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Climate change modelling of English amphibians and reptiles: Report to Amphibian and Reptile Conservation Trust (ARC-Trust)

Final Report: May 2012

Dunford, R.W. and Berry, P. M. Environmental Change Institute, University of Oxford Centre for the Environment, South Parks Road, Oxford, OX13QY.

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1. Introduction

Globally, amphibians, and to a lesser extent reptiles, are thought to be groups that are particularly vulnerable to climate change, especially through changes in precipitation. They are also indirectly affected through factors, such as habitat loss, increase in disease (Pounds et al. 2006; Bosch et al., 2007), pollution and predation (Cox et al., 2009; Hof et al. 2011) and it is uncertain to what extent they interact (Wake, 2012). In the UK, there are uncertainties about the proximal causes of declines, but they largely relate to anthropogenic activities (Beebee et al. 2009). Changes in amphibian and reptile populations in response to climate change have already been seen in the UK. For example, at Environmental Change Network sites, monitoring of the common frog (Rana temporaria) has shown that changes in phenological events, such as congregation, spawning and hatching, has become earlier and of extended duration (Seir and Scott, 2009). This seems to be due to increasing mean temperatures. A similar response has been observed in Brittany, with a decrease in fecundity in 2004 following the 2003 heat wave (Neveu, 2009). This illustrates the importance of not just changes in mean climatic parameters, but also of more extreme events. Recent declines in frogs and toads also are thought to be possibly attributable to climate change and the projected decreases in summer rainfall and consequential lower soil moisture especially in southern regions are thought to further impact amphibian populations (Seir and Scott, 2009). 1.1. Aims and objectives

The report’s aim is twofold, i) to improve understanding of how amphibian and reptile populations may be affected by climate change and ii) to suggest possible conservation management and policy responses to help guide future thinking and application. This equates to five key objectives:

1. Use climate-envelope modelling to identify potential changes in herpetofauna distribution; 2. For the six priority species (listed in section below), assess likely changes in habitats and their

impacts on species distributions; 3. For priority species, identify key issues that will need to be addressed in practice and via

policy; 4. Determine how the approach can be used for modelling for all herpetofauna species; 5. Identify future research needs.

1.2. Importance/Policy Context

The thirteen herpetofauna species native to the UK were included in this study. Of these, six priority species were identified for detailed study of ecology and threats; these were the common toad (Bufo bufo), smooth snake (Coronella austriaca), natterjack toad (Epidalea calamita, previously Bufo calamita), sand lizard (Lacerta agilis), great crested newt (Triturus cristatus) and the adder (Vipera berus).

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1.3. Species Selection

Table 1.1 The selected species. The six priority species are in bold. ID

Com

mon N

ame

Type

AR

C-Trust

Contract Priority

European Protection

UK

B

AP

Protection

Protection

1 Anguis fragilis Slow-worm reptile B 0 1 No Killing/Sale 2 Bufo bufo Common toad amphibian A 1 1 No Sale 3 Coronella austriaca Smooth snake reptile A 1 1 Full 4 Epidalea calamita (Bufo calamita) Natterjack toad amphibian A 1 1 Full 5 Lacerta agilis Sand lizard reptile A 1 1 Full 6 Lissotriton helveticus Palmate newt amphibian C 0 0 No Sale 7 Lissotriton vulgaris Smooth newt amphibian C 0 0 No Sale 8 Natrix natrix Grass snake reptile B 0 1 No Killing/Sale 9 Pelophylax lessonae Pool frog amphibian C 1 1 Full 10 Rana temporaria Common frog amphibian C 0 0 No Sale 11 Triturus cristatus Great crested newt amphibian A 1 1 Full 12 Vipera berus Adder reptile A 0 1 No Killing/Sale 13 Zootoca vivipara Common lizard reptile B 0 1 No Killing/Sale

2. Methodology

2.1. Climate-envelope modelling

Environmental conditions are recognised to be the primary drivers of natural distributions of most forms of life (Woodward, 1987; Huntley, 1999). Herpetofauna are no different and numerous studies have demonstrated that distributions of amphibian and reptiles can be estimated by drawing on bio-climatic data (Soares and Brito, 2007; Sillero et al., 2009; Carvalho et al., 2010; Qian et al., 2007). This project uses the SPECIES model (Pearson et al., 2002; O’Hanley, 2008), which has been used to map a variety of species in a number of UK and European contexts (Berry et al., 2002, 2003, 2007a, 2007b; Harrison et al., 2006; Holman et al. 2007). This model uses bio-climatic input variables and species distribution maps to create neural network models that link the two. Neural network approaches offer a number of advantages over traditional statistical modelling techniques in that i) they are not dependant on normally distributed input variables; ii) they are resistant to the impacts of noise in their input data and iii) they have few restrictions in the type of data that the can take (continuous / categorical / Boolean). Instead, inspired by the human nervous system, a neural network is a non-linear statistical model that ‘learns’ the relationships between input and output variables. To do this SPECIES is calibrated using a subset of the available species:climate data; the remaining proportion of the data is then used to validate the model’s predictive capacity. As each neural network is unique, precision is improved by using an ensembles approach: 20 submodels are created and each one used to estimate potential future species distributions. The final output is the sum of these models weighted by that model’s statistical performance (O’Hanley, 2008). In this project, neural networks were trained at a European scale. This was to ensure that the networks were created using a climatic range capable of representing warmer future climate scenarios. Five bio-climatic input variables are used within the SPECIES model: i) Growing degree days > 5oC; ii) the theoretical absolute minimum temperature expected over a 20-year period; iii) annual maximum

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temperature of the warmest month; iv) annual soil moisture surplus and v) annual soil moisture deficit. These variables are calculated from monthly average European baseline climate data (following Pearson et al., 2002) and mapped on a 0.5 degree grid. Input European species distributions for each of the 13 species were acquired from http://www.seh-herpetology.org/atlas/atlas.htm (Gasc et al., 1997); both “before 1970” and “after 1970” symbols were treated as presences, locations marked as “extinct” or “introduced” were excluded. These maps were converted to a digital format, digitised in ArcGIS and also mapped to the same 0.5 degree grid as the climate data. NeuralEnsembles v1.03 software (http://purl.oclc.org/NeuralEnsembles; O’Hanley, 2008) was used to create the neural network ensembles for each of the 13 species using an ensemble of 20 neural networks each created with a single hidden layer and 11 hidden units by using the RPROP training algorithm. The full customised settings are shown in Table 2.1.

Table 2.1 Neural Ensembles customised input settings.

VARIABLE SETTING Submodels 20 Ensemble Construction SECA Ensemble Averaging Weighted Network Topology Fixed Hidden Layer Architecture User-specified (1/11) Test Interval 50 Max number of training epochs 2500 Stopping Tolerance 0.001 Stagnation Limit 3 Training Algorithm RPROP Learning Rate 0.5 No training runs 3 Random shuffle Off Initial random weights (-0.1/0.1) RCmnd.exe path {located by user} Mapped presence/absence threshold Sensitivity/Specificity crossover Plotting (Observed Overlay/Headers)

2.1.1. Validation

Table 2.2 shows validation statistics for the European species distributions using Kappa and ROC statistics. Qualitative classifications of the reliability of these statistics have been suggested by Monserud and Leemans (1992) and Swets (1988) respectively and are also displayed in Table 2.2. Monserud and Leemans (1992) suggest the following ranges of agreement for Kappa: excellent K>0.85; very good 0.7<K<0.85; good 0.55<K<0.7; fair 0.4<K<0.55; and poor K<0.4. Similarly, Swets’ (1988) ranges for AUC are: excellent AUC>0.90; good 0.80<AUC<0.90; fair 0.70<AUC<0.80; poor 0.60<AUC<0.70; fail AUC<0.60. Table 2.2: Validation of the species distributions at the European scale (EU Only)

Species (Latin name) Species (Common Name)

kN

est

AU

CN

est

kN

est

AU

CN

est

Type

AR

C-Trust

Contract

European Protection

UK

B

AP

Protection

Anguis fragilis Slow-worm 0.639 0.891 Good Good reptile B 0 1 Bufo bufo Common toad 0.529 0.842 Fair Good amphibian A 1 1 Coronella austriaca Smooth snake 0.594 0.890 Good Good reptile A 1 1 Epidalea calamita (Bufo calamita)

Natterjack toad 0.717 0.942 VGood Excellent amphibian A 1 1

http://www.seh-herpetology.org/atlas/atlas.htm

http://www.seh-herpetology.org/atlas/atlas.htm

http://purl.oclc.org/NeuralEnsembles

http://jncc.defra.gov.uk/_speciespages/2039.pdf





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Lacerta agilis Sand lizard 0.658 0.917 Good Excellent reptile A 1 1 Lissotriton helveticus Palmate newt 0.784 0.970 VGood Excellent amphibian C 0 0 Lissotriton vulgaris Smooth newt 0.609 0.890 Good Good amphibian C 0 0 Natrix natrix Grass snake 0.672 0.889 Good Good reptile B 0 1 Pelophylax lessonae

