Ruth's HerpetoArea GB by

Theme 2, Assess the problem - phrasing the question

ruthchambers5 — 2019-02-26 16:29:57 UTC

Re-writing the 1st para of the question slightly:
A. There is strong evidence, that during the last million years the Earth underwent several very cold periods (glacial periods) transforming into cooler intervals (interglacial periods).
B. In Europe, all three peninsulas, the Iberian, the Italian and the Balkan one, have high numbers of endemic species whereas endemism in northern European areas is practically non-existent.

So, the question to be answered can be phrased: How might A (long-term climate changes), affect B (geographical distribution of species richness)?

Theme 2, Assess the problem - possible answers

ruthchambers5 — 2019-02-26 16:33:36 UTC

How might A (long-term climate changes), affect B (geographical distribution of species richness)?
My (quite basic) thoughts are:

Some species will go extinct as glaciation expands, depending on their mobility, i.e. physical ability to extend their range southwards to remaining warmer areas. Birds and flying insects might be expected to be most mobile.
Looking at trophic links and climate, a factor influencing survival of fauna will be whether predators and prey species migrate “in tandem”, or whether predators can adapt to different prey already inhabiting habitats in warmer latitudes (or herbivores can adapt to different vegetation types here).
Physiological adaptation to cooler conditions could evolve for some species which cannot migrate during the periods of glaciation.
Endemism is likely a result of southern peninsulas becoming refuges from colder conditions during glaciation, with species richness favoured by a) migration of species north-to-south to inhabit the areas with milder climate, and b) evolution of both extant southern populations and migrant populations, as they become isolated here as glaciation covers the north.

Theme 2, Assess the problem - key thought

ruthchambers5 — 2019-02-26 16:38:17 UTC

I am not sure which of the five climate change responses of animals has most effect on biodiversity distribution, but I think argument no.2 (i.e. animal migration) is likely to be a predominant influence.

Theme 1 - Local herp habitats

ruthchambers5 — 2019-03-04 11:07:49 UTC

County Durham, Hedleyhope Fell Nature Reserve
Hedleyhope Fell is one of the largest mid-altitude heathlands remaining in County Durham. The land is owned and managed by the Durham Wildlife Trust, a charitable organisation.
Habitats comprise a mosaic of heather, bilberry, acid grassland, rush pasture, bracken beds, patches of gorse and scattered trees. Common Lizard (Zootoca vivipara), Adder (Vipera berus) and Slow Worm (Anguis fragilis) occur.
The Fell covers c.200 ha. Although large, it is an isolated habitat, bounded on all side by agricultural (grazing) land. It lies at altitude of 266m above sea level, midway between lowland coastal regions to the east, and higher moorlands (400m and above) in the west of the county.
Source: https://durhamwt.com/reserves/hedleyhope-fell-nature-reserve/

Theme 1 - Local herp habitats

ruthchambers5 — 2019-03-04 11:28:42 UTC

County Durham, Hamsterley Forest
This forest is publicly owned by the UK's forest authority, Forestry Commission, and is actively managed for timber production. Public access and recreation is encouraged, and there are remnants of habitats which occurred prior to afforestation, which have been conserved in the woodland mosaic. These include ponds, such as the one pictured, which support amphibians, most frequently Common Frog (Rana temporaria) and Common Toad (Bufo bufo). Palmate Newts (Lissotriton helveticus) are also likely to be present, being most common in the county in slightly acid upland ponds.
Source: https://www.arguk.org/info-advice/arg-herpetofauna-county-atlas/249-amphibian-atlas-of-north-east-england-2016/file

Theme 1 - Local herp habitats

ruthchambers5 — 2019-03-04 13:24:26 UTC

County Durham, Crowtrees Local Nature Reserve
This reserve is nationally important for its grassland communities, which grow on a rare outcrop of rock type (Magnesian limestone). The land is owned by the County Council and is legally protected.
Several ponds are present, formed by subsidence owing to past mining for sand and limestone.
The ponds support Common Frog, Common Toad, Smooth Newt (Lissotriton vulgaris) and Great Crested Newt (Triturus cistatus). The Great Crested Newt population is substantial - in 2018 c.200 newts were recorded.
Source: https://www.durham.gov.uk/media/3990/Crowtrees-Nature-Reserve/pdf/CrowtreesNatureReserve.pdf

Theme 1 - Location of herp habitats in County Durham, UK

ruthchambers5 — 2019-03-04 13:47:09 UTC

Theme 1 - ID card for local amphibian fossil

ruthchambers5 — 2019-03-04 14:37:49 UTC

Name: Kyrinion martilli
Taxonomic Group:
Kingdom Animalia

Phylum Chordata

Class Amphibia
Type status: Holotype
Location / date found: Whitley Bay, Tyne & Wear, 1993
Geological Age: Carboniferous (310 – 312 Ma B.P.)
Specimen Type: Skull
Museum: Great North Museum, Newcastle-upon-Tyne
Source: http://www.3d-fossils.ac.uk/fossilType.cfm?typSampleId=25000869

Theme 1 - ID card for local reptile fossil

ruthchambers5 — 2019-03-04 14:51:38 UTC

Name:
Taxonomic Group:
Kingdom Animalia

Phylum Chordata

Class Reptilia
Type Status: Holotype
Location / date found: Middridge, County Durham, 1866
Geological Age: Permian Period (252.2 – 298.9 Ma B.P.)
Museum: Great North Museum, Newcastle-upon-Tyne
Source: http://www.3d-fossils.ac.uk/fossilType.cfm?typSampleId=25000762

