A survey of the Reptilia and Amphibia of Suffolk

A SURVEY OF THE REPTILIA AND AMPHIBIA OF

SUFFOLK

MARK JONES

H e r p e t o l o g y , t h e study of reptiles and amphibians was, until two or t h r e e d e c a d e s ago, an u n d e r s t u d i e d b r a n c h of natural history with only a very small following. This was partly due to the myths and fables which have surr o u n d e d s o m e of these c r e a t u r e s since medieval times (if not b e f o r e ) . T h e r e is still w i d e s p r e a d p r e j u d i c e against amphibians and reptiles.

O n e effect of this a b h o r r e n c e was that little interest was shown in t h e habits and biology of the British frogs, t o a d s , newts, lizards and snakes. T h e surge of interest in h e r p e t o l o g y has been since the last war, and particularly since t h e 1960s. N u m e r o u s b o o k s , p a p e r s and o t h e r publications h a v e , in recent years, b e e n p r o d u c e d to cover just a b o u t every aspect of t h e subject and these have b e e n c o m p l e m e n t e d by television d o c u m e n t a r i e s , films a n d radio p r o g r a m m e s . A s a result, t h e r e has d e v e l o p e d a great deal of concern over t h e n e e d t o p r o t e c t and conserve what remains of our h e r p e t o f a u n a , which is u n d e r increasing pressure f r o m the activities of M a n . D e s t r u c t i o n and d a m a g e t o h e a t h l a n d (a p r i m e habitat for s o m e species of reptiles), pollution, draining or infilling of f a r m p o n d s (essential b r e e d i n g sites for a m p h i b i a n s ) , h e d g e r o w r e m o v a l , u r b a n i s a t i o n , roadbuilding, d e v e l o p m e n t of coastal holiday resorts, loss of old m e a d o w s and w o o d l a n d and overtidying of c o u n t r y c h u r c h y a r d s a r e all pressures adversely affecting p o p u lations of a m p h i b i a n s and reptiles. Their n u m b e r s , not only in Suffolk, b u t over t h e entire c o u n t r y are decreasing at a gradually accelerating p a c e , and in s o m e species this h a s b e e n associated with a contraction of r a n g e .

T h e s e survey results include i n f o r m a t i o n and data g a t h e r e d f r o m a n u m b e r of sources, including R o p e (1934), the Suffolk Naturalists' Society T r a n s actions since t h a t t i m e , r e c o r d s g a t h e r e d by A . L e u t s c h e r and H . M e n d e l during the late 1970s, those g a t h e r e d by t h e a u t h o r over t h e last 20 years, and r e c o r d s sent in by m a n y c o r r e s p o n d e n t s , o f t e n in answer to appeals.

M u c h of t h e w o r k involved in r u n n i n g this survey was possible only because of t h e r e s o u r c e s and c o - o p e r a t i o n of t h e Suffolk Biological R e c o r d s C e n t r e ( S B R C ) , a n d highly productive fieldwork was u n d e r t a k e n during the a u t h o r ' s e m p l o y m e n t as a R e c o r d s Assistant at the S B R C f r o m N o v e m b e r 1983 to F e b r u a r y 1985. Distribution m a p s and detailed r e c o r d s relating t o t h e m a r e filed at t h e S B R C , Ipswich M u s e u m .

C o m p a r e d t o w a r m e r parts of t h e w o r l d , N o r t h e r n E u r o p e is relatively i m p o v e r i s h e d in t e r m s of n u m b e r s of species and p o p u l a t i o n s of reptiles and a m p h i b i a n s . T h e few species p r e s e n t are specifically a d a p t e d to survive in cold climates, although a few of t h e rarities in Britain (e.g. N a t t e r j a c k T o a d , Sand Lizard a n d S m o o t h S n a k e ) are on t h e n o r t h e r n limit of their E u r o p e a n ranges and can only survive in a few habitats w h e r e o p t i m u m conditions prevail. F u r t h e r south in m a i n l a n d E u r o p e they are o f t e n f o u n d and in a g r e a t e r diversity of habitats.

T h e r e a r e f o u r species of Reptiles indigenous to Suffolk: two s n a k e s , t h e A d d e r , Vipera berus, and t h e G r a s s - s n a k e , Natrix natrix helvetica (the

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Western E u r o p e a n subspecies, also known as the Barred Grass-snake); and two lizards, the C o m m o n or Viviparous Lizard, Lacerta vivipara, and the Slow-worm, Anguis fragilis, a legless and superficially snakelike form.

Five species of Amphibians are known to be indigenous to Suffolk. T h e tailed amphibians (Caudata) comprise two species of newts, the Great Crested Newt, Triturus cristatus, and the Smooth or Common Newt, Triturus vulgaris. T h e tail-less amphibians (Salienta) are represented by three species: the C o m m o n Frog, Rana temporaria, the Common T o a d , Bufo bufo, and the Natterjack Toad, Bufo calamita, now believed to be extinct in the County.

This account does not cover the occurrence of marine species of reptiles, the turtles, which are occasionally washed ashore or caught off the coast.

Long extinct species such as the European Pond Tortoise, Emys orbicularis, known to have occurred in Suffolk during the warm interglacial periods, are also ignored.

