Scientists in the UK and Switzerland have reported a rapid decline in common toad (Bufo bufo) populations across both European countries since the 1980s. The study, published in PLOS ONE, was lead by scientists working for the UK charity Froglife and the University of Zurich.
In the UK, the data was collected from 153 sites as part of the Toad’s on Roads scheme, where every year thousands of volunteers carry the toads across busy roads during their annual migration to their breeding ponds. Both teams analysed 30 years worth of data from this scheme as well as an equivalent one in Switzerland.
The results show that on average in the UK, common toads have declined by 68% since 1985, with the biggest drop in population size seen in the south east of England. Populations in west England and Wales have shown an overall decline, however, these numbers have remained stable for the past 10 years.
Reasons for this decline are thought to be a combination of an increase in road deaths due to more cars being present on roads, habitat loss and the expansion of urban areas as most common toad populations live outside of protected areas.