Theme 1 - Phylogenetic tree for fossils

ruthchambers5 — 2019-03-04 15:01:48 UTC

I have used this image of a phylogenetic tree as it usefully indicates geological periods in the evolution of vertebrates. The vertical red lines indicate the periods to which the amphibian and reptile fossils above have been dated, i.e. respectively, Carboniferous and Permian.
Source of diagram (image by David Lin): https://manoa.hawaii.edu/exploringourfluidearth/media_colorbox/3458/media_original/en

Amphibians and Reptiles in the UK

ruthchambers5 — 2019-03-04 15:27:20 UTC

We have 13 native species of reptile and amphibians in the UK, alongside several non-native species. The native fauna are listed below, with those occurring in the NE of England (9 species) marked in bold:

three species of snake - adder, smooth snake (Coronella austriaca) and grass snake (this species is thought probably to have become extinct in NE England in recent years)
three lizard species - common lizard , sand lizard (Lacerta agilis), slow worm
two toad species - common toad, natterjack toad Epidalea calamita
two frog species - common frog, pool frog Pelophylax lessonae (reintroduced)
three newt species - palmate newt, smooth newt, great-crested newt

The herpetofauna of the UK is quite limited compared with most other European countries. This is largely due to the fact that Britain was glaciated for most of the time that it was connected to the European mainland, and following the retreat of the ice sheet there were only a few thousand years before the English Channel separated Britain from the European continent (about 8,000 years ago). As a result there are no endemic reptiles or amphibians in the UK, and the species we have are those cold-tolerant ones that already inhabited northern Europe prior to the formation of the English Channel.

Amphibian Species in NE England

ruthchambers5 — 2019-03-04 15:27:54 UTC

All five NE species are quite widespread, the most frequent being the Common Frog, and the least frequent the legally protected Great Crested Newt. All are declining in numbers.
All five species use mainly natural or semi-natural terrestrial habitats and breed in still, fairly neutral pH waters, including garden ponds. Frog and toad tadpoles can survive on plant material such as algae, though they will also eat animals. Newt larvae - known as 'efts' - will only eat invertebrate animal material.
Amphibians are regularly surveyed for, so there are many reliable records for these species.
Source: http://www.nhsn.ncl.ac.uk/interests/reptiles-amphibians/amphibians/

Physio-ecological Profile of European Adder

ruthchambers5 — 2019-03-04 15:29:19 UTC

The UK's only venomous snake
Hinged fangs to inject venom into prey
Average adult length 50-60cm (max 80cm)
Sexual dimorphism in size and colouration - females generally heavier and reddish with brown markings, compared to usual pale grey/ cream of males with dark markings
Viviparous - eggs incubated internally and live young produced
5-6 year lifespan in wild in NE England
Diet - mainly small mammals, plus frogs, lizards, small birds
Habitat - wide variety but almost always on chalk / sandy soils, i.e. moorland (low / mid altitude), grassland, woodland edge, coastal dunes, disused quarries; needs combination of dense vegetation cover and open ground for basking
Activity - diurnal (may be active at night during hot weather)

Other specific aspects of Adder physiology / ecology in more detail...

Habitat features for reproduction / hibernation - Hibernacula play a very important role in the seasonal movements and reproductive cycle of adders. In northern latitudes, adders generally hibernate (often communally) from November to March. Males emerge first, then spend a substantial time basking - maybe several weeks - often very close to the hibernation site. This period of lying out is followed by sloughing, after which the males become much more active, competing for females and eventually mating. The gestation period is approximately 3 to 4 months. Female adders retain their eggs within the body and give birth to 3-18 live young during August and September. Adders return to traditional hibernation sites in late summer, and often this is also where the females give birth. The young are born with fat reserves to aid them in survival until the end of hibernation.

Since adders’ are ectothermic, they are physiologically dependent on available habitat features to help them regulate their body temperature and hence sustain or moderate their activity levels seasonally, i.e. dry, open areas are needed for basking to help raise metabolism and allow courtship, breeding, hunting in spring, while sheltered, subterranean refuges are needed in winter to ensure body temperature is maintained above freezing during hibernation.

Although some adders can move over distances of up to 2km through the year, other animals may move no more than a few tens of metres around their preferred hibernation site. This high degree of site fidelity is one reason why hibernation and birthing sites are critical to managing habitat for adders.

Sources:

Melanism - In addition to the usual distinctive colouration of adders, melanistic (black) individuals can occur in some populations. The usual argument for the maintenance of melanistic forms (morphs) in the wild is that they may be more successful than the 'zigzag' morph as their darkened skin cells means that they have a thermoregulatory advantage by warming up quicker. Black individuals can therefore feed on days which would be too cold for other individuals.

Some studies have found that melanistic males were heavier than
normal coloured males of the same length, and this in turn conferred an advantage during male sexual combat for mates (i.e. larger snakes won). It was postulated that the melanistic morph may be thermoregulatorily favoured particularly during periods with unstable or colder climate. However, experiments suggested that these advantages can be offset by black snakes being more visible and hence at an an increased risk of being discovered and eaten by predators compared to the normal-coloured specimens, which are better camouflaged.

