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What our animals are doing this month

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August is an important month for great crested newts, as many of this year’s larvae begin their remarkable transformation into young newts.

Over the summer, the larvae have been feeding on aquatic invertebrates and other small pond creatures, growing to an impressive 5–9cm before undergoing metamorphosis. During this time, they often move into the deeper parts of the pond, where they are less active as they prepare for life on land.

Great crested newt larvae grow to an impressive 5-9cm before undergoing metamorphosis.

Warmer ponds help larvae develop more quickly, while cooler or shaded ponds can slow the process. This means some larvae may not complete their transformation until later in the autumn, and occasionally they can even overwinter in the pond before emerging the following spring.

As they metamorphose, great crested newts develop the rough skin and toxin-producing glands that help protect them from predators. Once they leave the water, the young newts will begin searching for damp, sheltered places where they can feed and eventually spend the winter.

If you’re lucky enough to spot a great crested newt, remember they are a protected species and should never be disturbed, but please remember to record them on our free Dragon Finder app to contribute to valuable research to conserve these wonderful creatures. 

Research finds the Canadian western toad shows evidence of genetic separation.

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Written by Andy Smart, Head of Science & Research

Research finds the Canadian western toad shows evidence of genetic separation – a reminder of the need to think about the conservation of every component of biodiversity.

A recent paper published this summer by scientists at the University of Ottawa[i] has found that the western toad, Anaxyrus boreas,  a species widespread across north America, shows distinct genetic and behavioural separation linked to the presence of the Canadian Rocky Mountains. Their study into the habitat preferences and genetics of two groups of toads identified that the toads on the west of the Rocky Mountains, which have a vocal sac and make advertisement calls, are a genetic group, distinct from those animals on the east and to the south of the Canadian Rocky Mountains (which have no vocal sac and are non-calling).  Their study also produced evidence of a third distinct group to the south and possibly other distinct groups to the north which may make different advertisement calls.  This paper highlights the need to consider the genetic variation within populations of even the most widespread species when we think about their conservation. Different genetic populations may have adaptations to particular climatic or habitat conditions  and so its is important to ensure we are protecting as much genetic variation as we can. People often forget that the conservation of biodiversity isn’t just about species but that biodiversity comprises three components: genetic diversity (the variation within species), species diversity (the number and abundance of species), and ecosystem diversity (habitats and ecological processes).

Western toad (Anaxyrus boreas) By Walter Siegmund (talk) – Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=9903967

The study of variation within a species can often lead to remarkable outcomes where single species are actually found to be several ‘cryptic’ species. This has been helped considerably by the development of genetic research but morphological differences and behavioural differences are important in establishing different species.  Last year, work by various natural history museums and research institutes, led by the University of Copenhagen[ii], investigated specimens of a species of Nectophrynoides, bufonid toads that are arboreal and viviparous (live bearing). Nectophrynoides viviparus was believed to be found across the  Tanzanian Eastern Arc Mountains, a region known to be of high biodiversity.  The research group investigated hundreds of museum specimens and looked at the variation in their morphology and how that related to their origin within the mountain range. Further genetic studies and audio analysis of recordings of calls from different locations found that what was believed to be one species was in fact four, distributed across different mountain peaks with the Eastern Arc mountains. The species involved, Nectophrynoides viviparus was previously identified as being of ‘least concern’ status by the IUCN but now that four species have been recognised, two are ‘critically endangered, one endangered and one vulnerable.[iii]

This speciation of Nectophrynoides and the genetic separation of Anaxyrus are examples of allopatric speciation, an evolutionary process that leads to a species becoming two or more distinct species following geographic isolation that prevents the movement of genetic material between populations. This isolation may be because of separation by, for example, mountain ranges or rivers, or it may be because of the separation of a new colonising group often isolated on ‘islands’ (and ‘islands’ in this case may be islands of habitat rather than islands in a lake or sea).

