Inspired by Nature: A Poem of Return
Froglife’s Communications & Fundraising Officer, Ashlea Mawby, felt inspired by the work she does here at Froglife and wrote this poem.
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Hot Weather Warning – Amphibians & Reptiles
Hot Weather Warning – Amphibians & Reptiles
Many people are enjoying the sizzling heat and sun that has now arrived in the UK. It is important to note that these extreme temperatures pose a risk to some of our UK wildlife. Our UK amphibian species struggle in high temperatures, particularly the tiny froglets and toadlets that are just emerging from their tadpole phase.
The most obvious and useful way to help these animals is to #BuildAPond, giving these animals and other wildlife ready access to water, for drinking and bathing. But building a pond doesn’t have to be a big nor expensive endeavour, and small ponds (e.g. bucket-sized) can be just as effective. Read more about building a pond with our FREE online guide Just Add Water check out our activity sheets in our Idea Zone.
In these heat extremes, a quick 2-minute job of putting out a small container or dish filled with fresh water will also help wildlife in your garden. If it’s a deep dish, don’t forget to add in a ramp or some stones to allow any animals that may fall in to have a way to climb out. It is best to fill with water from a water butt rather than the tap, if you have one. However, if tap water is your only source, remember to leave it standing in a bucket for at least 24 hours so any chemicals can dissipate and the temperature can balance out.
Frogs, toads, birds and hedgehogs all eat small invertebrates like worms, which in this hot weather burrow deeper down into the dry soils. With this in mind, it is important to keep plants and soils damp to allow these predators to access their vital food source.
In addition to adding water into your outdoor space, keeping areas wild and sheltered can potentially save amphibian lives. Rockeries and log piles both provide shade to amphibians in the garden, where often the soil beneath will remain damp and the temperature much cooler that the outside.
Even reptiles, like common lizards and grass snakes that can often be found basking in the sun, need shaded areas for relief from high temperatures. So log piles and rockeries are equally important for these animals to escape from the sun’s rays.
Croaking Science: eDNA for detecting great crested newts – a replacement for traditional survey techniques?
eDNA for detecting great crested newts – a replacement for traditional survey techniques?
Environmental DNA, or eDNA, is released by most organisms as they occupy different habitats. Each species has a unique type of eDNA which can be recognised through laboratory analysis. This provides a novel tool for detecting species within the environment. Sources of eDNA may originate from sloughed skin or hair, eggs, faeces and saliva (Figure 1). Within aquatic habitats, most organisms release eDNA into the surrounding water. An increasing number of methods are now available for detecting the eDNA of a range of aquatic organisms including fish, damselfly nymphs, crustaceans and amphibians. In recent years, techniques have advanced to allow the detection of eDNA of great crested newts from their breeding ponds. This has proved particularly useful for ecologists and voluntary surveyors who need to determine the presence or absence of great crested newts for the purposes of conservation and mitigation. The eDNA technique, though expensive, is usually highly reliable and effective at detecting great crested newts. Research carried out by Biggs et al. (2015) of 35 ponds in Hampshire and Wales showed that eDNA could successfully detect the presence of great crested newts in 99.3% of ponds. This was significantly higher than the success rate of more traditional survey techniques.
Traditional survey techniques for detecting great crested newts such as egg-searching, night torching and bottle trapping are labour intensive, carry certain risks (e.g. potential suffocation of newts in traps) and are not always highly effective. Biggs et al. (2015) found that bottle trapping detected great crested newt presence in 76% of ponds and egg searching in only 44% of visits. Using traditional survey techniques, Natural England advice recommends four visits to a breeding pond in the newt breeding season (mid-March to mid-June) using a minimum of three traditional survey techniques (Natural England, 2015) (Figure 2). The eDNA technique, by contrast, can detect great crested newts on just one visit with minimal disturbance to breeding ponds (Biggs et al., 2015). Therefore, should eDNA replace traditional surveys techniques to detect great crested newts? In this article we highlight the relative advantages of disadvantages of eDNA and point out the limitations that ecologists and voluntary surveyors need to be aware of when using the technique.
