Soil movement by burrowing mammals : a review comparing excavation size and rate to body mass of excavators

Abstract

Mammal burrowing plays an important role in soil translocation and habitat creation in many environments. As a consequence, many burrowing mammals have at some point been studied in an ecosystem engineering context. From a geomorphological point of view, one of the focus areas of burrowing mammal research is on the amount of soil that is excavated and the rate at which this happens. As such, reviews exist on the volumes and rates of sediment removal by burrowing mammals in specific environments or for specific groups of species. Here a standardised comparison of mammal burrowing across a broad range of burrowing mammal species and environments is provided, focussing on both burrow volume and excavation rate. Through an ISI Web of Science-based literature search, articles presenting estimates of burrow volumes and/or excavation rate were identified. Relationships between species body size and burrow volume/excavation rate were explored and the influence of sociality and method of burrow volume estimation was assessed. The results show that, although bigger species construct bigger burrows, it is the smaller species that remove more sediment per unit time at larger, sitelevel spatial scales. Burrow volume estimates are, however, independent of species sociality (solitary vs group-living) and method of burrow volume estimation (excavation-based vs moundbased). These results not only confirm previously established relationships between species body size and burrow volume, but, more importantly, they add to this, by exploring larger scale impacts of burrowing mammals along a body size gradient.