Pool frog 0.572 0.891 Good Good amphibian C 1 1

Rana temporaria Common frog 0.588 0.871 Good Good amphibian C 0 0 Triturus cristatus Great-crested

newt 0.601 0.882 Good Good amphibian A 1 1

Vipera berus Adder 0.603 0.864 Good Good reptile A 0 1 Zootoca vivipara

Common lizard 0.586 0.861 Good Good reptile B 0 1

2.2. Future GB suitable climate space

To estimate future suitable climate space seven UKCIP021 scenarios were used as input data to the neural networks (http://www.ukcip.org.uk/ukcp09/ukcip02/). These provided high and low-emissions scenarios for the 2020s, 2050s and 2080s at a 5km resolution. These scenarios are the equivalents of SRES scenarios B1 (low) and A1F1 (high) (IPCC SRES, 2000); they correspond to increases in global temperature of 2.0 oC (low) and 3.9oC (high) by 2080. By feeding these networks with climatic data from modelled future scenarios, maps of climate space similar to that species’ observed extent can be estimated. The gain and loss of this space can then be used as an indicator of potential impacts of climate on the species of interest. Species vulnerability is expected to be lower for species where large amounts of appropriate future climate space are expected, particularly space that overlaps current species distributions. For those species where appropriate future climate space diminishes, and the overlap with current climate space lessens, the species vulnerability is expected to be greater. 2.3. UK Species Distributions

Species distribution data for the UK were downloaded from the UK’s National Biodiversity Network’s website at http://data.nbn.org.uk/. These were automatically converted to presence/absence images, geocorrected to the other UK datasets and then automatically digitised using ArcGIS’ raster to vector functionality. The resulting files were used to produce a shapefile at the same 5km grid as the climate data storing presence/absence data for each of the thirteen species. 2.4. Note on use of the GB scale

Although the focus of this project is on England, the data presented here are at the GB scale to provide information on the full context in terms of the estimated potential climate space for current English herpetofauna species. It is clear from many of the distributions that joined-up approaches with the devolved administrations will most likely be necessary to conserve many of England’s reptile and amphibian species.

1 It should be noted that the updated UKCIP09 data were not used for this project. This data source is far more detailed and provides full probability distribution data across a number of models and emissions scenarios. This data is ideal for exploring the full spectrum of possibilities but intentionally dissuades the user from focusing on a limited subset of the data. Processing the data down to a manageable number of scenarios would have been unnecessarily time consuming and outside of the scope of this project. For more information see http://ukclimateprojections.defra.gov.uk/22537









http://www.ukcip.org.uk/ukcp09/ukcip02/

http://data.nbn.org.uk/

http://ukclimateprojections.defra.gov.uk/22537

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3. Climate-envelope modelling of English herpetofauna

The following section addresses objectives 1-3 of this report. Section 3.1 focuses on the six priority species. It presents the results of the climate-envelope modelling (Objective 1) and also includes an analysis of likely changes in habitat and their impacts on species distributions (Objective 2). Furthermore potential adaptation response options are highlighted and policy implications are discussed so as to identify key issues that will need to be addressed in practice and via policy (Objective 3). Section 3.2 addresses the remaining species and focuses on the climate modelling alone. The results of the climate-envelope modelling are displayed in Figures 3.1-3.11; each figure is divided into three maps discussed, by species, in detail below. The first map compares modelled estimations of current appropriate climate for a particular species (in green) with the NBN distribution of species presence (black dots). It should be remembered that these distributions are trained on these species’ European distribution to ensure representation of a sufficient climatic range for warmer future scenarios. As such, the NBN data play no role in model calibration. The second and third maps show the distributions of modelled appropriate climate space in terms of change from baseline for two climate change scenarios: low-emissions, using baseline and UKCIP time slices for 2020, 2050 and 2080 low-emissions scenarios and high-emissions, which uses baseline, 2020, 2050 and 2080 high-emissions scenarios. Each graph combines these four layers in a way that highlights areas of i) stability: where the area remains appropriate for the species in question across all four time period ii) gain: where the area becomes appropriate for the species at a period of time, and remains so in the 2080s iii) loss: where an area that was appropriate for the species becomes inappropriate and remains lost to the species in the 2080s and, rarely, iv) transience: where between since baseline the area has become appropriate (i.e. been “gained”), in either the 2020s, 2050s or both, but has become inappropriate (“lost”) again by the 2080s. Gain is mapped in blue, loss mapped in red and transient sites are mapped in yellow. For sites of gain and loss the year of gain/loss is identified and mapped with darker colours representing a more recent time slice. Sections 3.1-3.13 detail the potential changes for each species, as identified using climate envelope modelling. The key areas of stability, growth and loss are highlighted in bold and coloured black, blue and red respectively to allow quick summary of the key messages. Where referenced, areas of Scotland and Wales are in italics to show that they are outside of the remit of Natural England.

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3.1. Priority Species

3.1.1. Bufo bufo (Common toad)

Climate-envelope modelling

Appropriate climate space is relatively well mapped for England, although there is an underestimation of the available appropriate climate space in the NW and SW. Underestimation is widespread in Scotland. Distributions of climate space appropriate for B. bufo in the low-emissions scenario are almost uniformly stable across England, with, from the 2020s onward, potential for gained space in the North-west and South-west of England, Scotland and Wales. It should be noted, however, that much of the space ‘gained’ in England in both scenarios includes areas where the NBN data already show B. bufo to be present at baseline. As such, the most significant positive contribution of climate change to B. bufo in England is likely to be the potential for joining up the gaps in the current species distribution, particularly in NW England, in locations where the gaps are a result of climate rather than wider habitat factors. The high-emissions scenario shows similar patterns of gain, which are more extensive in the NW and Scotland; however, areas of the south and the south coast in particular become inappropriate climate space for B. bufo by the 2080s.

Figure 3.1 Bufo bufo

a) Projected vs observed species

distributions. b) Distribution Change: Low-

emissions Scenarios c) Distribution Change: High-

emissions Scenarios Current habitat

The common toad is found primarily in water bodies and wetlands, but also in garden ponds and, less frequently in other habitats such as woodlands, marshes and roads (Arnold, 1995). Populations across large areas of south, east and central England are undergoing serious declines, and have experienced toad-population declines of 50% or more in rural areas between 1985-2000 (Carrier and Beebee,

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2003). In some locations these declines have lead to extinction or near-extinction of populations (UKBAP; JNCC, 2010a). A number of possible causes have been suggested, including loss of habitat (Cooke and Ferguson, 1976), changes in habitat management, mortalities on roads (Cooke and Sparks, 2004; Cooke, 2011) and climate change (JNCC, 2010a). It has been observed that the geographical pattern of decline in lowland England broadly corresponds to patterns of intensive farming. However, there are exceptions, such as a site in Lewes, East Sussex, where there has been no significant change in land use, but observed declines in toad populations (Carrier and Beebee, 2003). Also, breeding pairs of toads at sites where frogs are also present have a lower relative frequency of decline than where toads breed alone, but more research is needed to identify and understand the causes of these declines (Carrier and Beebee, 2003). Changes in habitats and their impacts on species distribution

The modelling has shown that while many areas of suitable climate space remain stable in England, with areas of new potential climate space in the north-west and south-west, by the 2080s areas in the south have the potential to become unsuitable under a high-emissions scenario. This suggests that, given the observed declines in this region, understanding the proximal cause(s) is very important. Water levels in ponds in southern England are likely to decrease due to lower rainfall, especially in summer and thus water management is likely to be necessary in order to maintain them. The increased interest in on-farm reservoirs, however, could offer potential new habitats. Adaptation response options:

• Prevention of further loss of ponds is particularly important, as adults have high site fidelity. Reading et al. (2001) showed that 93% of females and 96% of males that survived between years, returned to the same breeding ponds, thus continuity of sites and their quality is important;

• Increasing populations through habitat (re)creation. An active dewpond restoration and creation programme on chalk downlands in Sussex, led to an increase in common toads between 1977 and 1996, especially in higher quality ponds (Beebee, 1997). They were, however, relatively uncommon in older ponds, this was possibly due to successional processes, with colonisation by newts leading to predation of toad larvae. Garden ponds also may be decreasing in number due to concerns about safety and may become unsuitable if stocked with exotic, predatory fish. On average, there are thought to be a greater density of ponds in southern and eastern England, but there have been high losses here as well (Wood et al., 2003). For example, between 1870 and 1984 parts of London have lost 90% of their urban ponds (Langton, 1985) and the Lowland Pond Survey 1996 (Williams et al. 1998) indicated that most of the ponds lost between 1990 and 1996 were from arable land, while there was a net increase on pastoral land;

• Improving water quality, as greater colonisation and breeding success is likely (Beebee, 1997);

• Decreasing habitat fragmentation could all contribute to improving their status. Various studies have shown that common toads can migrate at least 2km (Scribner et al., 2001) and sometimes over 3km between ponds (Smith and Green, 2005), thus giving an indication of the level of connectivity required. In small, urban populations, Hitchins and Beebee (1997) found that genetic diversity, survival and development were significantly lower, due to genetic drift caused by barriers to migration.

Policy Implications

The prevention of loss of habitat (which can decrease connectivity) and better management could be achieved through agri-environment schemes and development plans, while the improved habitat quality could be assisted by the Water Frameworks Directive requiring waters to be in good ecological status. On-farm reservoirs could be supported by the Rural Development Programme for England and DEFRA’s new Farming and Forestry Improvement Scheme may be able to assist with funding.

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3.1.2. Coronella austriaca (Smooth snake)


Considering its small and patchy distribution, the map of appropriate climate space for Coronella austriaca is reasonable. A proportion of the two main patches is projected to be suitable at baseline and cells close to the more minor patches are also identified. There is, however, significant overestimation, particularly in eastern England and southern Wales which should be borne in mind when interpreting the future scenario maps. The UKCIP low-emissions scenario shows the potential for significant gains in climate space appropriate for C. austriaca whilst maintaining the stable distributions in the south of England. In the 2020s it is estimated that the appropriate space would increase to include the majority of southern and north-west England, the Midlands and Wales reaching further north in the 2050s and 2080s. However, in the low-emissions scenario the distribution is not be expected to reach as far north as the north east or Scotland by the 2080s. In the high-emissions scenario however, the majority of northern England is projected as suitable by 2080s, in addition to the south-west of England, Wales and southern and mid-Scotland. However the original, southern England home of the species could be lost in the 2080s, both in terms of the area represented by the NBN data, and the areas of appropriate climate space projected for baseline. Furthermore, large areas of southern and south-eastern England, although appropriate climate space for some years between baseline and 2080, are also modelled to be unsuitable by the 2080s. If appropriate climate space changes as modelled, C. austriaca will have to be able to make use of the period between baseline and 2080s to move north or south-west to avoid being at serious risk of losing access to appropriate climate space.