One of the major advantages of eDNA is the relative ease that samples can be taken from a pond and the subsequent reduction in labour costs. For example, one fieldworker may be able to take samples for analysis within one survey visit, compared to the multiple sessions required using traditional survey techniques. However, the analysis costs associated with eDNA may be significant, especially if carrying out many samples. A second major advantage of eDNA is its overall reliability compared to other traditional methods. However, a range of studies have found variations in the success of eDNA, ranging from 60% to 99% (Buxton et al., 2017a).
Despite is apparent reliability and success in detecting great crested newts, there are a number of limitations of using eDNA to survey ponds. Six of the main limitations are outlined below:
- Estimation of abundance: the level of eDNA detected from samples taken from a pond does not correlate well with the number of newts in the pond. Biggs et al. (2015) found that at low levels of detection, eDNA may reflect the number of newts but at higher levels, there was only a weak, non-significant correlation. Therefore, it is not currently possible to use eDNA to estimate the population size or relative abundance of great crested newts using ponds. Traditional survey techniques, such as night torching or bottle trapping, may provide an estimate of relative abundance. For example, if 120 newts are captured in bottle traps, this shows that at least this number of newts were present in the pond on this survey occasion.
- Life stages: eDNA only records presence, or recent occupancy, of ponds by newts; it does not show which life stages are present e.g. adults, eggs or larvae, or when they were last in the pond (Rees et al., 2014a). Traditional survey techniques can identify actual animals which is useful for looking at life stage, sex ratio and potentially the body condition of individuals. Also, traditional techniques can record other species of newt which are present in ponds e.g. smooth or palmate newts, which is often important for survey records and provides an indication of the species diversity within a pond.
- Breeding or non-breeding? It is often useful to determine whether great crested newts are breeding within a pond as this may show persistence of a viable, long-term population. However, the eDNA techniques is not able to detect if newts are laying eggs within a pond; it can only determine if they are present, or have recently been present. The traditional survey technique of egg-searching is able to detect the presence of breeding females demonstrating the value in using this technique.
- False absences: a false absence is when a particular technique fails to determine the presence of the species, even though it is present. Although the level of false absences using eDNA was very low in one study carried out by Biggs et al. (2015), this was only carried out on 35 ponds in two counties in the UK. Similar research carried out by Rees et al. (2014) on 38 ponds showed that eDNA had a lower success rate of 89% in detecting great crested newts in ponds. Given the number of false absences in this study Rees et al. (2014) conclude: “Species detection by eDNA and field work is likely to be imperfect and may lead to an underestimation of the distribution of a species especially in the case of rare or threatened species”. False absences may come from a number of sources and are more likely to be a problem when they operate together (Biggs et al., 2015). Common sources of false absences include:
- when there are very few newts in a pond and the water samples fail to collect any eDNA;
- in ponds where surveyors can only access a small proportion of the pond perimeter due to logistical issues;
- at sites which have a very large area of shallow water, which prevents surveyors from reaching the deeper edges often favoured by newts (Biggs et al., 2015) (Figure 3).
- False positives: detecting newts when they are not present is less commonly a problem with eDNA for great crested newts but can occur when there is contamination within the samples collected (Thomsen & Willerslev, 2015). Potential sources of contamination include: excrement from animals that prey on great crested newts; the eDNA of dead great crested newts being carried to the pond by other species (e.g. birds); or unsterilized equipment contaminating samples (Bohmann et al., 2014).
- Reduction or loss of DNA in the water: There are three potential processes that can result in the loss or reduction in the quantity of DNA from within samples: inhibition, degradation, and binding to sediments. This can lead to increases in the likelihood of false absences occurring as less eDNA may be available to detect in analysis.
- Inhibition: eDNA inhibition occurs when factors in the environment, such as decaying organic matter, interfere with the laboratory analysis, resulting in a failure to detect the eDNA (Buxton et al., 2017a).
