Written collaboratively by participants on our Wild Memories project in Somerset
Year of the snake
Written by Emma Byrne, Transforming Lives Trainee
2025 is the Year of the Snake according to the Chinese Zodiac. In light of this, let’s look at the three native snake species in the UK.
Adder – The UK’s Only Venomous Snake
The adder is the only venomous snake in the UK. This small, stocky species thrives in woodland, heathland, and moorland habitats. Females incubate their eggs and can give birth to as many as twenty live young! Adders hibernate starting in October and emerge in March to bask in the sun. Adders are easily recognized by their distinctive dark zig-zag pattern and red eyes. Males are more silvery-grey, while females are often lighter or reddish-brown. Although venomous, they are shy and prefer to avoid humans.
Grass Snake – Britain’s Longest Snake
Grass snakes can grow over a meter, making them the longest snake in the UK. They are typically grey or green and feature a yellow and black collar around their neck. As the only egg-laying snake in the UK, they can lay up to forty eggs in sheltered spots such as compost heaps. Grass snakes are commonly found in England and Wales, especially near garden ponds, where they feed on amphibians and fish.
Smooth Snake – A Rare Species
The smooth snake is rare, found only in a few sandy heathland areas in Dorset, Hampshire, and Surrey. This protected species is part of reintroduction programmes, aimed at preventing its extinction in Britain. Smooth snakes are ectothermic, basking in the sun and hibernating from October to April. Males compete for females, who give birth to between four and fifteen live young in September.
Throughout 2024, grass snakes have been spotted at our Boardwalks and Hampton reserves! If you visit one of our public reserves, keep an eye out this spring as they emerge from hibernation to bask in the sun!
Remember to report your sightings on our free Dragon Finder app.
What our animals are doing this month
Written by Charles Bonnett, Transforming Lives Trainee
It’s February and we’re settling into the New Year. For our animals, February can represent a period of transition, as the first signs of spring start to stir them from their dormancy.
For some amphibians, February marks the beginning of their habitual migration to their breeding ponds. Male common frogs typically arrive first, ready to attract females. In warmer, southernly regions of the country, mating may have already occurred by late February and frogspawn may be present. Likewise, during warm, wet evenings, common toads will begin their migration to their ancestral breeding ponds; these epic journeys can sometimes span kilometres. Some of our three native newt species, smooth, palmate, and great crested newts, will similarly begin to rouse from their dormancy, though will likely remain more inconspicuous than their frog and toad counterparts.
In comparison to amphibians, our reptiles are more temperature-sensitive, and so will mostly maintain their dormant state throughout the cold February days in order conserve their energy. Though, this does not mean that reptiles will be completely inactive during this period; a warm spell may stir adders and common lizards from their inactivity, after which they may be seen basking on south-facing slopes to regulate their body temperature in preparation for spring.
Generally, there is a degree of variation in when a member of a species may exit brumation, in part influenced by regional variation in weather, where earlier activity may be observed in more southerly regions. A further notable impact on this transition is our ever-changing climate. Our winters are becoming milder and less predictable, leading to our amphibians and reptiles exiting their dormant state prematurely. This early emergence can be dangerous, as it can leave the animals exposed to unpredictable weather, such as cold snaps. Likewise, it can cause the expenditure of energy during colder periods which may be difficult to recoup as sources of food will be rarer.
Overall, then, February can be a transitionary period from dormancy to activity for our amphibians and reptiles, and will likely continue to be with greater frequency due to our changing climate.
Remember to report any sightings of our species (including eggs and young) on our free Dragon Finder app.
Ponds in winter
Written by Paul Arestides, Transforming Lives Trainee
At this time of year, especially January and February, our weather can turn cold with ice, frost and snow. It’s a good idea to keep an eye on our garden wildlife ponds and implement these handy tips below when needed.
Amphibians like frogs, toads and newts tend to brumate on land during the colder weather, so its always a good idea to have spaces of the garden left untouched. Compost heaps, log piles or rocky places are good for them to settle down and help protect them from frost.
If you have a pond, or plan to build one, make it deep enough so it will not freeze completely (at least 60cm for amphibians) frogs may overwinter in the deeper areas, so this will give them the best chance to survive. Invertebrates like beetles, water boatmen and dragonfly larvae will dive to the bottom of the pond and stay dormant in deeper water.
Contrary to popular belief, melting a hole in the ice will not help the amount of oxygen diffusing into the water- although it can help amphibians like newts that need a hole to come up to the surface to breathe. Oxygen can be produced simply by having oxygenating plants growing in the pond. If there is heavy snow, remove this from the surface ice with a brush to allow sunlight into the water- allowing the plants to continue photosynthesising and creating oxygen.
Do not break the ice as this can send out shock waves that can kill overwintering creatures. Tipping warm/boiling water into your pond isn’t a good idea either as this can trigger animals to come out of their brumation state earlier than planned.
For further tips, take a look at our Winter Wild Gardening Campaign page.
What our animals are doing this month
Written by Paul Arestides, Transforming Lives Trainee
Happy New Year to you all. It’s January and the start of 2025, our weather doesn’t seem to be getting any more predictable and the warmer winters do have an impact on our amphibians and reptiles. These animals usually rest up over winter, either in the bottom of ponds, in rocky crevices or finding places underground to brumate, hidden away from cold or freezing conditions.