There are lots of new species of amphibians being found as more habitats are surveyed and explored but it is rare to find a new genus. In 2023, a completely new genus of toad was found from a single specimen collected in a pitfall trap on the slopes of Mouth Kenya[iv]. This small toad appears to be terrestrial but nothing is known of its habitat or behaviour other than this single specimen. Another new species identified last year was a new ‘orange toad’, found in the Atlantic rainforest of Brazil[v], this spectacularly coloured but tiny species (14mm adult) of what is actually a frog not a toad, Bracycephalus lulai, is one of 42 species within this diurnal leaf litter inhabiting genus, 35 of which have been discovered since 2000.

Brachycephalus lulai. By Luiz F. Ribeiro in M. Bornschein et al. – “A new species of Brachycephalus (Anura: Brachycephalidae) from Serra do Quiriri, northeastern Santa Catarina state, southern Brazil, with a review of the diagnosis among species of the B. pernix group and proposed conservation measures”, CC BY 4.0, https://commons.wikimedia.org/w/index.php?curid=179761023

Microhylids are another group of tiny frogs that live on the floor of rainforests across Asia and  new species are regularly identified as more forests are being surveyed. A recent paper from work in Papua New Guinea[vi]  identified six new species of the genus Xenorhina, separated by different advertisement calls and by morphological differences. This type of speciation may be sympatric; evolution of species within the same area through ecological, behavioural or genetic differences.  A population may be able to exploit different resources or microhabitats within the same  area, or may behave differently, spawning at different times or using different advertising calls. Small terrestrial frogs and toads are widespread in tropical habitats and generally not well studied because of the difficulty in surveying them and exploring their natural behaviour. I spent many nights looking at the variation in dorsal patterns of two species of Microhyla in Sabah in Borneo, Microhyla bornieensis and Microhyla perparva, and wondering how many different  species they might be[vii]. These enigmatic little frogs are the size of a fingernail when adult and live in amongst the leaves on the rainforest floor, only appearing on vegetation at heights of about 20- 40cm early in the night after rainfall.

Larger amphibian species are also being discovered, two years ago a paper was published by a group of Russian and Vietnamese scientists[viii] who had found a new population of Bufonid toads within the Bufo gargarizans species complex (a group of species that are so similar its difficult to confirm them as separate  species). These animals, which have the catchy scientific name of Bufo rubroventromaculatus, are toads with a snout-vent length of around 120mm, similar in size to the common toad, Bufo bufo, and are characterised by red blotches on their belly. Having been identified as a new species in Viet-Nam, animals collected previously in China have since been re-examined and confirmed to be the same species[ix].

Just to highlight that this expansion of amphibian species isn’t limited to Anura, in September last year a new species of mountain salamander was reported found in south-east China, during a survey of a national park[x]. There are a number of different species of Pachytriton and it appears that the isolation of different mountain ranges and mountain stream habitat has led to geographic isolation and speciation and also speciation with altitude, with different species inhabiting streams found at different altitude bands. This particular species Pachytriton cheni is found between 850m and 1350m. Also in China, in Hunan province, a species of newt, Tylotriton gaowangjienensis (another great name), was found living in the Gaowangjie National Nature Reserve[xi], breeding in ponds within coniferous and mixed forest on the mountain slopes.

Lest we get carried away and start to think that all these new species are a positive indication that things are getting better for amphibians, a paper published in 2025[xii] confirmed that while 35 species improved their conservation status between 1980 and 2004 and 86 species between 2004 and 2022, during the same time periods 482 and 306 species declined in conservation status and that overall 41% of amphibians species remain ‘globally threatened’. A recent study investigating the nature of published work on amphibians over the last four decades[xiii] found a shift from research identifying ‘declines’ to research identifying the ‘reasons behind declines’ and mitigation practice, but that there remains a lack of published work on conservation and management ‘reflecting a broader gap between research and practical implementation’. The authors highlighted ‘baseline data on species’ ecology, distributions, and abundance is crucial’ in establishing declines and that ‘researchers must remain open to unexpected drivers of species decline’. The impacts of climate change, disease, invasive species and habitat loss and fragmentation must not be underestimated and we should remember that even ‘common’ species such as the UK’s common toad (Bufo bufo) can suffer significant declines[xiv].