- Degradation: once eDNA is released into the environment it starts to decay and this rate depends on a range of factors such as UV radiation, temperature and microbes which occur in the pond (Buxton et al., 2017; Rees et al., 2017). Currently, our understanding of how quickly eDNA degrades under different conditions is limited (Rees et al., 2014a). This is of importance since if eDNA degrades faster in some ponds than others, this may limit the likely time window when surveys can be carried out. Although research has shown that eDNA may be present in ponds in all months of the year (Rees et al., 2017), the realistic time frame for detecting adults is March to the end of June (Rees et al., 2017) which is the same as for traditional survey techniques. However, if ponds contain breeding adults and subsequent larvae, these may be detected in ponds up until the end of August (Buxton et al., 2017).
- Binding to sediments: research has also demonstrated that eDNA will bind to certain sediments in ponds. Buxton et al. (2017a) have shown that eDNA binds more effectively to clay and organic soils when compared to sand. This has important consequences for surveying since the eDNA will disappear much more quickly in ponds with clay sediments. This means that if great crested newts are present in two ponds, one with a clay sediment and one with a sand sediment, the available time frame for surveying may be shorter in the pond with clay lining. A late survey carried out may result in a false absence record in the pond with clay sediment, even though the newts had recently been present. Given the variation in occurrence of eDNA in water samples, the potential for false absences needs to be fully understood before using eDNA as a survey tool and it is important to realise that eDNA research is still an evolving discipline (Buxton et al., 2017a).
Overall, although using eDNA to detect the presence of great crested newts is highly effective and usually reliable, ecologists and surveyors must be aware of the potential limitations when carrying out surveys. Therefore, caution should be taken when analysing the results from eDNA; ecologists and surveyors should consider eDNA as an additional technique to complement traditional survey methods, rather than being viewed as replacing existing techniques. We conclude this article with a statement by Rees at al. (2014a): “Environmental DNA methodologies should not be used to replace or disregard the knowledge and expertise of experienced field ecologists and taxon specialists, but should become an important tool to enhance limited conservation resources”.
References
Biggs, J., Ewald, N., Valentini, A., Gaboriaud, C., Dejean, T., Griffiths, R.A., Foster, J., Wilkinson, J.W., Arnell, A., Brotherton, P., Williams, P. & Dunn, F. (2015) Using eDNA to develop a national citizen science-based monitoring programme for the great crested newt (Triturus cristatus). Biological Conservation, 183: 19–28.
Buxton, A.S., Groombridge, J.J., Zakaria, N.B. & Griffiths, R.A. (2017) Seasonal variation in environmental DNA in relation to population size and environmental factors. Science Reports, 7: 46294; doi: 10.1038/srep46294.
Buxton, A.S., Groombridge, J.J. & Griffiths, R.A. (2017a) Is the detection of aquatic environmental DNA influenced by substrate type? PLoS ONE, 12 (8): e0183371.
Bohmann, K., Evans, A., Thomas, M., Gilbert, P., Carvalho, R., Creer, S., Knapp, M., Yu, D.W. & de Bruyn, M. (2014) Environmental DNA for wildlife biology and biodiversity monitoring. Trends in Ecology & Evolution, 29 (6): 358-367.
Natural England (2015) Great crested newts: surveys and mitigation for development projects. https://www.gov.uk/guidance/great-crested-newts-surveys-and-mitigation-for-development-projects#when-to-survey. Accessed 20th June 2018.
Rees, H.C., Bishop, K., Middleditch, D.J., Patmore, J.R.M., Maddison, B.C. & Gough, K.C. (2014) The application of eDNA for monitoring of the Great Crested Newt in the UK. Ecology and Evolution, 4 (21): 4023–4032.
Rees, H.C., Maddison, B.C., Middleditch, D.J., Patmore, J.R.M. & Gough, K.C. (2014a) The detection of aquatic animal species using environmental DNA – a review of eDNA as a survey tool in ecology. Journal of Applied Ecology, 51: 1450–1459.