As the climate warms, however, we are noticing changes in behaviour. Our winters in the UK are now generally milder and can tempt amphibians and reptiles out of their brumation state. With reports of newts and frogs in ponds in January, even in full breeding condition, is now fairly normal in southern counties. Snakes and lizards will also make an appearance when the winter sun is strong enough, and all this would have been unheard of 15 or 20 years ago.
All the evidence is now pointing to our reptiles and amphibians emerging from their slowing-down period and breeding earlier than ever before, in response to our ever-changing climate.
It is still too early to predict the implications of these changes in behaviour, but a consequence of this has been on our reserve at Hampton with delayed pond maintenance due to the higher risk of harming our pond animals as they stay active for longer. This year we will be starting our great crested newt surveys earlier in response to breeding patterns.
With an unpredictable climate it can cause issues if newts, frogs or toads breed earlier with higher risks of frozen ponds, spawn and eggs. Being more active over winter could also have negative impacts on our species life expectancy- using up energy reserves when they would normally be brumating. Food sources will be scarce over the winter months, so feeding becomes harder.
You can help us in our research by uploading your sightings of frogspawn or any amphibians and reptiles on our free Dragon Finder App – these records help us learn more about how our changing climate affects our species.
Great crested newt activity while overwintering in ponds – Information request
Written by Andrew Smart, Head of Science and Research
Froglife are interested in gathering information about great crested newts overwintering and remaining active in ponds in the UK during the months of November to February. We would appreciate anyone who has any winter records of great crested newts active in their garden ponds or local ponds contacting us by email on: winterGCN@froglife.org (see below for details).
Following a recent article on overwintering and neoteny, Froglife has been made aware of a garden pond where great crested newts continue to show activity while overwintering in the pond. While small numbers of newts have been known to overwinter, its not something that has ever been widely recorded.
Griffiths et al (2010) found that milder wet winters are linked to low survival rates in great crested newts, with overwintering animals away from the pond being unable to feed but continuing to deplete energy reserves. Investigations of the metabolic rates of overwintering alpine newt (Kristín and Gvoždík, 2014) found that individual metabolic rate was related to body mass loss, which in turn is linked to reproductive success, immune response and future survival. Griffiths et al found the implications of any potential change in climatic conditions on a regional scale could result in the loss of metapopulations while variation in survival of individual populations may be linked to changes in summer climate.
With milder winters in the UK it may be that some newts that previously adopted a higher-risk strategy (exposure to winterkill) of overwintering in ponds may find themselves able to feed and be in better condition at the start of the breeding season. Triturus carnifex (Mori et al 2017) have been found to remain present in ponds in Italy throughout the year with low numbers recorded in December, January and February. In Norway (Dervo et al 2018) great crested newts have been found to migrate as much as 1300m to find suitable hibernation sites to escape the cold; searching for hibernacula is another energy cost, dehydration and predation risk that could make partial migration a strategy that could be beneficial in warmer winters.
Partial migration is known in other newt species including the red spotted newt (Notophalmus viridens) in the USA, where a study (Grayson et al, 2011) found that animals were able to switch overwintering strategy and that density influenced the probability of remaining in a pond overwinter. Variation in reproductive success over time resulted in the maintenance of both resident and migratory strategies.
Froglife would appreciate anyone who has any winter records of great crested newts active in their garden ponds or local ponds contacting us by email on: winterGCN@froglife.org with the following details:
- dates of activity
- one of: OS Grid reference / ‘what three words’ location code/ postcode (or address of garden pond)
- Approximate area of pond
- Approximate depth of pond
- Any information about numbers seen and activity
Please remember that great crested newts are protected from disturbance under the Wildlife and Countryside Act and a licence is needed to survey. Obviously, any animal overwintering is at risk if disturbed, so please, if you are licenced don’t undertake any extensive torchlight surveys that could disturb animals and deplete energy levels; at this stage all we are interested in is a set of records to determine the extent of activity and location.
Dervo, B.K., Museth, J. and Skurdal, J., 2018. Assessing the use of artificial hibernacula by the great crested newt (Triturus cristatus) and smooth newt (Lissotriton vulgaris) in cold climate in Southeast Norway. Diversity, 10(3), p.56. Grayson, K.L., Bailey, L.L. and Wilbur, H.M., 2011. Life history benefits of residency in a partially migrating pond‐breeding amphibian. Ecology, 92(6), pp.1236-1246. Griffiths, R.A., Sewell, D. and McCrea, R.S., 2010. Dynamics of a declining amphibian metapopulation: survival, dispersal and the impact of climate. Biological Conservation, 143(2), pp.485-491. Kristín, P. and Gvoždík, L., 2014. Individual variation in amphibian metabolic rates during overwintering: implications for a warming world. Journal of Zoology, 294(2), pp.99-103. Mori, E., Menchetti, M., Cantini, M., Bruni, G., Santini, G. and Bertolino, S., 2017. Twenty years’ monitoring of a population of Italian crested newts Triturus carnifex: strong site fidelity and shifting population structure in response to restoration. Ethology Ecology & Evolution, 29(5), pp.460-473.Click for references