Ground-breaking research from the Netherlands is beginning to uncover the relationship between predator density and the spread of Lyme disease.
The research, led by Dr Tim Hofmeester of Wageningen University (Netherlands), at that time an undergraduate, focussed on the deployment of remote cameras in a selection of plots across the Dutch countryside. The aim of research was to quantitively measure red fox and stoat activity (key predators of small mammal e.g. mice) across a representative sample of Dutch countryside e.g. in area where predators are protected vs. areas where predators are controlled.
Over a period of two years, the research team trapped a variety of small mammals in the same plots where the camera traps had been deployed. For each trapped small mammal, the number of ticks were counted, in addition to being tested for Lyme disease and two other disease-causing bacteria. Additional ticks, for testing, were also captured from the test plots by means of a simple cloth drawn over the ground.
Dr Hofmeester’s research discovered that where predator density was higher, the instance of newly hatched ticks was lower, in addition to the density of infected tick nymphs. Curiously, the research didn’t demonstrate a reduction in small mammal numbers, as was thought. Instead, it appears a higher density of predators results in a change in small mammal behaviour and the use of their habitats, which reduces the risk of them becoming infected or ticks being able to secure one of their three life-cycle blood meals.
The last two decades has seen a significant spread of Lyme disease throughout the countryside and a corresponding rise in the number of reported cases of the disease. In light of the valuable information that is beginning to emerge from on-going Lyme disease / predator research, perhaps it’s time local and central government and landowners / land-managers re-think their position on predator control across the UK countryside, if we are to control the spread of this debilitating disease.
This blog was informed by research undertaken by Wageningen University (Netherlands), which was published in the Proceedings of the Royal Society B.
Image Credits: Diapicard & Lyme Disease UK