Rees, H.C., Baker, C.A., Gardner, D.S., Maddison, B.C. & Gough, K. (2017) The detection of great crested newts year round via environmental DNA analysis. BMC Res Notes, 10: 327. DOI 10.1186/s13104-017-2657-y.
Thomsen, P.F. & Willerslev, E. (2015) Environmental DNA – An emerging tool in conservation for monitoring past and present biodiversity. Biological Conservation, 183: 4–18.
Croaking Science: Kin Recognition
Kin recognition – when recognising relatives is important
During the spring in temperate countries tadpoles of frogs and toads often develop in a range of water bodies from small ponds to lakes. Swimming around in the open water, tadpoles are highly vulnerable to predation so in many species such as the common toad (Bufo bufo), tadpoles swim in large groups or shoals (Figure 1). By living in groups the tadpoles gain advantages such as decreased risks of predation and increased access to food. However, there are costs to group living such as an increase in the risk of transmitting infectious disease and intraspecific competition. Research has shown that tadpoles further increase the benefits of group living by associating with relatives, or close kin. If forming shoals reduces the risk of predation, then swimming with relatives who possess similar genes will increase the chances that these genes will survive to the next generation. The exact mechanism of kin recognition in anuran tadpoles is not clear but studies suggest that frog and toad tadpoles recognise each other through chemical cues (Eluvathingal et al., 2009). The persistent dense swimming shoals of tadpoles of many amphibians from the genera Rana and Bufo (e.g. wood frog (Rana sylvatica); common toad (Bufo bufo); and boreal toad (Bufo boreas)) have been shown to consist primarily of associations of closely related kin (Blaustein & Waldman, 1982). However, in the red-legged frog (Rana aurora), Schneider’s toad (Duttaphrynus scaber) and Günther’s golden-backed frog (Indosylvirana temporalis), tadpoles only exhibit kin recognition early in their development when they form dense shoals. As they mature, tadpoles disperse and kin recognition drops (Rajput et al., 2014). During late development the risks of pond desiccation are high and individual tadpoles seek isolated patches of water. Under these conditions the risks of suffocation through desiccating water is higher than the benefits of associating with relatives. Further to this, recent research has shown that the persistence of associating with kin varies considerably even within a single species. For example, larvae of the wood frog (Rana sylvatica) from North America exhibits kin recognition and individuals often choose to swim with relatives. However, Halverston et al. (2006) have shown that the level and occurrence of swimming with relatives is not consistent but depends on a range of factors including levels of competition, predation and parasitism. Tadpoles from two adjacent ponds exhibited different levels of association with kin due to localised differences in these factors (Halverston et al., 2006). This demonstrates that associating and swimming with relatives only occurs under certain environmental conditions and groups of tadpoles may show variations in their degree of kin association.
Many amphibians within temperate zones are herbivorous, however there are a number of tropical species of tadpole which are carnivorous. This provides the opportunity for cannibalism to evolve where larger tadpoles may predate smaller ones within the same species. In these species it may be advantageous for tadpoles to recognise kin to avoid potential predation on relatives who carry the same genes. Research has shown that cannibalism generally occurs when the nutritional benefits gained from eating relatives outweigh the disadvantages such as risks of injury, transmitting infectious diseases and losing potential members of the same species who carry similar genes. As a result, cannibalism has evolved in some carnivorous amphibian larval species, but not others, depending on the environmental conditions and the relative advantages and disadvantages of consuming close kin.
