adders

Froglife Online Research Conference 2026

May 21, 2026 by Admin

Join our FREE 2026 Online Conference and explore the latest research, conservation work and discoveries relating to the UK’s amphibians and reptiles.

Hear from expert speakers on a fascinating range of topics, including the impact of Froglife projects, slow worm translocation, toadlet emergence, adders in Cornwall, predator-induced tadpole behaviour, and insights from Citizen Science Dragon Finder data.

A fantastic opportunity to learn more about the research and conservation helping to protect our native species.

REGISTER HERE

See below for more details (these are subject to change)

Conference Agenda

Presentations Summary

What our animals are doing this month

April 1, 2026 by Admin

Written by Kat Richards, London Blue Chain Trainee, and Andrew Wood, Green Talent Trainee.

April is a wonderful time to head out into nature – flowers are blooming and birdsong fills the air. If you take a walk to visit your local pond, you might be rewarded with some fascinating amphibian life.

Frogs and Toads

Although the peak of breeding season for the common frog and common toad is beginning to wind down, there’s still plenty to see! Whilst there will still be mating pairs of common toads within the water, April is a great time to see both frog and toad tadpoles emerging from eggs laid in ponds during March.

Immediately after hatching, both frog and toad tadpoles will show very little movement. They often remain attached to vegetation or their spawn, absorbing nutrients from the yolk reserves still within their bodies. However, after a few days you’ll be able to see them swimming around the pond, grazing on algae, biofilm and plant debris in preparation for their eventual metamorphosis into froglets and toadlets.

Frog tadpoles may gather into loose groups, with individuals coming and going freely, whereas toad tadpoles will form dense and highly synchronised shoals as they move about the pond.

If you’re unsure what you’re looking at, pay attention to the colour – frog tadpoles are speckled gold or brown, whereas the toad tadpoles are usually jet black.

Newts

While the frog and toad breeding season is drawing to a close, our newt species’ breeding season is still in full swing! The breeding season is the easiest time to differentiate between the sexes, as the males of most species develop an impressive crest.

In order to attract a mate, the male newt, whether that be smooth, palmate or great crested newts, will perform a captivating vertical aquatic ‘dance’ within the pond, showing off his crest and fanning his tail to waft his scent towards her. The female newt will then decide whether to mate with the male and allow him to fertilise her eggs.

As each fertilised egg is laid, she will use her hind legs to carefully fold them one by one into the leaves of submerged plants, keeping them protected from predators until they are ready to hatch within 2 – 3 weeks.

Some early newt larvae may already be hatching in April, while many eggs are still developing. After hatching, the larvae remain among aquatic plants, where they begin feeding on tiny invertebrates such as water fleas and insect larvae as they grow.

Try visiting a shallow, clear pond just after dark with a torch and you may be able to spot a smooth, palmate, or even a great crested newt – and don’t forget to record your sightings on our free Dragon Finder app!

Adders

Snowdrops: tick…Toad migration: tick…Warmer weather: tick(ish)…Longer days: definitely!

These are all the signs the adder needs to wake up out of hibernation and start to warm itself up after months tucked away. In late March and early April adders across the UK are waking up and are hungry.

Firstly, they shed their skin and start their new year with a brand new outfit. The females become bronze with a black diamond pattern. Whilst the males a silvery grey with a black diamond pattern.

At this time, the males perform a “dance” together which is all to impress a mate. This can be viewed most commonly in April and is a tangled, energetic battle to obtain the best basking spots and dazzle the females. This is a key time for them and is when they are most easily and commonly seen, but also most vulnerable.

The adder is a shy and retiring reptile, who will often move away at the first sign of people. However, due to their sleepiness from the cold and eagerness to mate, they can allow you to get closer than is comfortable to them. Being the only venomous snake in the UK; they demand respect and should not be handled or touched.

Although bites are rare, they can occur, especially to dogs. Keeping dogs on leads and young children out of longer grass in heathland and known adder locations is essential to keep both adders, dogs and people safe.