 

Click here for references

[i] Bergman, J.C., Enciso‐Romero, J., Pauly, G.B., Gamlen‐Greene, R., Todd, M. and Lee‐Yaw, J.A., 2026. Pronounced genetic structure associated with differences in a reproductive trait and climatic barriers in Canadian populations of the western toad (Anaxyrus boreas). Diversity and Distributions, 32(5), p.e70219.

[ii] Thrane, C., Lyakurwa, J.V., Liedtke, H.C., Menegon, M., Petzold, A., Loader, S.P. and Scherz, M.D., 2025. Museomics and integrative taxonomy reveal three new species of glandular viviparous tree toads (Nectophrynoides) in Tanzania’s Eastern Arc Mountains (Anura: Bufonidae). Vertebrate Zoology 75: 459-485 [online]

[iii] IUCN Red List of Threatened Species

[iv] Liedtke, H.C., Malonza, P.K., Wasonga, D.V., Müller, H. and Loader, S.P., 2024. A new genus and species of toad from Mount Kenya illuminates East African montane biogeography. Zoological Journal of the Linnean Society, 202(1), p.zlad160.

[v] Bornschein, M.R., Pie, M.R., Nadaline, J., Confetti, A.E., Blackburn, D.C., Stanley, E.L., Mari, R.D.B., Alves, G.S., Sandretti-Silva, G., Lima, F.F.D.A. and Ribeiro, L.F., 2025. A new species of Brachycephalus (Anura: Brachycephalidae) from Serra do Quiriri, northeastern Santa Catarina state, southern Brazil, with a review of the diagnosis among species of the B. pernix group and proposed conservation measures. Plos one, 20(12), p.e0334746.

[vi] Günther, R. and Richards, S., 2021. Description of six new species of Xenorhina Peters, 1863 from southern Papua New Guinea (Amphibia, Anura, Microhylidae). Zoosystematics and Evolution, 97(2), pp.355-382.

[vii] Zainudin, R. and Alaudin, N.A., 2018. Phylogenetic Relationships of the Sarawak Microhyla (AMPHIBIAN: ANURA: MICROHYLIDAE). Malaysian Applied Biology, 47(1).

[viii] Orlov, N.L., Ananjeva, N.B., Ermakov, O.A., Lukonina, S.A., Ninh, H.T. and Nguyen, T.T., 2024. A new record of Bufo gargarizans complex (Bufonidae, Anura) from Truong Son Mounts, Ha Tinh and Ha Giang Provinces, Vietnam based on molecular evidence with a description of a new species. Diversity, 16(7), p.361

[ix] Liu, S., Hou, M., Mo, M. and Rao, D., 2024. First confirmed record of Bufo rubroventromaculatus Orlov, Ananjeva, Ermakov, Lukonina, Ninh & Nguyen, 2024 (Anura, Bufonidae) from China, with supplementary description of this species. Biodiversity Data Journal, 12, p.e134392.

[x] He, Z., Wu, S., Wang, S., Ma, L., Zhao, N., Wu, X. and Wang, S., 2025. A New Species of Pachytriton (Amphibia: Caudata: Salamandridae) from Anhui, China. Animals, 15(20), p.3018.

[xi] Huang, J., Xiang, Y., Wu, T., Zhang, Y.X., Zhang, Z.L., Wang, B.Z., Lan, X.Y., Huang, Y.P., Jiang, H.J. and Jiang, W.S., 2024. Description of a new species of the Asian newt genus Tylototriton (Amphibia, Urodela, Salamandridae) from Hunan Province, China. Herpetozoa, 37, pp.327-338.

