Research: The effect of roadkill on wildlife populations

31st May 2023

The problem of roads

A new review studying how hedgehog populations are affected by road mortality has been released by Lauren Moore of Nottingham Trent University. Funded by PTES, the study looks at the factors in animal populations which are directly or indirectly influenced by roadkill, and proposes study methods to identify consequence in populations.

There are currently around 21.6 million kilometres of roads globally, and as they continue to expand, there is growing concern about the increasing number of animals being killed by vehicles. However, the exact effects of road mortality on local populations of wildlife are little understood.

Existing research

The researchers looked at 83 studies conducted on roadkill and populations of different species of animals, and found only 13% gave enough information about local populations to be able to utilise the data. The study found five different population factors which were affected by road mortality, including sex and age biases, annual roadkill percentage, overall mortality and long-distance movements.

Of all the species studied, female-biased mortality was more common than previously thought and considered to have more serious consequences for local animal populations. Overall, 27% of deaths within wild populations were attributable to roadkill.

20% of hedgehog mortalities came from hedgehog-vehicle collisions and 8.7% of the studied hedgehog population were killed on roads. This emphasises how important it is to look at local factors when assessing road mortality as factor such as road layout and habitats can have different effects.

Looking ahead

The researchers advised that future studies should ensure that population data is collected when looking at road mortality rates, as this is essential for creating road management strategies.

Through her roadkill research , Lauren has also published a review of road mortality mitigation measures. She will be publishing her full PhD thesis soon.

Read the full study here.