New Adder genetics study: implications for Conservation

October 2, 2024 by Admin

Written by Jenny Tse-Leon, Head of Conservation & Impact, Froglife

adder A new study published today by ZSL’s Institute of Zoology, the University of Cambridge and Froglife highlights important implications for conservation of translocating adders.

Researchers studying an adder population in eastern England found that a population formed by the release of seven individuals managed to establish a population despite low genetic diversity – although there may have been an additional, unlicenced translocation at a later date. DNA samples found the genetic signature of the translocated snakes in the population, indicating that the translocation has been successful over the long term. However, there was also evidence of reduced genetic diversity, likely due to the small number of animals involved in the translocation.

The study was initiated after the 2015 discovery of a stillborn clutch of five adders still in their amniotic sac, raising the question of inbreeding in the population. Genetics samples of the stillborn clutch were collected as part of the Garden Wildlife Health project, a national wildlife disease surveillance scheme.

Analysis found that the clutch sampled was likely fathered by more than one male. However, the reasons behind stillbirth could still be genetic, as well as environmental maternal effects.

Despite being given some protection by the Wildlife and Countryside Act, adders can still be moved to new sites (translocated) without the need for this to be recorded or monitored – meaning very little is known about its impacts on adders. The population in this study was known to come from the introduction of seven adders from a development site 20km away, eighteen years previously, to a reserve now managed by Froglife. This provided a rare opportunity to study the impacts of a small translocation on the resulting population – making it one of few, long-term genetic based studies following an adder translocation.

Adder populations in the UK are severely declining, particularly small populations, due to habitat loss, habitat fragmentation, human disturbance and consequentially inbreeding as populations become increasingly isolated. While misconceptions about adders have led to their persecution, these snakes are not dangerous if left alone and are an important and culturally relevant part of the UK’s natural heritage.

Professor Trent Garner, researcher as ZSL’s Institute of Zoology said: “Adders are declining in numbers across Western Europe, and we need a better understanding how translocations could be used to reverse these declines and restore their numbers. Population genetics can be used to understand the more long term outcomes of translocations in terms of reproduction and population growth. Careful management and ongoing monitoring are key to ensuring future populations are genetically healthy and able to grow and flourish.”

Since managing the reserve, Froglife has carried out annual reptile surveys showing a supposedly healthy and likely expanding population resulting from this translocation. This study found however that the adder population has a low genetic diversity in comparison with published data from similar sized adder populations which is typical for a bottleneck in the population history. The cause of the stillbirth clutch might have been a result of maternal fitness, which could either be a result of inbreeding or another factor such as disturbance from dog walkers, mountain bikers and trampling of vegetation. Whatever the reason, female adders often have only one litter in their lifetime, so the loss of the whole clutch can have a significant genetic and demographic impact on a population, especially an isolated population with low genetic diversity. In this study the loss of four females in the clutch is significant in a population already showing a relatively low proportions of females. It highlights the need for protection of small populations in particular and ensuring connectivity between different populations.

“The discovery of a clutch of stillborn adders was very worrying however the outcomes of the research are reassuring for this population. The study shows the value of long-term monitoring and the need for ongoing funding to enable this to happen. It would also not have been possible without the support of our committed volunteers.” Jenny Tse-Leon, Head of Conservation and Impact at Froglife.

All About Adders

August 1, 2024 by Admin

Written by Charles Bonnett, Transforming Lives Trainee.

The common European adder (Vipera berus) is one of three native species of snake found in the UK. It is unique amongst our native snakes in it’s ability to produce venom, contributing to their undeserved dangerous reputation. Beyond this reputation, they are notable for their distinct physical characteristics, unique population distributions, and place in folklore and mythology.

Physical Characteristics

Adders are small but stocky, growing up to a length of 60-80cm. They can be found in several colourations, varying from silver-grey in males to brown and copper in females. Melanistic adders can also be seen rarely, in which the increased amount of black pigmentation portrays a uniform black colour. Their distinct zig-zag pattern which extends down their back is also one of their most recognisable physical traits, and can be an ideal characteristic to look out for should you catch a glimpse of what you suspect may be an adder. Keep an eye out for a reddish iris as well, as this can be a distinctive feature.

