The results of a study, carried out by National Charity Froglife, and recently published in The European Journal of Wildlife Research, has shown that the peak migration of both common toads and common frogs coincides with the waxing phases of the moon, reaching its climax around the full moon, as they make way to their breeding sites.

Whilst previous research has shown the effects of rainfall and temperature on this annual journey of frogs and toads, up until now, no lunar research has been undertaken or recorded. The research, carried out by Dr Laurence Jarvis at Froglife, using Froglife data at 43 sites across the UK over 4 years, showed that the highest numbers of common toads (Bufo bufo) and common frogs (Rana temporaria) occur on warm and damp evenings close to a full moon.  The findings are crucial in providing guidance for amphibian conservation initiatives such as ‘Toads on Roads’ as they will help inform patrollers on the most effective timing to help toads and frogs cross roads safely, at a time when common toad populations are under threat. A study undertaken by Froglife in 2016 revealed that common toads have declined by 68% over the past 30 years in the UK. If this continues the UK could lose all of its common toads by 2030.

Common Toads are very particular about where they breed and migrate back to their ancestral breeding ponds each year, following the same route, which often leads to them crossing busy roads and being stuck down drains. Froglife has been co-ordinating ‘Toads on Roads’ patrols manned by volunteers up and down the country for around 30 years. Migration can run from as early as January to as late as April and patrollers can’t always be out every night, so they need all the pointers they can get.

Despite both common toads and common frogs being more vulnerable, visually, to predators when moving under a full moon, the fact that they synchronise their movements to migrate and breed in large numbers, may dilute this risk. Overall, this study has implications for the conservation of both species.

The main findings of this research show that both common frogs and common toads have their peak migration close to a full moon. Both species are explosive breeders, which means that they are only at breeding ponds for one or two weeks per year. Therefore, it is crucial that individuals synchronise their movements to ensure highest mating success. Both species become active when the first mild weather occurs in spring. However, the timing of this is highly unpredictable, due to variations in local conditions. Therefore, we suggest that the first activity of common frogs and common toads occurs in the first mild weather and they then synchronise peak breeding activity at ponds at the next full moon. This ensures the highest number of individuals are at ponds for breeding.

Froglife are also running a Wildlife Tunnel Campaign to help our amphibians and small mammals cross the roads safely. Once it has reached a substantial number of signatories Froglife will contact the relevant Government departments, all UK Local Authority Transport departments, ecological consultants and developers. You can sign the campaign here.

Finally, Froglife were also delighted to host a Wildlife Road Mortality Webinar in March where wildlife conservationists from around the world came together to discuss their work in relation to mitigating the death of wildlife on our roads. You can read all about it here and also watch a recording of all of the speakers here.

By: Jules Robinson, Froglife