Other studies have shown no size difference between black and zigzag colour forms, so further studies are required to test the above hypothesis.
Sources:

Photo - Rare finding of male, female and melanistic adder together, in Dorset UK, 2015

Physio-ecological Profile of Great Crested Newt

ruthchambers5 — 2019-03-04 15:29:27 UTC

UK's largest newt species, males up to 15cm in length, females reaching 18cm
Terrestrial for most of the year, living in varied habitats usually within 500m of favoured breeding ponds
Move to wetland breeding habitats March to July, tending to remain here after courtship and feed on aquatic prey (compared to other newt species which leave ponds sooner after breeding)
Bottom-dwelling while in ponds, prey include leeches, water beetles, insect larvae, tadpoles, occasionally Smooth Newts
Movement over land to breeding ponds occurs at night
Hibernate from October - to late February, in areas protected from flooding and frost, e.g. leaf / log piles, crevices in stumps or walls
Adults can live up to 15 years but most survive only several years after sexual maturity (2-4 years)

Other specific aspects of Great Crested Newt physiology / ecology in more detail...

Factors affecting breeding migration - Being ectothermic, newts activity cycles are governed by environmental temperatures. Adult great crested newts normally begin moving from their over-wintering land sites between February and April, and the timing of this movement is governed particularly by temperature and rainfall. The first of the newt emergence nights are normally wet or damp, with air

temperatures above 4 - 5°C, following several days when the temperature has been just below this level. This makes it less likely that newts will be stimulated to emerge too early by a single unseasonably warm winter’s day, only to then find themselves above ground or in the water when freezing conditions return.
Movement exclusively at night, and generally in wet conditions, may also reduce the risk of dehydration, given the permeability of the newt's skin.
Sources:

Egg-laying behaviour - A breeding female Great Crested Newt will lay about 250 eggs per season, each egg individually deposited, typically on the submerged leaf of a marginal plant, under water and often close to the surface. The hind legs and feet are used to wrap the leaf around the egg, which is surrounded by an adhesive substance ensuring that the leaf encloses and protects it. A wide range of plants with thin and easily folded leaves are used for egg-laying, such as grasses and other narrow leaves, and small wide-leaved plants.
Also, eggs are sometimes laid in folded dead or decomposing leaves, from the previous year’s growth or terrestrial plants whose leaves dip into the water. Sometimes eggs are left on the surface of leaves, on stalks, algae, old logs, roots and stones and debris such as plastic bags.

Reasons for egg-wrapping have been studied in the context of it being a potential anti-predator strategy. One experimental study found that predatory newts (especially females) and water beetles when presented with wrapped and unwrapped eggs, ate fewer wrapped eggs. Egg-wrapping may also help to control temperature conditions for embryo development (duration of embryo development increases when water temperature decreases).
Sources:

Native Amphibians of NE England - Photos

ruthchambers5 — 2019-03-05 09:56:04 UTC

All newts shown are adult males in breeding condition. Outside the breeding season both males and females lose characteristic features (e.g. crests, spotting) which help in identification, and, as there is a lot of variability in individual colouration, non-breeding animals are more difficult to identify to species.

Distribution of Newt Species in NE England

ruthchambers5 — 2019-03-05 10:19:35 UTC

The Great Crested Newt is known from around 800 ponds in the region, mainly in eastern lowland areas, but occasionally on higher ground in more western areas, particularly in limestone quarries.
Great Crested Newts are well recorded because of their legal status (where developments require planning permission, surveys of nearby ponds for amphibians must be conducted).
The Smooth Newt is the commonest newt in the lowlands of NE England, whereas the Palmate Newt is mostly an upland, and western, species in the region.
Records from 2000 onwards are dark green squares, 1990 to 1999 are lighter green, and earlier records are yellow.
Source: Durkin, J. (2016) Amphibian Atlas of NE England 2016. North East Reptile & Amphibian Group.

Reptile Species in NE England

ruthchambers5 — 2019-03-05 10:19:40 UTC

The two snakes, Adder and Grass Snake , and two lizards, Slow Worm and Common Lizard, found in NE England are not widespread in the region, and populations of all are declining.
All are restricted to predominantly upland habitats. Adders, Slow Worms and Common Lizards are often found in the same locations. The Common Lizard is the most frequent and well distributed. The Grass Snake, which is at its northern limit here, is much the rarest and the most local, and lack of recent records along with habitat deterioration in known sites suggest it may now be extinct in the region.
Preferred habitats for Common Lizard, Adder and Slow Worm is the moorland edge, where there is varied topography including rocky stream banks, disused quarries and dry stone walls. In lowland areas of the NE suitable habitats are more scarce and fragmented.
Source: http://www.nhsn.ncl.ac.uk/interests/reptiles-amphibians/reptiles/

Native Reptiles of NE England - Photos

ruthchambers5 — 2019-03-05 11:22:28 UTC

Adders' background colour varies from grey-white in the male to shades of brown or copper in the female. Young adders are copper, light brown or reddish, with darker brown markings. Completely black adders occur in some areas.
Common Lizards are commonly a shade of brown with patterns of spots or stripe, but colour variants are not uncommon - everything from yellow through various shades of green to jet black.
Slow Worms are legless lizards, having a shiny appearance, with males being greyish brown and females brown with dark sides.
Grass snakes are more slender than adders, and have a distinctive collar. They are Britain's only egg-laying snake.

Distribution of Reptiles in NE England

ruthchambers5 — 2019-03-05 11:51:13 UTC

Distributions of Adder, Common Lizard and Slow Worm in NE England are shown below. Records from 2000 onwards are dark green squares, 1990 to 1999 are lighter green, and earlier records are yellow. The Grass Snake's fate in our region is discussed in detail later.
Source: Durkin, J. (2016). Reptile Atlas of North East England, 2016. North East Reptile & Amphibian Group.