Figure 3.2 Coronella austiaca




emissions Scenarios

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Current habitat

The smooth snake is widespread in Europe, but only occurs in England on lowland heathland in Surrey, Hampshire and Dorset. It used to be also found in Devon, Berkshire, Wiltshire and Sussex (Smith, 1964). Its decline before the 1980s mirrors the loss in heathland, but its numbers now are presumed stable (UK BAP). The loss of habitat has also resulted in increasing fragmentation, as has been well-documented for Dorset (Moore, 1962; Webb & Haskins, 1980; Chapman et al., 1989; Webb, 1990; Rose et al., 2000), where it has been associated with increased urbanisation and fires. Agricultural intensification can also contribute to this habitat loss (Natural England, 2011). An information-theoretic model developed to investigate the impacts of fragment parameters on smooth snake occupancy showed that while the area of remnant heathland patches was of primary importance, the composition of surrounding matrix habitats was also important (Pernetta, 2009). The conservation of smooth snake is dependent on heath management, including the controlling of burning and over-grazing, scrub removal and the provision of a range of heather ages.

Changes in habitats and their impacts on species distribution

Based on SPECIES bio-climate enveloping modelling of a number of dominant, sensitive and species of conservation concern, lowland heathland in southern England is projected to be adversely affected by climate change: many of the dominant ericaceous species could lose suitable climate space by the 2050s. This would lead to important changes in species composition and possibly ecosystem structure (Berry et al., 2005; Berry and O’Hanley, 2007; Berry and Paterson, 2009). This could mean that there is a need to explore the possibility of encouraging the use of other habitats by smooth snakes. Also, consideration could be given to alternative ericaceous species, such as Dorset heath (Erica ciliaris) which is a minor component of the Dorset heaths, but has shown a recent increase (Preston et al., 2002) and the translocation of Cornish heath (Erica vagans) from Cornwall. Little is known about their response to climate change. Modeling by Huntley et al. (1995) suggests that the response of Dorset heath is dependent on the climate scenario selected. Cornish heath, however is thought to be resilient to climate change (Joint Nature Conservation Committee, 2007), but it is not known whether the rest of southern England represents suitable climate space, such that it might be a suitable candidate for habitat re-creation should the other heathers be lost. Adaptation response options:

Given that the smooth snakes are projected to be adversely affected in southern and south eastern England by the 2080s and its main habitat is projected to lose climate space by the 2050s, adaptation will become increasingly important. For southern and south eastern England:

• Maintain habitat heterogeneity on reserves, including different ages of heather to meet the requirements of the snakes at various times of the year and south-facing heath banks and slopes for basking (Natural England , 2011);

• Decrease tree cover, but increase gorse (Ulex spp.) cover (Pernetta, 2009). It is thought that gorse increases the frequency of ants’ nests, which are used as refuges by smooth snakes (Bliss, 2000). This would, however, conflict with habitat management for sand lizard, as they require more open conditions and some trees to provide shade in summer (Pernetta, 2009);

• Decrease area of bare ground (Pernetta, 2009; Natural England, 2011). NB This is likely to be a consequence of the above action and is also in opposition to management for sand lizards;

• Avoid disturbing the soil, especially between October and February, when smooth snakes are hibernating underground (Natural England, 2011);

• Increase populations of slow worms (Anguis fragilis) (Pernetta, 2009), as they are a known prey source (Reading, 2004);

• Relocate populations where sites are threatened by development (Spellerberg and Phelps, 1977). Pernetta (2009) suggests that, in Dorset, snakes should only be moved between sites

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that would have been part of the same heathland in the past, in order to maximise genetic diversity retention. Edgar et al., (2005) argue that when pre-development translocation is to take place care needs to be taken to ensure that the new habitat is equivalent to the old, to minimise overall habitat loss. Furthermore, they stress the importance of post-translocation monitoring and better record keeping to ensure that post-development translocation meets its conservation aims (see also section 3.1.5);

• Fire management to prevent loss of habitat; • Increase size of heathland fragments (Pernetta, 2009); • Increase site connectivity, this could include ensuring that suitable non-reserve sites are

managed appropriately. For areas which are gaining suitable climate space:

Ensure that potential heathland sites have appropriate site conditions, such as a range of heather ages, a small-scale mosaic of low-level vegetation, bare ground and limited scrub (Natural England, 2011). Translocation into new potential areas close to existing sites, especially where connections to them are poor, as smooth snakes have poor dispersal ability. The adaptation options for southern and south eastern England include many important management actions which would help to enhance or maintain potential future sites. Policy Implications

Given the importance of lowland heathland for this species, it has been suggested that it should be linked to the Lowland Heathland Action Plan to ensure favourable management (UKBAP). Ensuring that non-reserve areas are managed favourably could be achieved through agri-environment schemes, such as Environmental Stewardship (UKBAP, Natural England, 2011), although the future of these under CAP reform remains to be seen.

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3.1.3. Epidalea calamita (natterjack toad; also Bufo calamita)

Epidalea calamita has a small and patchy distribution; the modelled appropriate climate space captures the large proportion of the south and south-eastern and distributions. However, NBN-recorded species presences in the Midlands and northern England are not identified. Furthermore, available climate space is identified in the south-west of England and southern Wales where no species occurrences are recorded in the NBN, and considerably more area in the South-east is identified as appropriate than has been identified by the NBN as supporting E. calamita. Whilst factors other than climate (e.g. habitat availability, human impacts) may contribute to the explanation of the overestimations, the under estimations in the north must be borne in mind when interpreting the future distributions of appropriate climate space. Appropriate climate space for E. calamita under the low-emissions scenario shows signs of increasing northward from baseline to the 2080s. The locations of the existing southern and south-eastern E. calamita populations remain stable within appropriate climate space through to the 2080s. In addition, as early as the 2020s, most of south, south-west, south-east England and the Midlands is considered appropriate; in the 2050s and 2080s this stretches into coastal northern England and Wales covering all the NBN-identified E. Calamita sites in Britain. In the 2080s, only inland-northern England, central and eastern Scotland are modelled to remain unsuitable for the species.

Figure 3.3 Epidalea calamita




emissions Scenarios

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However, under the high-emissions scenario, projected gains in terms of the entirety of south-western and northern England, the midlands, Wales and a large proportion of Scotland, are counterbalanced by projected losses of appropriate climate space in the south and south east of England and southern Wales in the 2080s. These losses are particularly significant as they include one of the primary southern NBN E. calamita sites. The Merseyside and East Anglian E. calamita sites remain in stable climate space in both scenarios, suggesting that the entire English distribution of the species may not be at risk by the 2080s. However, the loss of the southern sites, and the potential expansion of the small area of loss in the north-west high-emissions scenario clearly suggests that, without movement to compensate for climate change, a significant proportion of the English E. calamita population could be at risk of losing its appropriate climate space. Current habitat

Natterjack toads are found on coastal sand dunes, saltmarsh, grazing marsh and lowland heaths. There was a large population decline in the early part of the 20th century and by the 1970s there were only about 40 known populations (Denton et al., 1997). In Britain, they occur in three regions (north-west England, south-west Scotland and eastern and southern England) in highly fragmented populations (Beebee, 1997). The largest populations with the highest densities are located on the Irish Sea coast (Beebee, 1985). Changes in habitats and their impacts on species distribution

The natterjack toad has undergone large declines in the past, due to seral succession, as well as habitat loss and fragmentation resulting from urbanisation and afforestation. The changes in habitat structure resulting from succession, however, resulted in suitable conditions for the common toad (Denton et al., 1997) and the earlier breeding of this toad has led to its tadpoles outcompeting those of the natterjack toad (Banks and Beebee, 1987a; Griffiths, 1991). There has been an extensive conservation effort since the 1970s, including a Species Recovery programme. This work included the restoration and maintenance of early successional habitats on dunes and heaths, enhancing populations, pond creation, countering pond acidification and translocations, ideally to sites within its historical range (Denton et al., 1997). These have met with varying degrees of success depending on site conditions. For example, between 1970 and 1999 there has been a slight increase in the number of populations due to successful translocations outweighing extinctions (Buckley and Beebee, 2004). It has become clear that a holistic approach to management is required at the habitat to landscape scale (Denton et al., 1997). Efforts to understand population dynamics and the role of environmental factors have helped to increase understanding of the ecology of the species. An investigation in Switzerland into whether habitat factors, local population size or metapopulation characteristics best explained the (local) distribution of natterjack toads, found that the number of calling males (local population size) in the previous years was the best predictor. Conversely, site occupancy was inversely related to connectivity (Schmidt and Pellet, 2005). It was suggested that the latter could be related to conspecific attraction, with females preferring ponds where there were more calling males, which could lead to populations in nearby ponds going extinct. There was, however, some evidence that ponds that were empty one year had a more than 20% chance of being occupied the following year. Habitat variables did not seem to be important and research is needed to determine the temporal and spatial scale(s) at which they are important for predicting site occupancy. This is important for guiding site management. There appears to be a certain geographic synchronicity in (some) stages of the breeding cycle. Data on British populations has shown that, in thriving populations, the reproductive season in the west tends to start and finish earlier than those in eastern England, but that first records of metamorphosis occur at similar times throughout the country (Beebee, 1985). A study of 36 populations in three regions in Ireland showed a regional synchrony in the start date and duration of the breeding season in any given year (Aubry et al., 2012). This was thought to be explained by temperature and precipitation

