The number of ticks in Scotland could rise by 99% over the next 50 years according to new modelling by mathematicians at the University of Stirling, with even the most optimistic of predictions suggesting they will increase in population by a double.  

Ticks are tiny spider-like creatures that are usually found in grassy or wooded areas and can spread viral and bacterial infections, including Lyme disease. If global temperatures are limited to a one degree Celsius rise by 2080, the prevalence of ticks will increase by 26 percent but it’s a lot more concerning if temperatures rise by four degrees Celsius.

That would see the number of ticks in Scotland almost double with a 99% increase by 2080. Only the highest peaks of Scotland will remain too cold to maintain tick populations, according to the research.

World leaders promised in 2015 to try to limit the long-term temperature rise to 1.5C to help avoid the most damaging impacts on the world. Mathematicians in the University of Stirling’s Faculty of Natural Sciences have developed a new model which predicts tick density under varying climate change scenarios and produced maps which show what areas of Scotland will be affected the most.


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Professor Rachel Norman, who led the study which was published in the Royal Society journal Interface, said: “The model predicted an increase in tick densities and a spread of tick distribution over Scotland for all climate warming scenarios by 2080.

“The strength of these predicted increases in tick density varied depending on the habitat. While woodland habitats were predicted to experience the highest absolute increases, the largest proportional increases were predicted for the slopes of mountains, known as montane habitats.

“Many of these areas that were predicted to be tick-free under recent climatic conditions were predicted to become warm enough to allow sustained tick populations by 2080.”

Professor Norman and her team developed a powerful tool that is dynamic and mechanistic, yet mathematically relatively simple so it can be adopted by non-specialists. It could be adapted to predict disease risk in the future.

Professor NormanProfessor Rachel Norman (Image: Stirling University)

Professor Norman said: “Scotland is an ideal country for pioneering this approach as the issue of ticks and tick-borne disease risk is of increasing concern with reported increases in tick abundance and Lyme disease incidence.

“This modelling has allowed us to identify which geographic areas and habitats might be particularly vulnerable to increased tick densities owing to climate warming.

“While we developed the approach to predict tick densities over Scotland, it could be easily used for other areas and other vector species, and pathogens could be added to the model, enabling predictions of disease risk.

“Indeed, this methodology could be used more broadly to understand the dynamic response of populations over time to a variety of environmental changes and provides a neat new method in the modelling toolbox for researchers to choose from.”