During February and March, volunteers head out after dark with buckets and florescent jackets to stand on roads across the UK. These are the toad patrols, and they help an amphibian with love on its mind.
Early spring is the start of the breeding season for common toads (Bufo bufo to scientists). A warm, wet evening is the perfect cue for males to embark for a pond where they hope to find a mate. Females usually arrive a few weeks later, but they only stay long enough to mate and spawn.
Males, who outnumber the females, must engage in gladiator-style battles to win mates. In one pond scientists studied in Sweden, there were four males for every female. The scientists reported intense competition, with only 20.5% of males breeding successfully. The male grabs hold of the female for several days, and as the female begins laying eggs, he fertilises them. Toads lay a long double string of eggs that are black in colour, unlike the mass of eggs laid by frogs.
After that, the parents begin to depart the pond. The spawn they leave behind takes around 16 weeks to grow into toadlets. You’ll often find the toadlets leaving a pond en masse during a wet summer evening, darting for cover to avoid getting eaten. Outside of the breeding season, toads spend their time in woods, grassland and gardens until spring begins and they start their migration.
Stubbier than frogs, with shorter legs, toads crawl to breeding ponds, which can be up to 5km away. Their destination is typically a familiar one. One study found that over 80% of adults that survived to breed the following year returned to their pond of origin.
You may wonder why a species that has made this migration for millions of years needs the help of a toad patrol. Toads are equipped for the journey to their breeding ponds, but they are not built to withstand the obstacles and barriers that people have put in their way. The natural world has been split apart by roads. Britain has 247,800 miles of road, on which 20 tonnes of toad is estimated to be squashed each year.
What toad patrols have taught us
If a road has lots of toads crossing in the spring, it can be registered with Froglife and a patrol set up to ferry toads across it. The charity Froglife is committed to the conservation of all amphibians, reptiles and their habitats, and has coordinated toad patrols for over 35 years.
Toad patrollers are tasked with recording how many amphibians they help across the road in an evening and how many they find dead. Volunteers are also asked to record the number of days in which a patrol is active each season and how many people take part. This helps scientists understand whether any changes in recorded toad numbers are not just a result of more people submitting data. In 2023, there were 203 crossing sites in the UK, which helped over 115,000 toads to cross a road safely.
The information gathered by these patrols has shown that toad numbers have declined by 68% since 1985 in some areas of the UK, but the reasons are unclear. The loss of ponds for breeding and disruption to migration routes are among the most likely causes.
Roughly half of the UK’s ponds were lost during the 20th century. Those that remain are in a generally poor state. It is no surprise that toads have continued to decline despite the best efforts of volunteers, who have been venturing out on dark, damp evenings since the early 1980s.
One study analysed how effective the patrols were for conserving toads. The authors mentioned a period in Cambridgeshire in the mid-1990s, when volunteers dwindled each year because of declining toad numbers at crossings.
This period still saw significant toad casualties, and it took several years before people realised that toad populations could be reduced by road traffic. By this point, local ponds, despite being protected, saw only small numbers of toads breeding and hardly any toads at the crossing because the local population was so depleted.
Mr Toad from Wind in the Willows may have enjoyed zooming around in his sports car, but reckless driving on rural roads is causing real toads to decline. With ever smaller populations, toads need all the help they can get to ensure that adults arrive at their breeding ponds safely.
The Toads on Roads project is one way you can help support toads. See if there is one near you.
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Becky Thomas does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.
This article was originally published on The Conversation. Read the original article.