Theme 4, Assess the problem

ruthchambers5 — 2019-03-11 12:17:21 UTC

"Politicians, scientists, civil society as well as the public could propose possible strategies for the conservation and sustainability of Malagasy reptiles. Take on a role (politician, scientist or civil society) that fits your personality the best, and start building on a proposal!"

Of course, to be effective, politicians, scientists and public groups must ideally act together to respond to the needs of herpetofauna conservation. So, although I have chosen civil society as the role for which I’m describing actions, the measures listed will interlock with other actors and their concerns. I’m assuming that civil society here refers to groups based in local centres in the country (perhaps affiliated to a national conservation NGO), interested in nature conservation.

Seek advice from scientists / agriculturists about alternatives to existing farming practices which damage reptile habitats.
Prepare educational resources on threatened reptiles of Madagascar, and the benefits of conserving them and their habitats, and biodiversity in general. Work in local communities, with agreement of local authorities, to distribute these resources and make direct contact with farmers and schools to talk about how they can help conserve reptiles.
Lobby local and national politicians to request they take action to support reptile conservation (e.g. enforce custom restrictions on trade in tortoise specimens, change economic / agricultural policy to favour forest conservation, ensure sufficient resources to police and manage protected areas).
Organise citizen science projects to help record species occurrence and impacts at a local level (e.g. in priority areas for conservation).
Work with international NGOs to advise them of local problems and social issues in reptile conservation and encourage direction of resources to these problems (e.g. poverty in farming communities resulting in habitat degradation).

Design the business plan of a voluntary organisation which aims to protect the local herpetofauna

ruthchambers5 — 2019-03-13 10:43:46 UTC

Contents of Business Plan

Purpose of the Plan
Identification of Threats to Herpetofauna
Conservation Targets
Activities to achieve Targets

1. Purpose of Plan

ruthchambers5 — 2019-03-13 16:04:35 UTC

Which species (sp or spp) to be considered?
Set priority species, by selecting those which:
- have undergone known declines in numbers; and/or are under-recorded; and/or are legally protected.
Species selected: four species of reptile – adder, grass snake, slow worm and common lizard; and great crested newt.
What area is covered by the Plan? Our local region, i.e. County Durham.
Identification of species' current populations and distribution. See data from 2016 Atlases (Theme 2).

2. Identification of Threats to Herpetofauna

ruthchambers5 — 2019-03-13 16:08:45 UTC

REPTILES

Habitat loss and modification:

Heather moor management involving burning is likely to threaten populations of reptiles.
Loss of heathland is a direct habitat loss.
Overgrazing or regular strimming of vegetation removes resting and feeding areas.
Overtidying, such as removal of rubble, earth and debris piles removes basking and overwintering sites.
Neglect, or afforestation of suitable sites leads to shading and loss of basking areas.
Infilling or reworking of disused quarries leads to loss of suitable habitat.

Disturbance:

Adders and common lizards, which bask in the open, are intolerant of human disturbance, and may suffer from increased public access to sites.

Poor knowledge of distribution:

All reptile sites, but slow worm sites in particular, may be destroyed unknowingly if there is insufficient data available to developers and ecologists.

GRASS SNAKE

Habitat loss and modification. Grass snakes range over large areas, so habitat or range fragmentation can be a particular problem. Built development, roads or agricultural intensification can all lead to loss of habitat in good grass snake areas. Shading from developing woodland is also a problem at the one known site at Gibside.
Disturbance. Increasing visitor pressure it the one known site at Gibside is a potential threat to Grass Snake as it limits opportunities for feeding and basking.
Loss of egg laying sites. Modern flood control techniques mean that there is much less debris left around riverbanks after flooding. Outdoor manure heaps on farms are now less common, with reduced livestock numbers, and turned over too quickly. Also manure now tends to be stored in inaccessible tanks. Fewer gardeners use open, accessible compost heaps.
Poor knowledge of distribution. Grass snake sites may be destroyed unknowingly if there is insufficient data available to developers and ecologists.

GREAT CRESTED NEWT

Habitat loss due to development, despite legal protection.
Loss of unrecorded populations.
Introduction of fish to ponds.

3. Conservation Targets

ruthchambers5 — 2019-03-13 16:14:19 UTC

REPTILES – Priorities
1. To maintain and enhance populations of native reptiles in the County and where possible expand existing populations through conservation management and site protection.
2. To safeguard all known or historic reptile sites, and ensure their appropriate management.

GRASS SNAKE - Priorities

1. Maintain and enhance populations of native grass snakes in the Durham area.
2. Increase the available area of potential grass snake habitat and ensure that existing habitat is managed appropriately for grass snakes.
3. Develop our knowledge of the distribution and ecology of grass snakes in the Durham area.
4. Increase awareness and understanding of grass snakes and their habitat requirements.

GREAT CRESTED NEWT - Priorities

1. Establish and maintain an understanding of the distribution and status of great crested newts through survey and monitoring.
2. Conserve and maintain existing populations of great crested newts preventing further site loss or fragmentation.
3. Raise awareness of the status and needs of the great crested newt and promote appropriate habitat management.
4. Enhance the range, distribution and viability of existing great crested newt populations through the restoration or creation of open water near existing populations.