[xii] Borzée, A., Prasad, V.K., Neam, K., Tarrant, J., Kosch, T.A., Barata, I.M., Rais, M., Bickford, D., da Fonte, L.F.M., Wilcken, J. and Ghosh, D., 2025. Conservation priorities for global amphibian biodiversity. Nature Reviews Biodiversity, pp.1-18.

[xiii] Crawford‐Ash, J., Evans, M.J., Carvalho, T., Rowley, J.J., Garner, T.W., Muths, E. and Scheele, B.C., 2026. Evolution of research on global amphibian declines. Conservation Biology, 40(1), p.e70146.

[xiv] Petrovan, S.O., Moor, H. and Schmidt, B.R., 2025. Increasingly uncommon common toads: multidecadal, ongoing abundance decline of a widespread amphibian despite volunteer conservation action. Biodiversity and Conservation, 34(12), pp.4235-4249.

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Alien snakes are bad news for island endemics

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Roger Downie, University of Glasgow and Froglife Patron

It is common for animals that first colonise isolated islands in the absence of predators to lose the defences that protected them on the mainland: a well-known example is the dodo, a species of pigeon that lost the ability to fly after many generations living predator-free on the island of Mauritius. For his reason, we need to be vigilant in avoiding the accidental introduction of predators on to islands with vulnerable endemic species. Unfortunately, we have not been careful in the past, and accidental introductions continue to occur. In this article, I discuss some examples involving snakes.

The Brown Tree Snake (Boiga irregularis) is a colubrid, native of Australia, New Guinea and the Solomon islands. It arrived by accident on the isolated Pacific island of Guam soon after World War 2. Its population remained low and localised for some years, but during the 1960s, its numbers increased rapidly and it migrated to populate the whole island. It preyed principally on birds, but also on lizards and bats. Many of the bird species had lost their defences to predators such as snakes and by the 1970s, 15 species had been lost to the island, including three endemic species and two sub-species (Wiles et al., 2003).

Brown tree snake (Boiga irregularis), By Pavel Kirillov from St.Petersburg, Russia – CC BY-SA 2.0, https://commons.wikimedia.org/w/index.php?curid=46853510

An example recently in the news (Jones, 2026) is the Horseshoe Whip Snake (Hemorrhois hippocrepis), another colubrid, native to north-west Africa, Portugal and Spain, but not to the Balearic Islands (Ibiza, Mallorca and Menorca). In the early 2000s, this snake arrived on Ibiza, probably as eggs buried in soil attached to olive trees being shipped to the island from Spain. Since arriving, its numbers have grown very rapidly , and this population explosion has had devastating effects on the endemic Ibiza Wall Lizard (Podarcis pityusensis), formerly very abundant, but, since 2024, classed as Endangered by IUCN. The lizards are estimated to comprise about half of the snakes’ diet. Efforts are being made to cull the snake population: over 12,000 have been captured and removed since 2016.

Alarmingly, it turns out that these snakes can disperse by swimming in the sea (presumably, they did not reach Ibiza by this route earlier because the distance is too long, almost 150 km). Casbas et al.(2026) have filmed snakes swimming vigorously from Ibiza to the offshore islet of Santa Eularia, a distance of only 430 metres, and they have also collected confirmatory reports of swimming snakes observed by members of the general public. Santa Eularia is only 4.7 hectares in area, but snake traps set out there captured 58 individuals over the period September 2023 to May 2025. Surveys of the islet for wall lizards found them to be abundant as recently as 2022, but all gone by 2025. An interesting question is what motivates the snakes to set off in the sea, presumably quite a hazardous journey for a snake not normally living in an aquatic environment, and how do they detect their destination? Possibly migration is driven by competition once numbers get too high in one place, but Casbas and colleagues say that no answers are yet known to these questions.

