On average, mammals move distances two to three times shorter in human-modified landscapes than they do in the wild. These findings are published in the prestigious journal Science by a large international team lead by researchers at the Senckenberg Nature Research Society and Goethe University Frankfurt. It is the first time this topic has been examined at a global scale and for many different species at once. The authors highlight that these results may have far reaching consequences for ecosystems and in turn, for society.

Most mammals are on the move every day while searching for food, to find a mate or to seek out shelter. Some larger mammals like zebra generally move longer distances, while smaller mammals, such as hares, usually cover shorter distances. The research team, led by biologist Dr. Marlee Tucker, Senckenberg Biodiversity and Climate Research Centre and Goethe University Frankfurt, has shown that the extent of these movements is significantly reduced in human-modified areas. In these areas, mammals move distances that are only half to one third of what they cover in more natural areas.

In this study, Tucker and 114 coauthors from various institutions, including Prof. Nico de Bruyn from the Mammal Research Institute, University of Pretoria, collated terrestrial movement data from 803 individuals across 57 mammal species from around the globe. To do this they used the data portal, Movebank, which archives movement data from researchers across the world. “Our study looks at everything from hares to wild boars to elephants. The scientists in our team equipped individual animals with a GPS tracking device that recorded each animal’s location every hour for a period of at least two months,” said Tucker. The researchers then compared these data to the Human Footprint Index of the areas that the animals were moving in. The index measures how much an area has been changed by human activities such as infrastructure, settlements or agriculture.

The researchers are concerned that the reduced travel distances could affect ecosystem functions that hinge on animal movements. “It is important that animals move, because in moving they perform important ecological functions like transporting nutrients and seeds between different areas. Additionally, mammalian movements bring different species together and thus allow for interactions in food webs that might otherwise not occur. If mammals move less this could alter any of these ecosystem functions,” says Tucker.

These results are published in full in: Tucker, M.A. et al. 2018. Moving in the Anthropocene: Global reductions in terrestrial mammalian movements. Science 359: 466-469. DOI: 10.1126/science.aam9712