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parameters, with minimum air temperatures and cumulative degree days in early spring (15 March–15 April) possibly explaining the start of breeding time. However, earlier breeding has also been associated with air temperatures in the previous month (Beebee 1995, Reading 2003); periods of heavy rain (Sinsch, 1992); and higher levels of rainfall (Diazpaniagua, 1992). Spawning appears to be adversely affected by low water tables in spring, or low spring rainfall and generally more females choose to spawn in wetter springs (Buckley and Beebee, 2001). A study in the Rhineland, Germany, found that under favourable weather conditions during most of the reproductive period, the temperature and surface area of pond only partially explained the temporal variation in breeding statistics (23.4%-41.0%; Sinsch, 1988). Desiccation of shallow, natural dune slacks and saltmarsh pools has been shown to lead to mortality during the developmental phase, while high water temperatures can lead to metamorphic success (Banks and Beebee, 1988). Under climate change, increased winter and spring temperatures could favour earlier spawning, as could higher winter precipitation, but given the regional variation in projections of future rainfall not all areas of Britain will necessarily experience wetter springs and higher water tables. These conditions are most likely to not occur in southern England, thus reinforcing the projections of future suitable climate space for natterjack toads. Habitat also has a role to play in breeding success, as females usually deposit their spawn string in shallow water, away from other spawn and often in bare areas (Buckley and Beebee, 2001). On heathland is has been shown that pond chemistry, especially pH, and Na and SO4 levels are major factors affecting site choice, while on coastal dunes the maximum water temperature on the day prior to spawning was important (Banks and Beebee, 1987b). Also it has been shown that adult population density and toadlet production was five and 2.9 times higher respectively on a nutrient rich dune than on a nutrient poor heathland (Banks and Beebee, 1988). Low pH (<6) can also lead to developmental failure of spawn and reduced growth rates, whilst abundant food supply can lead to metamorphic success (Banks and Beebee, 1988). Coastal sand dunes and marshes will be particularly affected under climate change by sea level rise. If they are able to migrate inland, then there should still be appropriate habitat for natterjack toads, although the exact extent may vary according the topography inland. Where artificial sea defences or developments prevent their movement inland, then habitat loss would put additional pressure on the toads. As has been seen for smooth snakes (Section 3.3), lowland heaths, particularly in southern England, could be adversely affected by climate change. The reproductive success of natterjack toads can also be affected by the presence of predators or infections and it has between shown that the toads are able to discriminate against ponds with a high number of competing species, such as common toad and common frog larvae (Banks and Beebee, 1987b). The predation of tadpoles by invertebrates, including dytiscid water beetles, Notonecta species, Odonata larvae and the great crested newt, can lead to mortality during the developmental phase. There is also an inverse relationship between toadlet production and number of invertebrate predators in breeding pools, which is related to pond permanence (Banks and Beebee, 1988). Thus, there is an apparent trade-off between greater water depth which decreases desiccation, but also increased mortality from invertebrate predation. Low temperature can lead to infestation with Saprolegnia and developmental failure (Banks and Beebee, 1988). In order to realise new suitable climate space or colonise new ponds, natterjack toads will need to migrate. Adults appear to have high breeding area fidelity, although they move substantially between seasonal habitats, but most dispersal events seem to be undertaken by juveniles (Denton and Beebee 1993; Sinsch 1997). A cost-distance model, based on experiments on natterjack movement through real landscapes, showed that in southern Belgium dispersal rates may be explained by the landscape structure, and also that the toads showed a preference for forest elements and tended to avoid agricultural land (Steven et al., 2006).

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Adaptation response options:

• Increase in ponds and slacks of appropriate water depth and quality for breeding. Factors affecting pond choice are thought also to be related to the shape and size of the pond (Banks and Beebee, 1987b);

• Habitat restoration and maintenance, particularly through the ongoing management of succession;

• Translocation of populations threatened with extirpation; • Removal of predators, although there would be conflicts of conservation interests in the case

of great crested newt (Banks and Beebee, 1988); • Increasing connectivity could also help in migration, but more research is needed on potential

routes across the landscape, given the slightly surprising findings of Steven et al. (2006) that forest was preferred for movement;

• Maintain/create habitat heterogeneity to meet the asynchrony in population dynamics at the local level (Semlitsch, 2002, Werner et al., 2009). This is also likely to benefit other amphibian and invertebrate species associated with these habitats (Aubry et al., 2012).

Policy implications

Given that natterjack toad habitats are all UK priority habitats and that the majority of the adaptation actions relate to habitat management, some of the actions are already consistent with the Habitat Action Plans or could be built into them. However, as has been identified above, there are conflicting requirements for several of the amphibian and reptiles species. Management of ponds and water quality could benefit from the Water Framework Directive.

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3.1.4. Lacerta agilis (Sand lizard)


The very patchy distribution of Lacerta agilis represented by the NBN data proved to be very difficult to model. Either there are a number of factors beyond climate that drive the distribution as it is found in the UK, or the factors within the European training data do not reflect the drivers at the UK scale. The projection fails to identify appropriate climate space for the major L. agilis hotspots from the NBN data, especially in S and SW England. Instead, appropriate climate space is identified across the Midlands and the south east; whilst there are L. agilis sites within these areas, it is strongly recommended these mismatches are seriously considered when interpreting the future appropriate climate distributions. With this reflection in mind, both low and high-emissions scenarios show a pretty bleak picture for species with this initial distribution of appropriate climate space. Under the low-emission scenario, climate space loss begins to spread outwards from the East Midlands in the 2020s, the majority of the southern and midland distribution of available climate space is totally lost by the 2080s replaced by very small gains of climate space in the North East and small areas of the West Midlands. In the high-emissions scenario the vast majority of the English distribution of climate space is lost by the 2050s with only a few transitional areas providing potential climatic stepping stones to tiny areas in northern England and Scotland. If the appropriate climate distribution mapped here is at all relevant to L. agilis, and the relatively solid European validation statistics (kappa = 0.65, AUC=0.92) allow us to at least consider this possibility, there may well be some warnings to be taken in terms of potential for rapid decline. However, the existence of UK specimens outside of the estimated appropriate distribution, suggests that further work is needed to identify the reasons for the significant differences between modelled appropriate climate and the NBN data before drawing conclusions.

Figure 3.4 Lacerta agilis




emissions Scenarios

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Current habitat

The sand lizard is habitat restricted to lowland heaths and sand dunes particularly in the south of England. Sand lizard populations had retracted so that they could only be found in small parts of southern England: Dorset, Sussex, Hampshire, Surrey and the Sefton Coast in North-west England. This loss has mainly been attributed to habitat destruction and fragmentation due to development as well as less appropriate climate (Jackson et al., 1979). More recently, sand lizard populations have been re-introduced to areas such as Devon, the New Forest, the Weald and Wales where they had previously died out (Natural England, 2011). Changes in habitats and their impacts on species distribution L. agilis is reliant on i) isolated and predominantly south-facing mature heath or dune habitat with a varied vegetation structure, used for body temperature regulation, cover and hunting and ii) unshaded, bare sand, essential for egg incubation. Much of its former bare sand habitat has been lost to development or made unsuitable as a result of shading. (Moulton and Corbett, 1999). Furthermore, significant amounts of the heathland and dune habitat have also been lost, deteriorated or fragmented as a result of pressures from development, forestry, mineral extraction and natural encroachment by birch, pine, bracken and other scrub. Uncontrolled fires also have a detrimental impact (UKBAP, 1995b; Arc Trust, 2009). The projected increase in future temperatures may mean that, in the short term, more available habitat could develop as a result of improved egg incubation conditions (Thomas et al., 1999). However, as noted for the natterjack toad (E. calamita), coastal sand dunes and marshes will be particularly affected under climate change by sea level rise (section 3.1.3). If they are able to migrate inland, then there should still be appropriate habitat for sand lizards, although the exact extent may vary according the topography inland. Furthermore, future climate modelling of heathland species, suggests that suitable climate space for many of the dominant ericaceous species have the potential to reduce significantly by the 2050s (Berry et al., 2005; Berry and O’Hanley, 2007; Berry and Patterson, 2009). This is particularly significant for the lowland heathlands of southern England where sand lizard populations exist and have been reintroduced. As discussed with smooth snake (section 3.1.2), it may be possible to encourage the species to use alternative, more climate resilient heathland species (e.g. Preston et al. 2002) or translocate the species to more northern areas. It is the structural complexity of the heathland that L. agilis prefers rather than the specific heathland species (House and Spellerberg, 1983). Despite having relatively specific habitat needs, sand lizards have demonstrated the ability to survive in both chalk and clay heaths, as well as in some secondary habitats derived from a combination of lowland dry heath and dune, such as private gardens rubble piles and rough grassland, providing that there is adequate cover and foraging space, and areas of exposed sand for incubation (Moulton and Corbett, 1999). Adaptation response options:

• Sympathetic local management: L. agilis habitats, both heathland and sand dune need to be well and carefully managed. Activities such as tree/scrub management, sand maintenance and fire wardening can all have a significant impact and need to be well planned. Sand dunes particularly must be considered as a whole system rather than as individual sites and heathlands should be managed to specifically maintain their heterogeneity (ARC Trust, 2009).