Distribution and Habitat

The adder is notable for its ability to survive in northerly habitats, where it has been recorded as far north as the Arctic Circle; amazingly, this means that no snake can be found further north than the adder. Adders prefer open habitats, such as heathland, moorland, and sea cliffs. Ideally, their wider habitat contains a diverse and sporadic vegetation structure, and comprises of transitional zones between connected habitats; this offers suitable protection from predation, access to locations suitable for basking and hibernation, and abundant prey.

Hunting Behaviour and Diet

Whilst we’re on the topic of prey, adders will eat a range of animals, but have a preference for small mammals, such as voles and mice. They will also eat small amphibians, including frogs and newts, and they may try their luck with nesting birds. In warmer weather, they adopt a more active hunting approach, whilst during colder conditions they prefer ambush-style tactics. Once they have locked onto their potential target, they immobilise and subdue it via their venom, after which they consume their victim whole. Remarkably, due to their ectothermic nature and slow digestion time, they can survive on very small quantities of food – as little as a single small mammal a month!

Adders and Humans

Adders and humans have had a long and complicated history. In English folklore, an adder on your doorstep was considered a bad omen; likewise, serpents more generally have historically been associated with deception and evil.

Our modern relationship continues to become more intricate. Adders are a protected species under Section 9 of the Wildlife and Countryside Act 1981. It is therefore illegal to injure, kill or sell this species.

Despite this, adder populations are struggling in the UK. As we discussed earlier, many people are fearful of adders – despite the fact that they very rarely attack humans and are very reserved – which unfortunately results in undue prosecution. Similarly, human activity, including infrastructure development leading to habitat loss and fragmentation, human-driven climate change, and pesticide use, have further negatively impacted adder populations.

Ultimately, adders deserve an opportunity to continue to co-exist alongside humans. Their remarkable ecology, ecological importance, and unique characteristics surely emphasise the need for continued education and conservation surrounding our amazing adders.

If you see an adder, or any other reptiles, you can record your sighting on our free Dragon Finder app, which will assist with our reptile conservation efforts.

Adders: are they still common?

March 1, 2024 by Admin

Written by Chloe Davey, Transforming Lives Trainee.

To answer this question let’s talk a little about what adders are. They are a stocky, venomous snake (the only one native to the UK) with adults measuring between 60-80cm in length and can be found throughout the UK except for Northern Ireland. Adders were once a common sight to behold, particularly in the countryside, but in the last decade alone their numbers have seen further declines with each passing year. It is predicted that adders will become extinct in the near future, 2032 to be precise! I’ll discuss the main threats that have led to this decline which could lead to the end of this stunning creature.

Habitat Loss – A common threat to a species decline, whether it’s building more houses, more roads or expanding agricultural land. In Europe alone, the expansion of agricultural land and poor habitat management is believed to be the most detrimental for adder populations.

Persecution – It is illegal to kill, injure or harm an adder, but there are individuals that disregard these laws and will actively seek them out to eliminate them. There is a common misconception that adders are dangerous due to their venomous bite, but they will only bite as a last resort to defend themselves. There have been 14 recorded human deaths from adder bites since 1876, the last being in 1975.

Pet Trade and Venom Extraction – Unfortunately, adders are yet another species being exploited for profit from the illegal pet trade and venom trade. Snake venom is used for studying medicine and finding cures, but it can also be used for producing harmful drugs.

It’s heartbreaking knowing that a species like the adder could be wiped out in the next decade. I’ve had such an amazing experience with Froglife researching them and surveying them in person. I hope I’ve made you more aware of the threats facing adders and if we work together, hopefully we can give this amazing creature a chance of survival and see a population growth.

We need your reptile records! If you see adders or any other reptiles out and about, please use our free Dragon Finder app to record them. All data is sent to the NBN Atlas and will help us in our research to conserve reptiles and amphibians.