Genetic and morphological studies of the Ibiza Wall Lizard across Ibiza, Formentera and their islets have shown there to be 30 ‘evolutionarily significant units’: this diversity is at high risk of being lost because of the snake invasion. Also lost will be the unique ecology of the islands where the lizards have major roles in pollination, seed dispersal and arthropod control.

Are there any alien snake populations in the UK? The best known is the Aesculapian Snake (Zamenis longissimus) which occurs at three British localities: near Colwyn Bay in north Wales; beside Regent’s canal in north London; and at Bridgend in south Wales. The common name of this large (140-160 cm) colubrid is derived from Asclepius, the Greek god of healing: the snakes were encouraged to live round his temples and a snake coiled around a staff became a symbol of the medical professions. The species occurs in Europe from France east to Iran, but has not been native to the UK for millennia.

Aesculapian Snake (Zamenis longissimus) © Matt Wilson

The Regent’s Canal population has been much studied (Langton et al., 2011; Atkins, 2020). The initial population was accidentally (or deliberately) released from a research facility near the canal in the 1980s. The snakes have bred successfully, reaching a peak population of around 40 in 2013, possibly declining a little since then.

The Colwyn Bay population derives from an escape in the 1970s from the Welsh Mountain Zoo. Successful breeding has again occurred, with an estimated population of 70 adults by 2022, all still in the Colwyn Bay area. Major et al. (2025) have reported on an extensive study of the snakes’ movements and habitat preferences. They captured 13 males and 8 females, surgically inserted radio transmitters then released the snakes at the point of capture (capture was not easy, as the snakes are hard to find: the authors estimate an average hunt of 8 hours per snake). Daily movements were on average 52 metres for males; males showed some preference for buildings as habitat, while females preferred woodland. Snakes fed on small mammals and birds, but were in turn predated by larger mammals and in one case, a buzzard. Mortality during the study was quite high, including on roads.

Unlike the Brown Tree Snake on Guam and the Horseshoe Whip Snake on Ibiza, there is no evidence that the Aesculapian Snake poses any danger to the long term survival of our native wild species, but the UK is not a small island relatively free of predators.

Click to see references

References

Atkins, W. (2020). Observations on a feral population of Aesculapian snakes. The London Naturalist 99, 77-112.

Casbas, G. et al.(2026). Swimming snakes wipe out endemic lizards from Mediterranean islets. Ecology 107, e70373.

Langton, T. et al. (2011). On the distribution, ecology and management of non-native reptiles and amphibians in the London area: 1- Distribution and predator/prey impacts. The London Naturalist 90, 83-155.

Major, T. et al. (2025). A reliance on human habitats is key to the success of an introduced predatory reptile. PLoS ONE 20 (2), e0310352.

Wiles et al. (2003). Impacts of the Brown Tree Snake: patterns of decline and species persistence in Guam’s avifauna. Conservation Biology 17, 1350-1360.

What our animals are doing this month

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Toadlet Time: A Summer Spectacle

July is a wonderful month to witness one of nature’s most fascinating transformations as common toad tadpoles complete their metamorphosis and emerge as tiny toadlets.

The journey begins in spring, when toads lay strings of eggs in ponds. These eggs typically hatch within two to four weeks, releasing tadpoles into the water. Over the following weeks, the tadpoles feed on algae and other plant matter, gradually growing and developing. It usually takes around 16 weeks for them to reach the stage where their legs begin to form, although this can vary depending on factors such as water temperature, food availability and the number of tadpoles sharing the pond.

As metamorphosis progresses, remarkable changes take place. The developing toadlets grow legs, absorb their tails and develop lungs, allowing them to breathe air and prepare for life on land. Once these changes are complete, they leave the safety of the pond and venture out into the surrounding habitat.

If you live near a breeding pond, you may have been lucky enough to witness a toadlet emergence in previous years. Hundreds, or even thousands, of tiny toads can leave the water over a short period, creating an unforgettable wildlife spectacle. Although they have left the pond behind, these young toads usually stay close to their birthplace throughout the summer and early autumn, spending their time feeding and growing before the winter months arrive.