4. Activities to achieve Targets

ruthchambers5 — 2019-03-13 16:16:07 UTC

Themes:

Protection and Management of Key Sites
Recording
Education

Site Protection and Management
(all species)
Activities required:

Site identification: collate data on species distribution in County; make list of sites with extant populations (including dates of sitings); visit sites and assess habitat suitablity for herps, and any management requirements to improve habitat quality; determine land ownership / partner organisations involved in site management; assess suitablility of adjacent land for habitat improvement for herp populations; select key sites where habitat management / improvement is a priority for population health, and is feasible.
Site management: identify manpower / equipment needs for habitat management; source management staff (might be landowner / managers, voluntary bodies, wildlife consultancy); determine best timing of management tasks, and seasonal repeat management needs (i.e. short-, medium- and long-term resource / investment implications); determine biological monitoring needs (vegetation status, population sizes); form management plan over suitable timescale (e.g. 1-5 years).
Site protection: appraise existing land use risks to herp populations (e.g. recreational access, illegal access / damaging activities, pollutant inputs from adjacent land, direct / indirect impacts from development proposals); work with landowners / managers to reduce risks; lobby local government to safeguard sites and provide boundary buffer zones in legal plans to prevent habitat fragmentation.

Recording (Grass Snake and Great Crested Newt)
Activities required:

Collate data on species distribution in County: make list of sites with former and extant populations (including dates of sitings); identify sites for priority survey (e.g. sites with no recent records, potentially suitable habitat areas not previously surveyed)
Plan new surveys at selected sites: decide options for survey methods / personnel, assessing costs and funding needs (e.g. collaborate with academic institutions? engage wildlife consultants? organise citizen science survey using trained volunteers?); engage survey coordinator to plan survey timescales and ensure resources seasonally available.
Plan for survey record storage and dissemination: arrange for submission of records to local biological records centres.

Education (all species)
Activities required:

Engage a Herpetofauna Education Officer (HEO)
Liaise with local schools and community groups to organise visits from HEO to make presentations on amphibians and reptiles found in the area
Organise a series of field events for the public, to visit amphibian / reptile habitats in the company of a herpetologist, with chance of encountering animals ‘face to face'
Organise herpetofauna survey training days for volunteers to encourage greater collection of species’ distribution data, especially for under-recorded species
Liaise with local landowners, farmers, public bodies (e.g. water companies, local councils), and developers, to (i) communicate how their activities could affect amphibians / reptiles locally, (ii) show best ways to avoid damaging impacts (e.g. from agricultural pollution, highways management, vegetation control, built development), (iii) encourage adoption of favourable habitat management for herpetofauna on their land (e.g. formation of new wetlands, construction of artificial hibernacula, planting of habitat ‘corridors’ to extend / connect suitable habitats)

Examples of Public Participation in Herpetofauna Conservation

ruthchambers5 — 2019-03-14 13:50:25 UTC

Wildlife charities in the UK have organised imaginative projects to help volunteers get involved in herpetofauna survey and conservation. Here are some examples.

Durham Wildlife Trust - Revealing Reptiles

ruthchambers5 — 2019-03-14 15:23:32 UTC

Project Officer organised teams of trained volunteers over two years to establish verified records of reptiles in the region.

Amphibian and Reptile Conservation - Snakes in the Heather

ruthchambers5 — 2019-03-14 15:27:06 UTC

An ARC-Trust project, to use citizen-science to conduct targeted surveys and improve habitats for the Smooth Snake. It is hoped that the project will raise awareness and “ownership” of reptiles among local communities through the media and events.

Four Counties Wildlife Trust - Great Giddings Newt Trail Project

ruthchambers5 — 2019-03-14 15:31:19 UTC

Great Gidding is small village in Cambridgeshire, central England. It has 20 ponds, and all support the Great Crested Newt, Britain's rarest and protected newt species. Local people have made great effort to sustain and improve the breeding ponds, habitats, and terrestrial habitats, so their village remains famous for this charismatic amphibian! The ponds have been thoroughly surveyed by the local Wildlife Trust, and a Newt Trail and map created for visitors.

Herpetofauna Habitats in County Durham - Extent, Problems and Strategies

ruthchambers5 — 2019-03-27 20:28:46 UTC

In this assignment I’m focusing on two of the key habitats which support the three extant reptiles in County Durham (adder, common lizard and smooth snake) and our five amphibian species. The habitat types are: i) moorland and heath, and ii) small freshwater bodies, mainly ponds. I’ll look at the generic risks to each habitat type, and known instances of damage locally, and the knock-on effects on herpetofauna. Climate change issues and ways to counter habitat degradation are then considered.

Reptile Habitats in County Durham

ruthchambers5 — 2019-03-27 20:30:32 UTC

Adders, slow worms and common lizards are mainly found at moorland and afforested sites, which occur predominantly in the north and west of County Durham. Adders are known from the higher upland moors and some isolated mid-altitude heaths, whereas common lizard and slow worm tend to occur in lower moorland habitat mosaics and valley farmland and marshy areas in summer. The moorland edge – where there is varied topography including rocky stream banks, disused quarries and dry stone walls – is important habitat for all species.