• Controlling dune encroachment by grasses: Wouters et al. (2012) use a remote-sensing based methodology to determine the impacts of encroachment of tall grasses and shrubs on L. agilis habitat in a 56.7ha study site in the Netherlands from 1987-2003. They show that the limiting factor controlling habitat suitability has changed from too limited coverage of shrub and too wide an expanse of low vegetation and sand in 1987 to a situation where too little exposed sand is available in 2003. They argue that management needs to take place at a local scale to ensure landscape heterogeneity.

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• Management strategies that look holistically at the management of both L. agilis and smooth snake (C. austriaca) will be needed to protect both (ARC Trust, 2009). Both species need well maintained heath and dunes. The two species will have different needs however, with the management for the snakes looking to decrease tree but increase gorse (Ulex spp.) cover (Pernetta, 2009). Sand lizards, however, need more open conditions and some trees to provide shade in summer. Clearly holistic management will be needed to ensure that the same habitat is managed in a way that there is sufficient micro-habitat for both species (Pernetta, 2009).

• Re-introduction: successful sand lizard reintroductions have taken place in numerous UK counties (Natural England, 2011). Future reintroductions could take into consideration future distributions of heathland species as mapped by models such as SPECIES.

• Connectivity: habitat linkages between current sites provide options for greater resilience.

Policy Implications

Due to the similarity in their habitat dependences many of the actions taken to safeguard L. agilis can be performed in conjunction with those to preserve the priority species C. austriaca, smooth snake, see section 3.3 above. Both species’ distributions are constrained by the availability of lowland heath and dunes; to encourage good management, it would make sense to link it to the Lowland Heathland Action Plan (UKBAP, 1995). Additionally, in non-reserve areas, there may be a role to be played by agri-environment schemes such as environmental stewardships (Natural England, 2011). Policies at a national, local and district authority levels also have a role to play in the management of these species, as well as a source of funding for both research and conservation work. Local Development Plans, Mineral Plans and Forestry Design Plans all play a role in ensuring the best management of key habitats (UKBAP, 2009).

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3.1.5. Triturus cristatus (Great crested newt)


The distribution of appropriate climate space matches relatively well with the NBN Triturus cristatus data. In England, the appropriate climate distribution shows an eastern bias that leads to underestimation of climate space in north-west England, but a relatively accurate match with the NBN distributions in central and south-west England, Wales and eastern Scotland. In the low-emissions scenario coastal east England and the North-East retain stable distributions of available climate space, as does the West Midlands. However losses of climate space, beginning in the 2050s and 2080s occur in relatively large areas of central and southern England. In the high-emissions scenario the area lost is considerably greater and only a tiny proportion of England, pockets in North-East England and on the Yorkshire coast, remains stable. The remainder, the vast majority of the country, becomes unsuitable with central England becoming unsuitable in the 2050s, followed by the North and West in the 2080s. In both scenarios the only gains in climate space are in small pockets of central northern England and in Scotland.

Figure 3.5 Triturus cristatus




emissions Scenarios The modelling suggests that, irrespective of emissions scenario significant proportions of the current geographical range of T. cristatus, as shown by the NBN data, are projected to be in areas that will become unsuitable in the 2050s and 2080s. The high-emissions scenario raises particular concern as it implies that a once widespread English species could be restricted to a very small proportion of northern England. It is, however, worth noting that there is a regional population of T. cristatus shown by the NBN data in the north-west of England that is never modelled to be in appropriate climate space. Further analysis, potentially using nested UK climate and species distributions in the model

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training data may offer improved information and help to explain this anomaly and better describe the national T. cristatus projections as well (see section 4.3). Current habitat England supports populations of great crested newts that are highly important at an international scale. The best guess estimates of their numbers from UKBAP (1995a) indicate that there are around 71000 in the UK of which 66000 are in England. Despite these numbers it is clear that the great crested newt population, which declined significantly before the 1980s, has continued to decline more recently. Some data sources suggest annual population losses of up to 5% in various areas of Britain (JNCC, 2010b). In terms of habitat, great crested newts need both terrestrial and aquatic habitats to enable them to breed, forage, disperse and hibernate. The newt can be found in a number of aquatic habitats, but they are most often found in medium to large sized ponds typically on farmland. Great crested newts preferring open, not overly shaded, ponds that do not support fish or ducks, but are close to other ponds and have clean water and abundant aquatic vegetation to breed. Outside of breeding season the newts need suitable terrestrial habitat to allow them ground cover for foraging, sheltering and hibernation (HCT, 2001). This can often be in the form of rough grass, scrub or woodland, particularly those with available hibernation sites such as piles of logs or stones, dry stone walls, deciduous woodland and scrub (HCT, 2007). Changes in habitats and their impacts on species distribution Losses of T. cristatus populations have been tied to changes in terms of the reduction of both terrestrial and aquatic habitats. Aquatic habitats are lost as potential great crested newt breeding sites due to pond removal, pollution, loss to succession or change in use through fish introduction (see also notes on pond loss in section 3.1.1). Terrestrial habitats are also being lost and fragmented and management plans that do not specifically consider great crested newts can often unintentionally render habitats unsuitable to them. In the context of a changing climate the potential for warmer, drier summer summers will likely have significant impacts on the number of available ponds and water levels within them, particularly in more southerly areas.

Adaptation response options

• Modify farming practices/ Recreate habitat: As many of the great crested newt losses in habitat are as a result of changing farming practices many adaptation approaches, certainly in the short-term, will need to follow current conservation recommendations. A landscape-scale approach needs to be taken that integrates long-term conservation goals (JNCC, 2010). This should focus on restoring, improving, creating and re-creating suitable aquatic habitats and improving water quality. However, as Denoël and Ficetola (2009) note, having a high number of ponds is of little use if the ponds do not contain appropriate habitat.Rannap et al. (2009) provide a case study from Estonia where the coupled restoration of existing ponds with the creation of new ponds led to a 2.3 times increase in great crested newt population. They also note that the great crested newt preferentially colonised ponds with submerged vegetation surrounded by a mosaic of forest and open habitats.

• When planning habitat restoration/improvement for the maintenance T. cristatus, studies show that newts have a preference for deep wetlands (Denoël and Ficetola, 2009) and ponds with higher temperatures, nitrate and phosphorus levels, but use sites with lower nutrient levels for breeding (Gustafson et al., 2009). In terms of terrestrial habitat, the newts prefer heterogeneous, less intensively managed areas. Additionally, Gustaffson et al. (2011) demonstrate that more T. cristatus occupied ponds found near deciduous forests, pasture and meadows in preference to coniferous forests and mire.

• Protecting and restoring breeding ponds and enhancing terrestrial habitat are key mechanisms targeting these issues (JNCC, 2010). However, as newts strongly avoid ponds where fish are present (Cooke and Frazer, 1976, Denoël and Ficetola, 2009), it will not be possible to combine great crested newt restoration with approaches aiming to improve fish stocks. Denoël and Ficetola (2009) suggest that the best approach may well be to let the ponds continue to serve their role of watering cattle and providing water reserves, with intervention

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where excess organic matter, or re-digging are needed to ensure sufficient water depth. Similarly newts are highly efficient predators of frog and toad larvae, and can out compete these species (Cooke, 1974; Beebee, 1997). Consequently, the conservation approaches for T. cristatus will need to consider the knock on impacts on B. bufo, E. calamita, R. temporaria and P. lessonae. A one-solution-fits-all approach will not work and holistic planning will be needed to safeguard all species.

• Increase habitat connectivity: Due to the widespread nature of the species, long-term issues resulting from the potential loss of climate space can be well addressed by forward planning, and will be enhanced by habitat recreation measures that ensuring connectivity between known sites.

• Translocation: Edgar et al. (2005) investigated examples of UK T. cristatus translocations following conflicts of interest between development and conservation. They indicate that reports are not filed on the translocation work for 50% of the instances, and that about 27% of the terrestrial habitat and half of the ponds were destroyed. They stress that care is needed to ensure that the translocation leaves the newts with a similar level of habitat to that they have lost, and that post-translocation monitoring takes place to ensure newt survival. These lessons learnt should be taken into consideration when considering translocation as an adaptation option.

• Monitoring: Although not an adaptation strategy, it is clear that much greater monitoring of the existing T. cristatus populations is necessary to guide conservation/adaptation efforts and to establish the success of any actions (JNCC, 2010).

Policy implications

Agri-environment schemes provide a useful mechanism for ensuring the restoration of appropriate habitats for the great crested newt. Efforts focussed on pond recreation and de-homogenisation of habitat will assist not only T. cristatus, but a number of priority species including Bufo bufo, the common toad. The EU Water Framework Directive provides a driver to encourage the necessary changes. In addition the inclusion of ponds as a priority habitat in 2007 has provided an additional delivery mechanism for improving great crested newt conservation. If identified early (see note above on monitoring) local authority development, land allocation and development-scheme plans can ensure that the species and the habitat it depends on are preserved where possible, particularly with reference to brownfield sites (JNCC, 2010). As with B. bufo, on-farm reservoir schemes may also provide additional potential habitats and DEFRA’s Farming and Forestry Improvement scheme may provide a funding mechanism to assist with their development.

