Toad populations have almost halved in the past 40 years, but huge annual citizen science efforts are key to vital data collection and ongoing conservation
New research published this week, confirms that populations of common toads (Bufo bufo) continue to decline in Great Britain, reflecting declines experienced by other once-common species such as farmland birds and hedgehogs, and likely indicating wider countryside-scale challenges facing some generalist native species. The research, led by Froglife – a leading UK amphibian and reptile conservation charity – has been published in leading journal Biodiversity and Conservation, and confirms that common toad populations have declined by a staggering 41% in the last 40 years in Britain, and by 33% in Switzerland, despite ongoing volunteer action via ‘toad patrols’
The study, which focuses on trend estimation rather than the reasons for the decline, provides an update following a paper published by Froglife in 2016 that first quantified the decline of common toads in Britain. It revealed a 68% decline in 30 years (1985-2013), but since 2016 researchers have added eight more years of data (1985-2021) from annual toad patrols which has been reanalysed to produce these latest figures. These are now the most up-to-date and comprehensive statistics for common toad populations in Britain, providing what’s thought to be one of the biggest datasets ever used for tracking population trends of amphibians, with millions of toads included in the analyses. The findings will enable conversationists at Froglife to better understand population trends, where toads most need help and to implement effective conservation action to help curb the decline.
Dr Silviu Petrovan, Trustee of Froglife, Senior Researcher at the University of Cambridge and lead author of the study explains: “Although it might appear that the situation for common toads has slightly improved since our 2016 paper, today’s findings are sadly very worrying as they show vast numbers of toads are being lost every year. The base level population is much lower than it was even in the 1980s – and the decline is ongoing, confirming that we need to urgently act to protect this much-loved and once common species before it’s too late.”
“The situation toads are facing in Britain probably reflects what’s happening both in the wider rural landscape in Britain but also in Europe too, and thanks to our partners in Switzerland we now understand how toads are faring overseas. Long-term monitoring of any species is crucial to its recovery, and together I hope we can build on our findings by increasing monitoring across more of the toad’s range in Europe in order to fully-understand the wider situation the species is facing and how we can collectively help to conserve them.”
The reasons for the decline are likely numerous and complex. Road mortality is considered a major issue facing toads, combined with loss of ponds, increased urbanisation and perhaps a decline in their invertebrate prey (beetles, earthworms and slugs) in the wider countryside. Climate change is also thought to exacerbate the problem as milder winters are detrimental for hibernating toads, meaning they can lose body condition and produce fewer eggs.
Although the report’s main findings confirm a serious and ongoing decline, there are a few glimmers of hope. There appears to be regional recovery in some areas, including the south east and central regions of Britain, regions considered to have the most serious decline in 2016. But, as this is based on short-term data, monitoring in future years will be needed to confirm if toads really are starting to recover in these areas.
The study also highlights the vital contribution of volunteers, who every year help toads safely migrate across Britain’s roads in search of breeding ponds via ‘toad patrols’, as part of Froglife’s Toads on Roads project. It’s thought this annual volunteer effort has substantially reduced the rate of decline in areas where patrols are in place, enabling most adult toads at those sites to successfully breed – which is key to the species’ success.
Jenny Tse-Leon, Head of Conservation and Impact at Froglife said: “Thanks to our amazing ‘Toad Patrollers’ we have this essential long-term dataset and now understand the scale of the problem toads are facing. Without toad patrols populations in these areas would have already experienced a much steeper decline, resulting in more populations becoming locally extinct. We are so grateful to our volunteers and hope that even more sign up and help next spring.”
“This research also reiterates the need for effective government policies to do more for our common and widespread species, which is particularly pertinent in the face of the government’s current Independent Water Commission review and Planning and Infrastructure Bill amendments. We will continue to advocate for amphibians and the habitats they rely on by ensuring they’re included in policies and suitably protected, researched, and funded to not only halt but to reverse these declines. As an organisation we encourage and deliver the restoration and creation of more, and better-connected ponds and terrestrial habitats such as woodlands and grasslands, which are essential to their survival, as well as engaging local communities with this work. We need to build on these findings to make sure that toads continue to be monitored, and that we use our knowledge to halt and reverse their decline.”
The full paper can be read online here: bit.ly/uncommoncommontoads