Reptiles in Moorland and Heath

ruthchambers5 — 2019-03-27 20:32:01 UTC

See map at end showing location of heathlands and moorland blanket bog in Co Durham
Moorlands are important components of the Durham landscape, covering extensive areas on the higher ridges and plateaux (300m and above) of the west of the county. Many are of national or international importance for their biodiversity. The key habitat types supported here which are favourable to reptiles, particularly adders, are:

blanket bog (high altitude peatland) and upland wet heath – almost half of the total area
upland dry heath
upland scree and rock habitats
bracken beds
gorse scrub

Networks of heath, grassland, mire and bog are extensive and continuous on the high moorlands, but the landscape and integrity of habitats has long been subject to human influence, by grazing livestock, burning, and in recent centuries the digging of drains (grips) to dry out land for grazing or forestry. Most of the moorland area has also been shaped by management for grouse shooting, involving rotational burning of heather and predator eradication to try and optimise conditions for breeding grouse.

Smaller mid- and low-altitude heathlands on the moorland / lowland fringes are survivors from the more pastoral medieval landscape, having declined in extent over hundreds of years under pressures from development, mining, forestry and agricultural improvement. Though they are fragmented and isolated, they are the last refuges for heathland plants and animals in otherwise intensively managed farmlands. Their role in the surrounding agricultural landscapes has diminished and few are currently grazed or actively managed unless designated as nature reserves. Durham is close to the northern limit of the habitat in Britain, and as such it is relatively rare in the county, with 90% of the area found at just three large sites, at Hedleyhope, Knitsley and Waldridge Fell. These are currently managed, and support a range of habitats suitable for reptiles, including mires, scattered trees and scrub, gorse, bare ground, open water, acid grassland and areas dominated by dwarf ericaceous shrubs (heather) and bracken.

List of threats to reptiles and their habitats in the Durham uplands:

ruthchambers5 — 2019-03-27 20:37:45 UTC

Habitat loss and modification:

Heather moor management involving burning is likely to threaten populations of reptiles, directly through mortality from fire and indirectly through destruction of vegetation mosaics / hibernation sites.
Overgrazing or regular strimming of vegetation removes resting and feeding areas.
Over-tidying, such as removal of rubble, earth and debris piles removes basking and overwintering sites.
Afforestation or neglect allows scrub and tree encroachment, leading to shading and loss of basking areas.
Infilling or reworking of disused quarries leads to loss of suitable habitat.
Fragmentation and disturbance from developments such as access roads and mineral extraction, leads to direct habitat loss.
Nutrient enrichment, especially from intensive livestock farming practices, can change vegetation composition, e.g. favour growth of monocultures of vigorous plants.

Disturbance:

Adders and common lizards, which bask in the open, are intolerant of human disturbance, and may suffer from increased public access to sites, especially where dog-walking is popular.
Intensive recreational pressures, such as mountain biking, trail riding, or organised sports events can disrupt reptiles’ activity patterns and damage basking/hibernation sites.
Use of secluded habitat areas as illegal rubbish dumps can fragment habitats.

Case Study of Threats to Reptile Habitat - Burning of Upland Moorland and Heath

ruthchambers5 — 2019-03-27 20:38:21 UTC

Controlled rotational heather burning in winter is an important management tool on uplands managed for grouse shooting in the UK, its main benefit for the birds being to create a mosaic of heather of different ages - young plants provide new growth for birds to feed on and old plants provide shelter. Removal of accumulated dense woody material in this way can also help reduce the vulnerability of heathland and scrub to accidental uncontrolled deep-burning summer fires, which can be catastrophic for reptiles and other wildlife. However, the winter burning can be equally devastating to reptiles if timed wrongly. The problem is that the burning season lasts until 15^th April, and so often takes place just as adders are emerging from hibernation and are highly vulnerable (i.e. March and April). It is believed that the effect of repeated burning over the last few hundred years has virtually extirpated adder populations from vast areas of upland Britain. The photo of Durham moorland may illustrate this – it shows a patchwork of burnt areas on privately owned moors, over which adder records are rare, and outlined in yellow is public land (Pow Hill Country Park) managed for heath, scrub, woodland and grassland, where a small adder population persists.

Strategy to address this threat:

On a site where adders are known, burning should not be used except under exceptional circumstances and not unless surveys have been carried out beforehand to ensure that important habitat areas are not affected. Where heather burning is the only practical management option, herpetologists advise that it be conducted before the spring emergence period (from January to April, depending on location).

Amphibian Breeding Habitats in County Durham

ruthchambers5 — 2019-03-27 21:20:03 UTC

Summary of Amphibian Distribution
The great crested newt is known from around 800 ponds in NE England, mainly in eastern lowland areas, but occasionally on higher ground in more western areas, particularly in limestone quarries. Upland colonies, at over 300 metres in altitude, are found, but are rare. The smooth newt is the commonest newt in the lowlands of the county, with distribution following the river valleys in the east. By contrast, the palmate newt is mostly an upland, and western, species in the region. Common frog is the most frequently recorded species, distributed widely throughout County Durham. Common toads are also well distributed, being tolerant of slow-flowing waters, but not occurring in highest moorland.

Types of Open Water Habitat Available
In County Durham, there are approximately 1000ha of standing waterbodies, but this area figure refers mainly to large artificial waterbodies, such as reservoirs and other man-made open waters such as quarry pools (e.g. from flooding of gravel pits). Naturally formed waterbodies are fewer in number and area, but include subsidence pools in limestone, cut off river meanders, and (most rare) permanent upland pools.