Many tropical frogs in the genus Dendrobates lay their eggs in terrestrial habitats that are then transported by males to small water-filled water bodies formed in the axils of tree leaves (phytotelmata). Females of the poison dart frog Dendrobates auratus only lays a few eggs per year, so the number of tadpoles developing within any given water body is low. In some species of Dendrobates frogs, the female lays non-fertile eggs into the water to feed the tadpoles. However, female D. auratus does not perform this behaviour so the tadpoles rely completely on external food sources e.g. fallen insects, for survival. Starvation within such small water bodies is very high and therefore cannibalism has evolved to allow some of the tadpoles to survive. In this species the larger tadpoles predate the smaller ones which provides additional nutrition which is crucial for survival. However, male D. auratus may bring tadpoles from a number of clutches so there is also the potential for kin recognition i.e. larger tadpoles may choose to consume non-relatives over relatives since the latter may share the same genes. However, experiments carried out by Gray et al. (2009) suggest this is not the case and that larger tadpoles indiscriminately predate kin from non-kin. The authors hypothesise that since food sources are so scarce for developing tadpoles then the benefits of individual survival outweigh the costs of losing genetic relatives.
Additional research by Poelman & Dicke (2007) has shown that in the poison dart frog Ranitomeya ventrimaculata, females exhibit a plasticity in where she lays her eggs, which depends on environmental conditions (Figure 2). In this species, like D. auratus, tadpoles are highly cannibalistic, consuming both kin and non-kin. At the beginning of the breeding season, when water-filled phytotelmata do not contain many tadpoles, the female will spread her eggs widely amongst different water bodies, avoiding those which already contain a tadpole. This reduces the chances that her eggs will get consumed by another tadpole (which may or may not be her own). However, nearer to the end of the breeding season, the female changes behaviour and actively starts laying more eggs in phytotelmata which already contain large tadpoles. Poelman & Dicke (2009) hypothesise that this is because at the end of the breeding season there are few free phytotelmata left and by provisioning those that already contain tadpoles with fertilised eggs, she is providing food to the tadpoles which may be her own. This sacrifice of eggs will indirectly improve the survival of her existing tadpoles, the eggs of which she laid early in the breeding season. This plasticity in behavioural response allows a greater number of tadpoles to survive when the risk of desiccation of water bodies is high.
The green and golden bell frog (Litoria aurea) was once a common species widely distributed in south eastern Australia (Figure 3). It has also been introduced into New Zealand and surrounding islands. However, the extreme sensitivity of these species to the infectious chytrid fungus has been the major cause of the species’ decline in its native range and the species is currently restricted to small isolated populations. The tadpoles form groups where individuals gain protection from predators, increased foraging efficiency and better growth. Associating with relatives is advantageous since individuals would be indirectly protecting those carrying similar genes. Pizzatto et al. (2016) examined the behaviour of tadpoles of the green and golden bell frog in relation to kin recognition. The authors found that in the bell frog L. aurea tadpoles did indeed distinguish kin from non-kin and thus formed shoals containing mainly relatives. The authors suggest the advantages to this species include increased growth and increased resistance to disease since related members are likely to carry the same disease resistance genes.
References
Blaustein, A.R. & Waldman, B. (1982) Kin recognition in anuran amphibians. Animal Behaviour, 44: 207 -221.
Eluvathingal, L.M., Shanbhag, B.A. & Saidapur, S.K. (2009) Association preference and mechanism of kin recognition in tadpoles of the toad Bufo melanostictus. Journal of Bioscience, 34 (3): 435–444.
Gray, H.M., Summers, K. & Ibáñez, R.D. (2009) Kin discrimination in cannibalistic tadpoles of the Green Poison Frog, Dendrobates auratus (Anura: Dendrobatidae). Phyllomedusa, 81 (1): 41-50.
Halverson, M.A., Skelly, D.K. & Caccone, A. (2006) Kin distribution of amphibian larvae in the wild. Molecular Ecology, 15: 1139–1145.
Poelman, E.H. & Dicke, M. (2007) Offering offspring as food to cannibals: oviposition strategies of Amazonian poison frogs (Dendrobates ventrimaculatus). Evolution and Ecology, 21: 215–227.
Pizzatto, L., Stockwell, M., Clulow, S., Clulow, J. & Mahony, M. (2016) How to form a group: effects of heterospecifics, kinship and familiarity in the grouping preference of green and golden bell frog tadpoles. Journal of Herpetology, 26: 157–164.