Toadlet emergences are often most noticeable after periods of rainfall, when damp conditions make it easier and safer for them to travel. Keep an eye out at any time of day. You never know when you might spot these miniature amphibians beginning their life on land!

Travelling Toadlets Project:

You can also help us this summer by reporting your toadlet sightings. ‘Travelling Toadlets’ is a collaborative project funded by the Natural England Species Recovery Programme and aims to find out more about migrating common toads in the UK. This is in partnership with ARG UK, The UK Centre for Ecology and Hydrology, University of Chester and Froglife.

Find out more and report your sightings here.

Long-term pond condition research underway

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By Emily Seccombe, PhD student at the University of Reading, in partnership with Froglife

Evidence-based pond conservation

Within conservation practice, there is an increasing movement towards ensuring decision-making is evidence-based, to make best use of limited resources (Christie et al., 2021; Habel et al., 2013). Froglife is one of Conservation Evidence’s ‘Evidence Champions’, meaning that it is committed to using scientific evidence in its work, to test and publish research on conservation interventions used, and to generate evidence-based guidance.

Ponds are considered a “straight-forward” intervention for amphibian conservation (Moor et al., 2024) but how well do we understand how ponds created for amphibian conservation provide benefits in the long-term? For how long will created ponds provide amphibian breeding habitat, in different scenarios? What proportion of ponds are likely to fail to hold water or be filled in?

Historically, ponds have had less research effort than other freshwater ecosystems (Biggs et al., 2005), though this has been improving. A number of studies in the academic and grey literature provide assessment of pond creation for amphibian conservation, which can provide some insights for conservation interventions…

What do we know about how created ponds benefit amphibians?

Evidence shows that new ponds can support amphibian populations in the first few years after their creation. For example, Barry et al. (2008), monitored 22 constructed ponds in the USA, finding amphibians breeding in 11 ponds after one year and 14 ponds after two years. A study in Estonia by Rannap et al. (2009) looked at 208 created ponds and 22 restored ponds within 3 years of the works, and found the number of amphibian species was higher in these ponds than in local comparison ponds. Ruhí et al. (2012) found that over half of the local amphibian species used two newly created Mediterranean temporary ponds for breeding within the first hydroperiod (3 of 5 species and 6 of 11 species, at the two ponds respectively), which further increased by the second hydroperiod (to 4 of 5 species and 8 of 11 species).  

Image 1. Pond creation in progress, during Froglife’s Sheffield Living Waters project, at Woodhouse Washlands, now managed by Sheffield and Rotherham Wildlife Trust, (photo credit: Froglife). New ponds can provide habitat for amphibians within the first few years of creation.

Beyond the amphibian conservation focus, ponds have received increasing research attention in recent decades regarding their roles in providing ecosystem services (Cuenca-Cambronero et al., 2023; Hill et al., 2018). Ponds that may not support large amphibian populations may still be contributing to ecosystem health (Hill et al., 2018), climate resilience (Bartrons et al., 2024) and human well-being and health (Arnberger et al., 2017; Benejam et al., 2026).

But what do we know about how and where to create these ponds to provide the most benefit to amphibians? Much of the evidence (e.g. Baker & Halliday, 1999; Hazell et al., 2004) used to inform pond creation decisions is based on research on other pond types (such as historic natural ponds, agricultural ponds or sustainable urban drainage ponds) rather than from ponds created as part of conservation efforts. Such research shows us that the presence of fish is in conflict with amphibian breeding success (as demonstrated by numerous studies including Denoël & Ficetola, 2008, Hamer & Parris, 2011 and Skei et al., 2006) and that proximity to other ponds are a key predictor of a new pond hosting amphibians (Baker & Halliday, 1999). However, this inference from ponds created for different purposes may not always be helpful for conservation: they may be created in different places, under different management plans, and with different surrounding habitat than purpose-built conservation ponds.
Image 2: Male palmate newt in pond shallows (left) and an emergent froglet (right). Predictors of amphibian presence in new ponds include absence of fish and proximity to other ponds. Both photos taken at ponds created through Froglife’s Sheffield Living Waters project, copyright Emily Seccombe.