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3.1.6. Vipera berus (Adder)


Viper berus distributions are widespread, but patchy; the modelled appropriate climate space for baseline clearly struggles to match it, particularly in south and south-west England, Scotland and Wales. That said, populations identified in the NBN maps for central and eastern England are fairly well represented with overestimations likely to reflect the influence of factors beyond climate that drive the V. berus distribution. Future scenarios suggest significant losses of appropriate climate space for England’s V. berus populations under both low and high-emission scenarios. Both scenarios show loss, starting in Eastern England in the 2020s and expanding to include all central and southern England in the 2050s and 2080s. The differences between the scenarios are that in the low-emissions scenario a small area of stable climate space is maintained in north-east and north-west England, on the Yorkshire coast and in south-east and north-west Scotland; whereas in the high-emissions scenario these locations are also lost with only NW Scotland maintaining stable climate space by the 2080s. The implications for the existing English distribution of V. berus are similar to those for T. cristatus – potential for significant reduction of a once-prevalent species to small areas of northern England, particularly under a scenario of high-emissions. However, the south-western V. berus population is never modelled to be under appropriate climate space; as such, V. berus too may benefit from further analysis potentially making use of UK climate and species data in model training.

Figure 3.6 Vipera berus




emissions Scenarios

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Current distribution Adder is widely distributed in England, but the populations are fragmented. It is found in a number of habitats, including grassland, heathland, fen, blanket and raised bog, maritime cliffs and sand dunes, all of which will be affected by climate change to varying degrees. There is evidence of national declines in adders, with the greatest declines being observed in the Midlands (Baker et al., 2004) and severe declines in several counties (Warwickshire, Worcestershire, Shropshire, London and Hertfordshire) have already been reported (UKBAP). The current threats are thought to be habitat fragmentation, afforestation, inbreeding effects, inappropriate habitat management, public pressure and persecution (Baker et al., 2004; Beebee et al., 2009; UKBAP). Appropriate habitat management was a positive factor at more than 40 per cent of adder sites (Baker et al., 2004). Changes in habitats and their impacts on species distribution Grassland and heathland will be affected by projected changes in temperature and precipitation; the wetland habitats are likely to be more affected by precipitation changes, while the coastal habitats are more likely to be affected by sea level rise. The precise effect of climate change on habitats is very difficult to model, but through modelling a range of dominant, climate sensitive and rare species some insights have been gained into the potential impacts on various habitats (Berry et al., 2003a, b, 2005, 2007; Berry and Harley, 2006). The potential effects on lowland heathland in southern England have been discussed in Section 3.1.2. Adaptation response options There are a number of possible adaptation options for addressing the various current threats and potential climate change impacts of the species and its habitats. These include:

• Improve habitat condition and undertake appropriate management, especially on designated sites (Baker et al., 2004; UKBAP), including ensuring suitable sites for hibernation and breeding (Spellerberg, 1975). This may enhance their resilience to climate change, especially if sites are managed for heterogeneity and potential future conditions, as well as human disturbance and persecution;

• Enlarge (protected) sites to increase population size (Baker et al., 2004). This may enhance their resilience to climate change;

• Improve site connectivity (Baker et al., 2004). This will facilitate species dispersal in response to climate change. It may also facilitate widening the breeding pool;

• Translocation to new sites. Policy The incorporation of the site requirements of the adder into the relevant BAP Habitat Management Plans would be an important way of enhancing populations. It has also been suggested that it would benefit from its needs being taken into account in development plans, agri-environment schemes and, more generally, by any involved in any land management planning (UK BAP).

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3.2. Other Species

3.2.1. Anguis fragilis (Slow worm)

The estimation of baseline appropriate climate space for Anguis fragilis matches the NBN distributions relatively well. There is some overestimation of appropriate climate space in the east of England, and an underestimation of the appropriate climate space in some parts of SW England, Scotland and Wales. Climate modelling suggests that, under a low-emissions scenario, the available climate space for A. fragilis is mostly stable and likely to increase with time; areas of Northern and SW England become appropriate for the species as early as the 2020s. However, under the high-emissions scenario this stability is less widespread. Instead, whilst Northern and SW England remain areas of potential new appropriate climate space for the species, a great proportion of southern England and the Midlands becoming climatically unsuitable in the 2080s. Scotland and Wales also both see large gains in terms of new areas of appropriate climate space. Similar to B. bufo, these ‘gains’ are mostly in areas where NBN data shows extant A. fragilis populations so the gains are most likely to be significant for joining up the gaps in the current species distribution, where gaps are driven by climate rather than wider habitat factors.

Figure 3.7 Anguis fragilis




emissions Scenarios

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3.2.2. Lissotriton helveticus (Palmate newt)

Lissotriton helveticus is widely, but patchily, distributed across Great Britain. The modelled distribution of appropriate climate space reflects this by predicting widespread appropriate climate space across the majority of the England, Wales and Scotland with only very few sites identified as climatically inappropriate in central Northern England, Central Scotland and the Scottish islands. This represents a large overestimation of the appropriateness of climate in eastern England, a factor that bears consideration within the analysis, but is reasonable for the rest of the country. NB overestimation could be as a result of strong habitat association and lack of its availability. With such a wide suitable climatic range, widespread stable climate space is identified for L. helveticus across the vast majority England through to the 2080s under the low-emissions scenario, with even the small absence areas in central Northern England becoming appropriate by the 2080s. With the high-emissions scenario, similar patterns of stability are present for the South-West, Midland and Northern England and East Anglia, however some areas of southern England and southern Wales become inappropriate in 2080. As some of these areas show L. helveticus populations in the NBN data these populations may be at risk if unable to relocate to more appropriate climate space. However, with the large amount of available appropriate climate space, and the widespread NBN distribution the modelling presented here suggests that it is unlikely that climate change to the 2080s poses a significant threat to the extinction of this species.

Figure 3.8 Lissotriton helveticus




emissions Scenarios

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3.2.3. Lissotriton vulgaris (Smooth newt)

The match between UK NBN Lissotriton vulgaris distribution and the estimated appropriate climate space for the species is very good. In England, the majority of NBN sites are well estimated. There are, however, some minor overprojections in East Anglia, the South West Peninsula and Wales. Furthermore, the general pattern for Scotland is exceedingly well matched, inspiring greater confidence in the appropriate climate space distribution. Climate modelling for the low-emissions scenario shows that, the east and south-west of England become inappropriate in the 2020s. Furthermore throughout the 2050s and 2080s, the Midlands and south-east England also lose appropriate climate space – by the 2080s a significant proportion of the southern proportion of the climate space appropriate for L. vulgaris is lost. Whilst the L.vulgaris sites in Northern England remain for the most part stable, with some areas in central north England and Scotland becoming appropriate from the 2020s, the impacts of a loss of southern climate space would be significant as there are numerous NBN observations of L. vulgaris in these areas. The high-emissions scenario presents a bleaker picture with the majority of England and Wales both losing their distributions of appropriate climate space lost by 2080s, with a large proportion of southern and midland England becoming unsuitable by the 2050s. Only a few small areas in central northern England and northern Scotland show any signs of stability or gain. These findings are particularly worrying as, if this scenario were to come to pass, there it would only be this small region of England that would hold appropriate conditions for L. vulgaris; the lack of existing population data in these areas on the NBN maps increases this concern.

Figure 3.9 Lissotriton vulgaris




emissions Scenarios

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3.2.4. Natrix natrix (Grass snake)

The NBN distribution of Natrix natrix is relatively well matched by the map of estimated appropriate climate space for the species. The southern and midland England distributions are well captured, however there is some underestimation of appropriate climate space in northern England, northern Wales and Scotland. The low-emissions map suggest that N. natrix populations in the midland and southern England will remain stable through to the 2080s. In addition, the model estimates an increase in available climate space into northern England, Wales and Scotland, to the point that by the 2080s all N. natrix sites currently identified by the NBN would be under appropriate climate space. The high-emissions scenario shows a similar pattern of stability, with gains extending further into Scotland but some areas of loss identified in central southern England by the 2080s. This loss of appropriate climate space will have significant impacts on populations identified by the NBN data at a local scale. However, as a significant amount of stable space is present even under the high-emissions scenario, there are gains of appropriate climate space in the north and the current NBN data shows the species to be widely distributed the species should be relatively robust against the negative impacts of climate change to the 2080s.

Figure 3.10 Natrix natrix




emissions Scenarios

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3.2.5. Pelophylax lessonae (Pool frog)

Pelophylax lessonae is only present in very small pockets of Great Britain where it is not native but introduced. Considering this the estimated available climate space is relatively close to one of the locations identified by the NBN as supporting a P. lessonae population. However, as the species is introduced there would be no expectation that NBN species presence should be evidence for appropriate climate space. Furthermore, the area is very small and the other locations, along the south coast, East Anglia and on the border with N Wales are not identified. As such it is with great care and no small amount of scepticism that the results of the analysis of future appropriate climate space should be interpreted.

Figure 3.11 Peleophylax lessonae




emissions Scenarios If the climate space of this location is seen to be representative of the overall species distribution, then, under a low-emissions scenario, available appropriate climate space for P. lessonae increases first to south east England and East Anglia in the 2020s and 2050s before spreading further north to areas of the Midlands and Yorkshire in the 2080s; the majority of current NBN sites are within these areas of appropriate climate space. In the high-emissions scenario, however, many of these areas of central England become transient in terms of appropriate climate space, and by the 2080s are no longer appropriate; none of the current sites for P. lessonae on the NBN maps are in areas appropriate in the 2080s. Instead, for the species to be able to naturalise in areas of appropriate climate space it would need to be able to make use of these transient areas of climate space to move to areas of gain: the South East and East Anglian coasts (from the 2020s), further north in areas of the West Midlands or Yorkshire (available in the 2050s), the North East and Scotland (from the 2080s). The necessity of species movement to find appropriate climate space under this scenario would raise significant concerns for the ability of the current English P. lessonae distribution to autonomously adapt to the impacts of climate change by the 2080s. However, the previously mentioned issues with

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the data suggest that these concerns must be weighed against questions of the reliability of the data and the appropriateness of the future available climate maps.