Rajput, A.P., Saidapur, S.K. & Shanbhag, B.A. (2014) Kin discrimination in tadpoles of Hylarana
temporalis (Anura: Ranidae) and Sphaerotheca breviceps (Anura: Dicroglossidae): influence of hydroperiod and social habits. Phyllomedusa, 13 (2): 119–131.
Croaking Science: Mutualism- novel interactions between amphibians and other species
Mutualism: novel interactions between amphibians and other species
Mutualism is widespread within the animal kingdom and involves the close association between two organisms of different species in which both benefit. Within the Amphibia, there are a number of interesting and novel mutualistic interactions. These range from symbiosis with algae to interactions with predatory spiders and living with water buffalo. Our understanding of the range and extent of mutualistic interactions within amphibians remains relatively poorly understood and here we review some recent discoveries.
The mutualistic symbiosis between algae and embryos of the Spotted Salamander (Ambystoma maculatum) from North America was first reported more than 120 years ago (Figure 1). In this relationship, algae live inside the developing embryos and appear to provide many benefits to the salamanders including: earlier hatching, decreased mortality and reaching a larger size at hatching (Kerney et al., 2011). The algae are thought to gain through feeding on the nitrogenous wastes released by the embryos. Research by Kerney et al. (2011) found that this relationship is closer than originally thought. Through imaging and genetic experimentation, the researchers found that the algae actually invade the salamander tissues during embryo development and live inside the cells of the salamanders for a period of several weeks. At the end of larval development algal cell death occurrs in the majority of salamander cells. However, the researchers found genetic material of the algae in the reproductive tracts of adults, suggesting that the algae remains present and is transferred from one generation to another through the reproductive tract of the adults. This research raises the possibility of transfer of DNA between species and provides evidence of highly close relationships between two very different organisms.
Mutualism between larval amphibians and algae has been reported from other species. The tadpoles of the Dwarf American Toad (Bufo americanus charlesmithi) live in warm, shallow and temporary ponds which receive extended periods of sunlight (Figure 2). It has previously been observed that the tadpoles develop a bright green colouration during their development in these conditions. Tumlison & Trauth (2006) conducted a series of experiments and found that the green glow was the result of a symbiotic algae (Chlorogonium) living on the skin of the tadpoles. The tadpoles benefit through receiving oxygen from the algae who photosynthesise in the sunlight. Shallow, temporary ponds experience severe oxygen depletion during periods of high sunlight and warmth so as a result of obtaining oxygen from the algae, the tadpoles are able to survive longer in the ponds and reach a larger size before metamorphosis. In return, the algae received carbon dioxide from the tadpoles during respiration which aids in their growth.
The family of microhylid frogs from Sri Lanka comprises four genera and 10 species. Several of these species have restricted distributions and occur only in the Kanneliya Forest Reserve. The ecology of many of these microhylid frogs is poorly understood but adults appear to breed in tree holes. Karunarathna & Amarasinghe (2009) found a novel mutualistic interaction between the microhylid frog Uperodon nagaoi and two species of tarantula spider (Poecilotheria species). Both amphibian and tarantula species have been observed to share tree holes and it appears that both species protect each other’s eggs. The eggs of both the amphibian and tarantula are attacked by species of ants, mantids and other spider species. On several occasions Karunarathna & Amarasinghe (2009) recorded the tarantula attacking mantids that were feeding on U. nagaoi eggs. Similarly, individual U. nagaoi were observed predating ants that were feeding on the eggs of the tarantula. In addition, the tadpoles of U. nagaoi appeared to benefit from the remains of predated insects falling into water where they were developing.