 

Short-term vs long-term pond research

The examples of studies on the amphibian benefits of pond creation given earlier share a short temporal scale: monitoring amphibians in ponds over 2 years since creation, 3 years since creation and 2 years since creation respectively (Barry et al., 2008; Rannap et al., 2009; Ruhí et al., 2012). The short-term bias of much of the literature may obscure the larger picture. Ponds which are quickly colonised by amphibians may not support long-term breeding success, or they may suffer from issues, such as pollution or invasive plant species, in later years. One of the few published studies that did undertake long-term monitoring of ponds in the UK found that new ponds had limited success: ponds had a high turnover, and were often lost or in poor condition by end of the monitoring period (Beebee, 1997). For how long do created ponds continue to benefit amphibians, and under what conditions? Improving our understanding of this could help to inform pond creation in the future.

Of the 30 studies listed in the Conservation Evidence database as providing evidence on pond creation as an amphibian conservation intervention, 9 studies look at ponds 10 or more years since creation, compared to 12 studies that look at ponds created less than 5 years prior (the remaining 9 looked at ponds of intermediate ages, don’t specify the ages of the ponds studied, or present a mix of evidence). Of the 9 studies that look at pond creation in the long-term, only one uses data from the last 20 years (Berroneau et al., 2010).

Challenges to pond creation in the 21st century

The key study by Beebee (1997) noted above, and several of other informative longer-term studies (such as (Banks et al., 1993; Petranka et al., 2003; L. R. Williams, 2005), are over 20 years old. Whilst many factors of pond ecology remain relevant over this time frame, these studies may not explore the climate-related challenges faced when creating ponds today, such as the increased frequency of hot, dry summers, as seen in the UK (Dunford & Berry, 2012). Increased temperatures due to climate change reduce saturated oxygen levels in ponds (Ali et al., 2016). Furthermore, increased summer temperatures cause common toads to emerge in poorer condition, which may reduce their winter survival chances (Reading & Jofré, 2023). In recent research, pond creation and restoration practitioners were reported as perceiving climate change as the highest threat to their pond projects’ success (de Necker et al., 2025). In light of these climatic threats, new research to understand whether created ponds hold sufficient depths of water throughout the breeding season is needed.
Image 3: Two examples of ponds with water levels that drop drastically during the amphibian breeding season, leaving limited space for larvae to develop. Both photos taken at ponds created through Froglife’s Sheffield Living Waters project, copyright Emily Seccombe.

 

Froglife and University of Reading research on conservation impacts

To tackle this research gap, Froglife are supporting a University of Reading PhD project exploring the temporal and spatial impacts of conservation actions on British reptiles and amphibians, funded by a CROCUS NERC Doctoral Landscape Award (Training Grant Reference: UKRI1349). A key part of this research is to look at ponds created by Froglife over the last 15 years and assess their current amphibian breeding potential.

In the first year of the study, 56 ponds in Sheffield were surveyed in four repeated visits in Spring 2026. These ponds were created by Froglife’s Sheffield Living Waters projects, which ran between 2013 and 2019.

Data was collected to understand what proportion currently provide suitable amphibian breeding habitat and what factors affect this, such as water quality, invertebrate diversity, site management and vegetation levels. Surveys were carried out following standardised protocols used by the Countryside Survey (Williams et al., 2010), the PondNet pond habitat survey (Freshwater Habitats Trust, 2015) and the National Amphibian Survey (Amphibian and Reptile Conservation Trust, 2021). Amphibian surveys between March and June were used to assess breeding success. At each pond, water levels and temperature are recorded, with the aim of better understanding whether high water temperatures and reduced hydroperiods are a concern in these created ponds.

