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Much more than just collisions – roads have wide footprints in arid environments

Roads have wide footprints in arid environments

The impact of roads extend much further than their actual physical boundaries with important implications for ecology and evolution of the surrounding biota. These effects also vary substantially along aridity gradients.

Drs Richard Dean (DST/NRF Centre of Excellence: Percy FitzPatrick Institute of African Ornithology), Colleen Seymour (South African National Biodiversity Institute), Grant Joseph (University of Venda) and Stefan Foord (C·I·B Core Team Member) reviewed current literature to explore wildlife responses to roads at the arid end of the spectrum.

Drylands are predicted to cover 50% of the earth’s land surface by 2100, and while human infrastructure will certainly penetrate even further and faster into these remote areas, only 20% of studies explore the impacts of roads on wildlife in arid regions. From evolutionary changes in the frequency at which grasshopper males call through to road-side bird communities dominated by scavengers with resultant competition effects, roads in arid regions have interesting but mostly negative impacts on biota. Effects mediated by characteristics associated with arid landscapes such as sparse vegetation, boom and bust cycles, increased productivity of road verges relative to the surrounding landscape, and the increased reach of light and noise pollution.

The search is on for factors associated with roadkill hotspots and the development of road side detection systems which often don’t have to be high tech and expensive. Key areas for future research would include the importance of roadkill in local food webs, the impact of the removal of individuals by roadkill on the structure of the local animal communities and services such as pollination.

“The impacts of roads in arid regions differ quite markedly from those in more temperate areas” says Dr Richard Dean “and would be a rewarding field for future research, particularly in key areas such as the importance of roadkill in local foodwebs.”




Read the full paper

Dean, W. R. J., C. L. Seymour, G. S. Joseph, and S. H. Foord. 2019. A Review of the Impacts of Roads on Wildlife in Semi-Arid Regions. Diversity 11, 81; https://doi.org/10.3390/d11050081.

For more information, contact Richard Dean at lycium@telkomsa.net