Many species of herbivorous vertebrate harbour large populations of nematode worms in their guts. Herbivorous tadpoles are no exception with several thousand species of nematode being recorded from larvae. Several researchers have proposed that some species of nematodes may be mutualistic and provide benefits to their host. This appears to be the case with American Bullfrog (Lithobates catesbeiana) tadpoles which harbours the nematode (Gyrinicola batrachiensis) during its larval stage. Research by Pryor & Bjorndal (2005) found that America Bullfrog tadpoles infected with this nematode increased their rate of development by approximately 16 days, allowing the tadpoles to metamorphose earlier than tadpoles without the nematodes. This has many benefits as this promotes higher survival and subsequent reproductive success of the newly metamorphosed froglets. There could be two main reasons to explain this increase in development. First, the increase in gut size to allow the nematode to live may result in increased food intake and absorption by the tadpole. Second, the nematode increases rate of food fermentation in the gut, which allows the tadpole to absorb more food. The results of this study highlights that some gastrointestinal nematodes inhabiting the gut regions of other herbivores may have a beneficial effect on digestion and nutrition in those hosts.
Figure 3. Anatonian Water Buffalo have a novel mutualistic interaction with Marsh Frogs in Turkey.
A final form of novel mutualism has been observed between Marsh Frogs (Pelophylax ridibundus) and the Anatolian Water Buffaloes (Bubalus bubalis) in Turkey (Figure 3). Zduniak et al. (2017) reported a unique behaviour in the frogs where individuals climbed up the fur and onto the backs and heads of the buffaloes where they appeared to be predating flies. Up to 31 frogs were observed feeding on a single buffalo at any one time (Zduniak et al., 2017). It appears that both species benefit from this interaction since the frogs gain food and the buffalo has flies removed which may cause irritation. This appears to be the first record of such interaction between these two species and highlights that novel mutualistic interactions may occur more widely between amphibians and other species.
References
Tumlison, R. & Trauth, S.E. (2006) A novel facultative mutualistic relationship between bufonid tadpoles and flagellated green algae. Herpetological Conservation and Biology, 1 (1): 51-55.
Karunarathna, D.M.S.S. & Amarasinghe, A.A.T. (2009) Mutualism in Ramanella nagaoi Manamendra-Arachchi & Pethiyagoda, 2001 (Amphibia: Microhylidae) and Poecilotheriam species (Arachnida: Thereposidae) from Sri Lanka. Taprobanica, 1 (1): 16-19.
Kerney, R., Kim, E., Hangarter, R.P., Heiss, A.A., Bishop, C.D. & Hall, B.K. (2011) Intracellular invasion of green algae in a salamander host. PNAS, 108 (16): 6497-6502.
Pryor, G.S. & Bjorndal, K.A. (2005) Effects of the nematode Gyrinicola batrachiensis on development, gut morphology, and fermentation in bullfrog tadpoles (Rana catesbeiana): a novel mutualism. Journal of Experimental Biology, 303A: 704–712.
Zduniak, P., Erciyas-Yavuz, K. & Tryjanowski, P. (2017) A possible mutualistic interaction between vertebrates: frogs use water buffaloes as a foraging place. Acta Herpetologica, 12 (1): 113-11.
Royal Mail release new ‘Reintroduced Species’ stamps
Royal Mail release new ‘Reintroduced Species’ stamps
Royal Mail have just released their ‘Reintroduced Species’ stamps to celebrate some of the biggest success stories about restoring various flora and fauna to the UK. Froglife are very pleased to see the sand lizard featured on one of these stamps as it is sometimes a neglected species like most reptiles and amphibians.
Here at Froglife, we love the humble little sand lizard and aim to protect them as well as their habitats. Here are some interesting facts about them:
- One of the UK’s rarest reptiles
- Populations found in coastal areas in the South and West of the UK
- Reintroduced to sites in North Wales, Devon, Cornwall and West Sussex.
- The UK’s only native egg-laying lizard
- Males develop bright green flanks during the breeding season
- Like the common lizard, sand lizards will drop their tails if they feel threatened
- Sand lizards have full legal protection under UK law
For more facts about sand lizards, visit the advice section of our website: www.froglife.org/info-advice/amphibians-and-reptiles/sand-lizard/
To see more of the Royal Mail’s ‘Reintroduced Species’ stamps, click here.