Occurrence of smaller ponds is poorly documented across the county, but amphibian records suggest they are more common in the eastern lowland river valleys. Generally, a pond is defined as a temporary or permanent water body between 5 square meters and 2ha (5 – 20,000 m²) in surface area, which holds areas of open water for at least part of the year. Suitable amphibian breeding ponds may include village green and garden ponds, amenity lakes, flood control ponds that function as part of urban drainage schemes, farm ponds created for watering stock, or by seepage caused by closure of pumps on agricultural land.

Case Study - The Decline of the Grass Snake in NE England

ruthchambers5 — 2019-03-27 21:27:32 UTC

Grass Snakes are found throughout lowland England and Wales, becoming rarer in the north of England, and absent (except for known introductions) from Scotland.
In NE England Grass Snake records are fewer when compared with other reptiles, but historically the species is known from several location in both counties (Northumberland and Durham) - as shown in the map below.
However, from 2000 onwards, sightings have been almost solely confined to one river valley (Derwent) in County Durham. It now appears that recent, breeding records of Grass Snake are confirmed for only one site in the Derwent Valley, at Gibside, a publicly owned estate with historic landscapes and buildings where year-round recreational use is allowed. However, 2009 was the most recent year when the species was sighted at Gibside, and there is concern that several issues are adversely affecting habitat conditions for snakes on the estate:

increased visitor numbers cause disturbance within habitats, limiting opportunities for snakes to bask and gain access to wetland areas to feed (they prey mostly on amphibians)
developing woodland is shading habitats, reducing areas where snakes can bask
established breeding sites - composting vegetation - need adequate protection so female snakes can return each year to lay eggs undisturbed.

In addition to problems at the last known breeding site, habitat fragmentation in the surrounding lowland countryside means that the full range of habitat features required by Grass Snakes (wetlands for feeding, rotting vegetation for nesting, open areas for basking, rubble piles / mammal burrows for hibernation) are unlikely to be found in past breeding localities.
The most recent survey for Grass Snakes in County Durham was 2017-18, when Durham Wildlife Trust engaged train volunteers in the 'Revealing Reptiles' project, to visit known and potential reptile habitats in the county. No Grass Snakes were recorded over the 2-year survey period.
Sources:

List of threats to amphibians and their wetland habitats in Durham:

ruthchambers5 — 2019-03-28 14:46:51 UTC

Loss of ponds to development can cause direct loss of amphibian breeding habitat.
Destruction of surrounding terrestrial habitat (e.g. scrub, woodland, hedgerows, heath) can also be detrimental even if a pond is undamaged, as it can cause direct loss of over-wintering and foraging sites, plus loss of connectivity between retained and other local ponds which can reduce an area’s potential to maintain species meta-populations.
Natural succession of ponds to dry land communities through build-up of vegetation is not, by itself, a threat to amphibians, unless a pond is an isolated waterbody comprising the only breeding site in a large area. Complexes of several waterbodies at different stages of succession is the ideal situation, but local species losses will result if there is a lack of replacement open water habitats as an older pond dries up. Where ponds are isolated, and where open water is seen as a crucial conservation factor, partial clearance may be necessary.
Point source and diffuse pollution, from both local drainage and run-off from outside the catchment, are a serious threat to amphibian populations, both directly (through direct uptake from water or ingestion of contaminants in soils, sediments, and food items), and via mortality of prey species. Pollution sources can include abandoned mine discharges, sedimentary run-off, atmospheric deposition, and pesticide loads and nutrient enrichment from agricultural run-off.
Fish stocking of ponds can affect wildlife through competition, introduction of diseases and invasive plant species. Newts in particular suffer from predation of eggs and larvae by fish.
Increases in recreational activity around ponds can lead to increased littering, degradation of banks, and pressure to control aquatic plants, which can all affect amphibians’ ability to move between waterbodies and terrestrial habitats.

_{The invasive alien plant Water Fern (}_{Azolla filiculoides}_{) covering a golf course pond}

Case Study of Threats to Amphibian Habitat - Route of Proposed Relief Road

ruthchambers5 — 2019-03-28 15:38:27 UTC

In my local area , a few miles from my town of Durham, the local Council are proposing to route a new road through agricultural fields and a wooded river valley. Six freshwater ponds are present on the field margins, and fieldwork was carried out to assess whether the ponds support amphibian populations. The survey results showed three ponds supported amphibians, with common frog present in all three, and toads additionally in one other pond, and the largest pond supporting additionally smooth newt and great crested newt (GCN).

The map of the pond locations and road route indicates that the new road would destroy one amphibian pond and create a barrier between three other ponds which are likely to support metapopulations of species, including great crested newt. Since great crested newt is protected under the Habitats Directive and under UK law, the usual mitigation for such development impacts is to require developers to create compensatory new ponds and terrestrial habitat within the design process of the road, and translocate newts to these habitats prior to construction works. But research shows that post-development newt numbers often decline compared to those recorded from original ponds, and the long-term viability of translocated populations appears limited.

Strategy to address this threat:
A new approach to great crested newt conservation is being trialed by local authorities in the Midlands of England, based on 'district licences'. These are granted to borough and city councils to allow them to survey land to create maps of GCN habitat suitability over their entire authority area, and identify priority zones where the creation of management of newt habitat would most benefit the newts at the landscape scale. The idea is to promote investment in construction of clean, unpolluted, ponds and good quality terrestrial habitat, which can support and expand existing metapopulations . Developers and landowners contribute to the District License fund at a pre-development stage, so ensuring that they only invest in habitat creation in areas where it is known it will be most beneficial.