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3.2.6. Rana temporaria (Common frog)

The common frog (Rana temporaria) is distributed across the majority of the United Kingdom. At the England scale, the estimated appropriate climate space for baseline shows a very good match, in that it projects species presence across the entire country bar small patches in north-west England. However, there is more significant underestimation of the distribution in Scotland, which may suggest that the distribution is not as robust for the UK as it appears for England. Although this should be borne in mind in the interpretation, the general fit is good. Both low and high-emissions scenarios project losses in the 2050s and 2080s. With the low-emissions scenario, areas of southern and eastern England become unsuitable as well as small areas of southern Wales. R. temporia distributions in the South-West, the Midlands, some of East Anglia and Northern England, Scotland and Wales remain in areas of stable appropriate climate space. In the high-emissions scenario these losses are more widespread with the majority of Southern England, the Midlands, Yorkshire and Wales unsuitable in the 2080s. In this scenario only the far north of England, some of the Yorkshire coast and Scotland maintains stable climate space; gains in climate space are only available in a small section of central northern England and Scotland. For a relatively common species, the widespread loss of future appropriate climate space presented by the high-emissions scenario poses significant concern: the model suggests a reduction of the appropriate spatial range to a very small proportion of northern England. Moreover, the regional-scale losses of appropriate climate space for such a prevalent species by the 2080s in the low-emissions scenario suggest this concern is significant irrespective of emissions scenario.

Figure 3.12 Rana temporaria




emissions Scenarios

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3.2.7. Zootoca vivipara (Common lizard)

For England and Wales, the distribution of appropriate climate space for Zootoca vivipara matches the patchy but relatively prevalent distribution of species presence shown by the NBN maps. There are however some small signs of underestimation in central northern England and more widespread underestimations in central northern Scotland. These underestimations should be taken in consideration when interpreting the gain-loss maps. The low-emission scenarios show patterns of loss of appropriate climate space beginning in south and south west England, the East Midlands and south Wales in the 2020s and 2050s, a pattern that expands to include much of eastern England by the 2080s. However, appropriate climate space remain stable in the remainder of the Midlands and Northern England, some areas of the South West and Wales. Furthermore there are gains in areas of central Northern England and Scotland fill in gaps in the northern distribution of appropriate climate space. As the NBN data shows that Z. vivipara is already present in many of the areas highlighted as a gain it is likely that, in practice, these gains would more likely reflect a general pattern of northern stability of appropriate climate for the species. The losses in appropriate climate space in Southern England suggest the potential for a significant retraction of previously widespread spatial distributions of Z. vivipara as mapped by the NBN with only a few areas in southern and south-western England remaining appropriate in the 2080s.

Figure 3.13 Zootoca vivipara




emissions Scenarios The high-emission scenario projects that the climate of most of southern England, the south west, East Anglia and the southern Midlands will be inappropriate by the 2050s, with midland and northern England becoming unsuitable by the 2080s. The only exception is a small area central

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northern England, where climate space is identified as ‘gained’ but represents an area currently recognised by the NBN maps as supporting a population of Z. vivipara. Although from a UK perspective, Scotland retains some stable and gained climate space under the high-emissions scenario, the small area of central northern England identified above would represent the last bastion of the English distribution of Z. vivipara.

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4. Discussion

4.1. Projected impacts of climate change on herpetofauna

Studies at global and European scales project climate change as presenting both new threats and opportunities for reptile and amphibian species in the future. Hof et al. (2011) performed a global modelling study that produced global maps of the proportion of “frog and toad” and “salamander and newt” species projected to lose climate space in a scenario created from the mean results of 14 GCMs, 3 emission scenarios and 3 modelling algorithms. An interpretation of these maps focussing at the UK scale shows, for “frogs and toads”, a loss of between 30-70% with the cells with the greatest losses in Scotland and to the east. For the “salamanders and newts” class the losses were more severe, with the south of England showing losses of 60-80% of its species. Conversely, Araújo et al. (2006), used a suite of four models, and similar climatic variables to this report, to project expansion and contraction of European amphibian and reptile species Their results suggest that 26% of amphibian species and 44% of reptile species were consistently predicted to expand their distributions, whilst only 5% of amphibian and 5% of reptile species were expected to contract. This expansion is expected to reflect a warming in the cooler northern ranges providing new opportunities for colonisation. To some extent this is to be expected as herpetofauna are ectothermic, “cold-blooded”, meaning that climate cooling is likely to have more of a direct impact than climate warming. In fact, Araújo and Pearson (2005) argue that at a European scale modern distributions largely follow post-glacial patterns, relatively unaffected by climatic changes since (Araújo & Pearson, 2005). Table 4.1: Overview of future species climate distribution, qualitative terms used describe the proportion of the full 2080s distribution relative to the original distribution. The interpretation focuses on distribution changes in England, not the UK as a whole; where there is gained space in Wales/Scotland the species is marked with a + by the name.

Low-emissions High-emissions

Win/Lose Species (Common Name) Loss Stable Gain Loss Stable Gain

‘Winners’

Bufo bufo (Common toad)+P ↑ ↓ ↑ Natrix natrix (Grass snake) + ↑ ↓ ↑ Lissotriton helveticus (Palmate newt)+ ↓ Epidalea calamita (Natterjack toad)+P ↑ ↓ ↑↑

Mixed Anguis fragilis (Slow-worm+) ↑ ↓↓ ↑ Coronella austriaca (Smooth snake)+P ↑↑ ↓ ↑

Pelophylax lessonae (Pool frog) ↑↑ ↓↓ ↑↑

‘Losers’

Rana temporaria (Common frog)+ ↓ ↑ ↓↓ ↑ Triturus cristatus (Great-crested newt)+P ↓ ↑ ↓↓ ↑ Zootoca vivipara (Common lizard)+ ↓ ↑ ↓↓ ↑ Lissotriton vulgaris (Smooth newt)+ ↓↓ ↑ ↓↓ ↑ Vipera berus (Adder)+P ↓↓ ↑ ↓↓

Unclear1 Lacerta agilis (Sand lizard)1P ↓↓ ↑ ↓↓ ↑ Key: Win/Lose: This is a qualitative measure interpreted from whether the general pattern is one of stability, gain, or of loss, where the two scenarios show different general trends the term mixed is used. A species’ ability to access the new climate space is not taken into consideration. Low/High-emissions: The amount of gain, stability and loss as a proportion of the 2080s distribution for each species in each emissions scenario has been assessed and classified. Blank = absent; x = present in small areas (≈1-10%); X = present in larger areas but not a significant proportion of majority of the distribution (≈10-40%) and XX = the majority of the distribution (>≈40%). Where X is replaced with for stable, ↓ for loss and ↑ for gain. P Priority species +There is additional stable/gained space in Scotland/Wales . 1Caveat : Although excellent at the European scale the sand lizard distribution for the UK is very poorly matched by the modelling. The results should be interpreted carefully, perhaps with reference to the smooth snake distribution which relies on a similar habitat/climate.











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Table 4.1 summarises the findings of the climate envelope modelling from the perspective of gains and losses of available climate space within England. Under the low-emissions scenario, many of the herpetofauna are seen to be stable or expanding their ranges in the manner identified by Araújo et al. (2006): nine of the thirteen English species modelled are projected to have significant proportions of stable climate space in 2080 or gain significant amounts of additional potential climate space. Of the modelled species it is only the common lizard, smooth newt and adder who lose significant amounts of space in the low-emissions secnario2. Conversely, similar to the findings of Hof et al. (2011) there are only four English herpetofauna (B. bufo, E. calamita, L. helveticus and N. natrix) that retain large areas of stable climate space and gain new potential space under both low and high-emissions scenarios. Instead, the majority of species are projected to suffer significant losses of climate space. The most severely impacted are the common lizard, the smooth newt and the adder, which are projected to lose significant proportions of their climate space in both of the emissions scenarios, and the common frog, great crested newt, slow worm and pool frog that are projected to lose significant proportions of their distributions under the high-emissions scenario. Beyond climate change: wider considerations The species presented in Table 4.1 have been sorted in order of increasing vulnerability to climate change, as indicated by the results of the climate envelope modelling. Preference has been given to sites with greater stability, then by smallest losses, and finally to greatest gains. This reflects the fact that stable distributions are most likely to be the most climatically robust, and those that gain space may not necessarily be able to access this gained space. This must always be taken into consideration when interpreting the findings of this report. Even where the models identify potential climatically suitable space to act as a corridor for species to access any gained climate space from their current distribution there may not be the habitat connectivity to allow natural migration or the species may lack the dispersal capability to migrate with sufficient speed. Furthermore, many amphibian and reptile species are highly philopatric, and are reluctant to move from their original birthing areas (Sinsch, 1991, Blaustein et al., 1994). The findings presented here support the gains in herpetofauna climate space resulting from climate warming identified by Araújo et al. (2006) at the European scale. Many of the species show the greatest stability, and most significant gains in available climate space to be in the North of England and Scotland. In the context of devolution it is clear that when considering adaptation strategies, English agencies looking to safeguard the long term survival of these species will need to work closely with Scottish Natural Heritage and the Scottish Environmental Protection Agency. For some species, such as the smooth newt (L. vulgaris), the great crested newt (T. cristatus), the viper (V. berus) and the common lizard (Z. vivipara), it may well be Scotland that will need to provide the last bastion of the UK’s species distribution, particularly under a high-emissions scenario. The patterns of loss in the south of England identified by Hof et al. (2011), match similar losses identified for a number of species (e.g. R. temporaria, T. cristatus, Z. vivipara) particularly under high-deposition conditions (B. bufo, C. austriaca, E. calamita, L. helveticus, N. natrix). However, the patterns of loss identified in Scotland match neither our findings nor those of Araújo et al. (2006). As the Hof et al. (2011) data are results of a global analysis at a very coarse resolution, it is likely that this is the reason for the difference, and raise a warning for the overinterpretation of highly aggregated spatial data. In addition to climate change, Hof et al. (2011) investigate the threats from land-use change and infection by chytridiomycosis. They achieved this by overlaying the top 25% of global gridcells modelled to a) lose climatic suitability b) have occurrence of chytridiomycosis and c) to have land use change from natural to anthropogenic state. The results showed that whilst climate change posed a threat to “salamanders and newts” in some areas of southern England, the greater threat was posed by

2 The results for the sand lizard (L. agilis) also show severe impacts of climate change, with significant losses of climate space. However the projected climate space map for baseline matches the current distribution so poorly that it is unwise to draw conclusions from this modelling.