Additionally, desk-based research will be used to gather existing amphibian records at these sites, and to assess geographical data, such as urban density, around each of the study’s ponds. Findings of this research will be shared by Froglife following further analysis. By investigating how these ponds have fared in the long-term, including identifying key challenges to pond condition, we hope to be able to better inform pond creation efforts going forward.
Image 4: Assessment of a pond that has filled with vegetation (left) and pond dipping at a created pond (right). The current research by the University of Reading and Froglife hopes this fieldwork will provide insight into how purpose-built amphibian conservation ponds fare in the long-term. Both photos taken at ponds created through Froglife’s Sheffield Living Waters project, copyright Emily Seccombe.

Contact Emily Seccombe: e.r.seccombe@pgr.reading.ac.uk

Click here for references

Ali, S., Mishra, P. K., Islam, A., & Alam, N. M. (2016). Simulation of Water Temperature in a Small Pond Using Parametric Statistical Models: Implications of Climate Warming. Journal of Environmental Engineering, 142(3). https://doi.org/10.1061/(asce)ee.1943-7870.0001050

Amphibian and Reptile Conservation Trust. (2021). National Amphibian Survey Protocol: V2021.1.

Arnberger, A., Allex, B., Eder, R., Ebenberger, M., Wanka, A., Kolland, F., Wallner, P., & Hutter, H. P. (2017). Elderly resident’s uses of and preferences for urban green spaces during heat periods. Urban Forestry and Urban Greening, 21, 102–115. https://doi.org/10.1016/j.ufug.2016.11.012

Baker, J. M. R., & Halliday, T. (1999). AMPHIBIAN COLONIZATION OF NEW PONDS IN AN AGRICULTURAL LANDSCAPE. HERPETOLOGICAL JOURNAL, 9, 55–63.

Banks, B., Beebee, T. J. C., & Denton, J. S. (1993). Long-term management of a natterjack toad (Bufo calamita) population in southern Britain. Amphibia-Reptilia, 14, 155–168.

Barry, D. S., Pauley, T. K., & Maerz, J. C. (2008). Amphibian use of man-made pools on clear-cuts in the Allegheny Mountains of West Virginia, USA. Applied Herpetology, (5), 121–128. www.brill.nl/ah

Bartrons, M., Trochine, C., Blicharska, M., Oertli, B., Lago, M., & Brucet, S. (2024). Unlocking the potential of ponds and pondscapes as nature-based solutions for climate resilience and beyond: Hundred evidences. Journal of Environmental Management, 359. https://doi.org/10.1016/j.jenvman.2024.120992

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Become a Dragon Finder Detective: Report Non-Native Species

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Written by Dr Andrew Smart, Head of Science and Research

Have you seen any of these recently?

 

These are the more frequently recorded invasive, non-native species of reptile and amphibian found in the UK. 

At Froglife we are trying to get an idea of the distribution, range expansion and colonisation of these non-native species which are, for the most part, restricted in pockets where conditions suit them. 

Some species, such as the alpine newt and marsh frog (the top two non-native species on our records database), are increasing their range because of accidental movement of eggs or tadpoles. There are risks to our native species as these non-natives expand their range; the possibility of disease spread (some animals are potential vectors for chytrid fungus); some are potential predators on eggs and tadpoles; some are potential sources of genetic change through hybridisation.

Our highest recorded non-native reptile is the common wall lizard. Records from our Dragon Finder Citizen Scientists helped us locate a new population of this species in Kent Johanson & Tse-Leon (2022).

This week, 22 – 28th June 2026, is Invasive Species week and we’d like to ask you to look out for non-native species not just this week, but going forward. Please send in your records via our free Dragon Finder App.  It’s easy to upload to your phone and provides information on all the species of reptile and amphibian you are likely to find in the UK (native and non-native).

We share all our species location data with the NBN Atlas each year so that everyone can see where our species are found in their local area.

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