Climate change impacts on herpetofauna habitats: Heaths / Moors and Ponds

ruthchambers5 — 2019-03-28 16:09:21 UTC

The potential extent of climate change in the north east has been modelled by the UK Climate Impacts Programme (UKCIP), based on projections of likely greenhouse gas emissions under different global development scenarios. Some of their findings have been published by Sustainability North East (2002). The predictions for 2080 (expressed as ranges from a best-case scenario of concerted global action vs. a worst-case scenario of no action) include:

> annual mean temperatures of 1.5°c - 4.0°c
> winter mean temperatures of 1.0°c - 3.0°c
> summer mean temperatures of 1.5°c - 4.5°c
> winter precipitation of 10% - 28%
< summer precipitation of -18% to -45%
< winter snowfall of 40% - 100%
a rise in sea level of 6cm - 66cm
an increase in the thermal growing season of 40 - 100 days

These changes would bring milder, wetter winters with fewer frosts and little snow, hotter, drier summers, an increase in extreme events like flooding, and increased coastal erosion.

Impacts on Moors / Heaths
The potential impacts of climate change on upland landscapes are not entirely clear. Increases in temperature are likely to lead to greater decomposition of peat, the decline of blanket bog and an increased risk of fire damage, which would be a direct risk to reptile species. Warm late winter / spring temperature may also contribute to local extinctions of moorland reptiles due to restricting animals' activity patterns at crucial emergence and breeding seasons.

Possible ways to mitigate climate change effects on moorland ecosystems are to improve water retention by blocking drains and controlling tree encroachment, and using controlled grazing rather than burning to maintain vegetation mosaics. Restoring connectivity between isolated habitats at a landscape scale may increase the ability of reptiles to move in response to changing conditions.

Impacts on Ponds
Research on lowland ponds in the UK shows that 25% are variable open water habitats, depending on rainfall, i.e. drying out in drier years, but remaining wet in years with higher rainfall. Also, a large proportion of ponds are shallow and prone to natural infill to terrestrial habitats over a short timescale.

In light of this, the main concerns about the impact of climate change on ponds as amphibian habitat are twofold: (i) that the number of permanent pond habitats is reduced because dry years dominate climate patterns and, potentially more significantly, (ii) that climate shifts and weather extremes increase the rates of local extinctions in ponds, in turn reducing richness of remaining ponds further because, in many areas, there are few near-by open water sources for recolonisation.

The creation of new ponds has the potential to help combat some of this loss, both by providing new permanent and semi-permanent freshwater habitats, and creating ‘stepping stones’ to enable freshwater species to move across the landscape.

References and Web Sources

ruthchambers5 — 2019-03-29 15:15:13 UTC

References

Durham County Council, 2008. County Durham Landscape Strategy.

http://www.durhamlandscape.info/article/10136/Moors-and-Heath

Durkin, J. 2016. Amphibian Atlas of NE England 2016. North East Reptile & Amphibian Group.

Durkin, J. 2016. Reptile Atlas of North East England, 2016. North East Reptile & Amphibian Group

European Pond Conservation Network. 2008. The Pond Manifesto

https://freshwaterhabitats.org.uk/wp-content/uploads/2016/06/EPCN-MANIFESTO.pdf

Hepburn, R. 2012. Proposed Northern Relief Road, Durham City, Ecological Assessment, Extended Phase 1 Survey. Durham County Council.

durhamcc-consult.limehouse.co.uk/file/2902108

Julian, A.J. & Hand, N.K. (2018). ARG UK Advice Note 11. Managing Habitat for Adders: Advice for Land Managers. Amphibian and Reptile Groups of the UK.

Lewis B., Griffiths R., Wilkinson J., and Arnell A. 2011. Examining the Fate of Local Great Crested Newt Populations Following Licensed Developments. DEFRA.

http://sciencesearch.defra.gov.uk/Default.aspx?Menu=Menu&Module=More&Location=None&Completed=0&ProjectID=17856

Chris Monk, Oct 2016. Land Management in the English uplands and the consequences for adders. Presentation at Vanishing Vipers Conference, Amphibian & Reptile Groups UK.

https://www.arguk.org/info-advice/scientific-and-technical-reports/presentations-from-vanishing-viper-october-2016/311-chris-monk-land-management-in-the-english-uplands-and-the-consequences-for-adders-pdf/file

North Pennines AONB Partnership, 2018. North Pennines Area of Outstanding Natural Beauty Management Plan 2019-24.

http://www.northpennines.org.uk/wp-content/uploads/sites/37/2018/12/North-Pennines-AONB-Management-Plan-2019-24-Consultation-Draft-1.pdf

Williams P., Biggs J., Crowe A., Murphy J., Nicolet P., Weatherby A., Dunbar M. January 2010. CS Technical Report No. 7/07. Ponds Report from 2007. Countryside Survey. https://freshwaterhabitats.org.uk/wp-content/uploads/2015/03/Countryside-Survey-Ponds-report-20071.pdf

Web sources:

Freshwater Habitats, Great crested newt conservation: district licensing pilot scheme

https://freshwaterhabitats.org.uk/projects/environment-bank/

North East England Nature Partnership (NEENP)

Biodiversity Priorities: - Lowland Heath; - Ponds, Lakes and Reservoirs

https://neenp.org.uk/natural-environment/durham-priority-habitats/lowland-heath-action-plan/

https://neenp.org.uk/natural-environment/durham-priority-habitats/ponds-lakes-and-reservoirs-action-plan/