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chytridiomycosis. The global scale of analysis, and the coarse spatial resolution of the study suggests that the results should be interpreted cautiously at a country scale. However, it is clear that adaptation strategies for climate change cannot be taken in isolation and factors such as disease and land use change must also be considered. Further considerations also include a holistic understanding of the interactions between the reptile and amphibian species to be conserved. Competition and predation are real issues, and management options that produce suitable conditions for one species may lead to conditions where that species outcompetes another. Changes in habitat structure that favour the common toad, for example, (Denton et al., 1997) can lead to its tadpoles outcompeting those of the natterjack toad as they breed earlier (Banks and Beebee, 1987a; Griffiths, 1991). Similarly, conservation and translocation options need to reflect the particular requirements of individual species. The reproductive success of the natterjack toads, for example, can also be affected by the presence of predators or infections. It has between shown that such toads discriminate against ponds with a high number of competing species, such as common toad and common frog larvae (Banks and Beebee, 1987b). The predation of tadpoles by invertebrates, including dytiscid water beetles, Notonecta species, Odonata larvae and the great crested newt, can also lead to mortality during the developmental phase. Similarly, conservation or adaptation options for the great crested newt need to take into consideration fish numbers and fish stocking considerations, as the newts actively avoid sites with fish populations (Cooke and Frazer, 1976, Denoël and Ficetola, 2009). 4.2. Managing the changing patterns of British Herpetofauna: implications for policy and practice

Many of the adaptation actions identified for particular species are already part of conservation practice, but climate change will lead to particular challenges where it becomes unsuitable in current parts of a species’ range and also where new areas become climatically suitable. In the former, reducing other pressures (Smithers et al., 2008) will be particularly important, along with ensuring that the habitat is in good condition. These can be aided by agri-environment schemes and the Water Framework Directive, along with actions for species and habitats under the UK Biodiversity Action Plans. Newer opportunities for integrating conservation and adaptation into wider scale planning and management include biodiversity offsetting and habitat banking. The implementation of the UK Natural Environment White Paper[1] should provide a framework for some of these actions and the Lawton Review (Lawton, 2010), which recommended that we need more and bigger areas for conservation, that are better connected will both help to support many of the identified adaptation actions. Key challenges are perhaps achieving the requisite integrated cross-sectoral working to manage some of the current threats and to ensure the availability of suitable future habitat in new areas, alongside assisting species movement, either directly through translocation or indirectly through landscape scale habitat management. Questions may also need to be asked about for how long should we go on expending resources in areas where climate space becomes unsuitable in the future.

4.3. Understanding the future of British herpetofauna: identifying future research needs

The previous sections have addressed in detail objectives 1-3 of this report. The final objectives were objective 4: to determine how the approach can be used for modelling for all herpetofauna species; this is discussed in section 4.3.1 and objective 5: to identify targets for future research; this is discussed in section 4.3.2 4.3.1. Expanding the modelling approach to all herpetofauna species

We were able, as part of this present work, to model not only the six priority species, but all thirteen reptile and amphibian species native to England (including the recently re-introduced native pool

[1] http://www.defra.gov.uk/environment/natural/whitepaper/

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frog). As this list is comprehensive at the UK scale, there are a number of areas on which future modelling could focus. 1) Alien/Naturalised species There are a number of alien or naturalised species already present in populations within the Uk, some of which pose a threat to English native species. Climate-space modelling could help to determine whether these populations will have opportunities to grow or are likely to die out, providing a basis for a discussion of their future. Alien, “neglected native” and naturalised species include:

• the alpine newt (Triturus alpestris); • marsh, edible, bull and European tree frogs (Rana ribibunda, R. esculenta, Lithobates

catesbeianus and Hyla arborea); • fire-bellied, midwife, clawed toads (Bombina spp., Alytes obstetricians and Xenopus laevis), • wall and green lizards (Podarcis muralis and Lacerta viridis); • the Aesculapian snake (Elaphe longissima).

2) European species It would also be possible to explore the projected available climate space for northern Europeanherpetofauna, particularly those close to the channel, that risk losing their available climate space on the mainland and for which England and the UK in general may prove to be a last bastion of appropriate European climate space. The SPECIES model would allow conservationists the opportunity to explore whether this was the case, and if so which areas of the UK would be most likely to become climatically appropriate and when. Species such as the agile frog (Rana dalmatina), whose British Isles distribution is currently restricted to Jersey may be worthy of consideration (DWCT, 2001). The whip snake (Hierophis viridiflavus), with a current distribution across much of northern france, is another example. Climate modelling from the BRANCH project (Berry et al., 2007) suggested that it in many of the projected futures Britain may become an appropriate habitat; UK based projection could confirm where. 3) Lost “native” species Both the moor frog (Rana arvalis), whose current distribution stretches from lowland Europe to Siberia, and the agile frog have been shown to have existed in England c. 600-695 AD when they became extinct due to anthropogenic change (Gleed-Owen, 2000). With the reintroduced pool frog now being accepted as “native” these species could also be considered for climate space modelling. 4.3.2. Identifying future research needs

The findings of this report provide a preliminary exploration of the potential impacts of climate change on English herpetofauna. There are, however, many opportunities to build on this research to further build our understanding, and improve our management England’s reptiles and amphibians. Explore the use of nested input data for the UK

For a number of species, most notably the sand lizard, the mismatch between the projections based on European data with the NBN data at the British scale reduced the possibility of interpreting future changes. Studies have shown that networks with projections that better match raw data can be created by following a nested approach where UK and European species and climate data are used to train the networks (Berry et al., 2007b). This approach could be considered for further studies. Update the climate data

UKCIP09 scenario data is available and presents data for three emissions scenarios (low, medium and high). However unlike the UKCIP02 data it uses a probabilistic approach; the user selects a probability level, such as 90%, and data is provided for each spatial cell as to the temperature for that cell that there is a 90% chance of being equal to or lower. As such, deciding which datasets to use to

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train the networks would require some careful thought and a suite of datasets would probably be needed to make the most of the advantages offered, including capturing more of the uncertainty associated with climate projections (UKCIP, 2009). Vulnerability analysis

By quantifying the proportions of total distribution, gain, loss and stable climate space vulnerability indices for each species can be explored to provide measures of vulnerability (Berry et al., 2007b). Performing this analysis at a country level can help to strengthen the preliminary indicative analysis performed in Table 4.1. Regional analysis could also be performed, but would need to use relatively large regions (perhaps four or five) given the uncertainties associated with both the modelling and the climate itself. However, a regional scale analysis may help to further elucidate inter-regional differences, and highlight management priorities. If combined with sensitivity testing to illuminate the influence of individual climate variables on species vulnerability a greater level of understanding of potential drivers of herpetofauna change could result. Explore wider factors affecting species distributions:

The work presented here provides an excellent building block for exploring which factors such as connectivity and habitat also play a role in determining species’ ability to access future climate space. A follow up modelling study that integrates habitat data and explores connectivity might offer further insight to support the conservation and management of reptile and amphibian species. Similarly the inclusion of predator, pest and disease information would lead to a more holistic analysis. Explore holistic management:

Informed management decisions are best made when they include information from a variety of sources, disciplines, methodologies and viewpoints. The projected climate space presented here is a first step towards understanding the potential impacts of climate on herpetofauna. Further research with an interdisciplinary team including bio-climatic modellers, herpetological experts, land managers (farmers, foresters, coastal dune and heathland managers), environmental managers, interested NGOs and policy makers, would encourage knowledge exchange in a way that will ultimately frame future research to ensure it tackles the real needs of herpetofauna in both policy and practice. 5. Conclusion

Climate change poses a significant threat to many British reptile and amphibian species. Only four of the thirteen species are projected to have stable ranges in both low and high deposition scenarios. Whilst an improving climate often projects new climatically appropriate spaces in the northern areas of England, issues such as connectivity, and ease of movement may limit many species’ ability to adapt. A number of potential adaptation options have been suggested, and links with policy mechanisms highlighted. Happily, many of the options best placed to address climate change, are already known and recognised as “best conservation practice”. However, both the scale of the potential impacts of climate change on herpetofauna, and the complexity of the interactions between habitats and between herpetofauna themselves is significant. Conservation approaches need to take into consideration the fact that positive management for some species may have detrimental management on others (cf. smooth snake and sand lizard) and that some protected species prey on others (cf. natterjack toad and slow worms). Careful, well considered, holistic planning which takes a long-term view will be needed to address this complexity. To achieve it, there will be a need to involve a wide cross-section of governmental bodies and interested parties and include representatives from a variety of sectors (e.g. agriculture, development, planning, environment) both in England and in the wider UK. The approaches taken will need to focus on simultaneously protecting herpetofauna against existing threats whilst ensuring that the protection provided is robust against any potential adverse impacts of climate change and the changing spatial patterns of appropriate climate-space.

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