Tailed Amphibia (Urodela or Caudata) Smooth or Common Newt (Triturus vulgaris) [Map 1] This species is widespread over most of lowland Britain, and is the only species of newt found in Ireland. It is still reasonably abundant in Suffolk and has been recorded throughout most of the County, occurring on both heavy and light soils. It is the most widespread of the County's amphibians and

Map 1

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often persists in areas f r o m which the other species have disappeared. This may be due to its adaptability with regard to breeding sites; it will happily use small bodies of water and will readily colonise recently-formed pools. The Smooth Newt is widely recorded f r o m suburban garden ponds and, unlike the C o m m o n Frog, seems to be able to compete and co-exist with fish such as R u d d , C a r p and Goldfish where they occur in low or medium population densities in such ponds.

I have encountered Smooth Newts in a wide range of breeding sites; roadside ponds and ditches in the arable 'prairies', slacks on coastal sand dunes, Forestry Commission reservoirs and even artificial garden ponds with a capacity as little as 25 gallons. Indeed, garden populations in towns such as Beccles and Ipswich often reach high densities. On several occasions I have removed dozens of adults when cleaning out comparatively small ponds. The Smooth Newt is truly an adaptable species and a prolific one which can build up its n u m b e r s in a very short time.

Smooth Newts are most easily found during the breeding season when they gather at breeding sites. In East Anglia they generally start to enter the water from between the end of February and mid-March, depending on temperature, and can readily be found by netting ponds or by 'torching' (shining torches into the water) at night, when they tend to come to the surface and edges of their breeding pools. Newts can also be detected by the presence of eggs and larvae, although a trained eye is necessary for this.

During their terrestrial phase, which takes up the greater part of the year, newts can be found in fairly close proximity to their breeding sites. They are nocturnal at this time and will shelter in d a m p concealed places during the day. Piles of rubble, logs, dense vegetation and cracks and holes in the soil are favourite hiding places, and in areas of high populations many individuals may congregate in suitable shelters.

Great Crested or Warty Newt (Triturus cristatus) [Map 2] This is the largest of the three British species, and is widespread in Suffolk.

However, it is far less common than the Smooth Newt and appears to be more specific and less adaptable with regard to breeding sites. It occurs, in nearly all cases, on the heavy clay areas and generally prefers larger, deeper ponds. Marlpits, field ponds and moats are likely sites for G r e a t Crested Newts and I have often found them in large old ponds on uncultivated commons, in both Suffolk and Norfolk.

Generally speaking, where the Crested Newt is present, the Smooth Newt will also be f o u n d , although not vice versa. W h e r e the two species occur together, the Great Crested Newts will tend to inhabit the deeper parts of the pond and will forage on the bottom, whereas the Smooth Newts will tend to be found in shallower water and will often swim and feed just under the surface. T h e breeding seasons of both species are of similar duration, although the Great Crested Newt seems to stay closer to its ponds when out of the water. Although the Great Crested Newt has been recorded f r o m a few artifical garden ponds (e.g. at Campsea Ashe and Mendlesham) it seems to be a reluctant coloniser. However it often occurs in large natural ponds in gardens. I have only found this species on one heathland pond in Suffolk, at

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W e n h a s t o n Blackheath, and this was immediately adjacent to an area of heavier clay soil.

T h e G r e a t Crested Newt grows to a maximum length of a r o u n d 6V2 inches as opposed to AV2 inches for the Smooth Newt. Adults of the two species can be distinguished from each other by this size differential.

Palmate Newt (Triturus helveticus) This is the smallest of the British newts and, although widespread in parts of Britain, appears to be absent f r o m most of East Anglia and the East Midlands.

T h e r e are several theories for this distribution, one being that the Palmate Newt prefers soft water areas, whereas the other two species favour hard water areas. There is also some evidence that it is more tolerant of acidic pools (e.g. on heath and moorland). The Palmate Newt is the commonest and often the only species present in mountainous areas of Scotland, Wales, N o r t h e r n England and the extreme Southwest, and is also widespread on the North Downs and in parts of the New Forest. In some parts of Britain it can be f o u n d in company with Crested and Smooth Newts.

Epping Forest is probably the nearest the natural range of the Palmate Newt approaches to Suffolk. I have never recorded it from Suffolk, or f r o m N o r f o l k , with the exception of an introduced colony in Ipswich. Individuals were collected f r o m Berkshire c.1957 and introduced into a garden pond behind a house on T u d d e n h a m R o a d . They still occurred there with a larger colony of C o m m o n Newts in 1984, when I visited the site.

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Tail-Less Amphibia (Anura or Salientia) Common Frog (Rana temporaria) [Map 3] This species is widely distributed in the British Isles and is the only m e m b e r of the true frogs (Genus Rana) native to this country.

Formerly the C o m m o n Frog was almost certainly abundant throughout Suffolk but, although still widespread it appears to be localised or absent from the more intensively-farmed areas. Populations that do occur are often small and therefore vulnerable. Some rural areas still support large populations, notably parts of the coastal heaths and marshes and some of the less intensively-farmed river valleys where pastureland is still predominant.

Uncultivated village greens and commons with ponds are also likely to have strong resident colonies of C o m m o n Frogs.

This species has been extremely successful in colonizing urban gardens and most towns have considerable populations. Many of the records received from urban areas refer to garden ponds. T h e C o m m o n Frog is often found in company with the Smooth Newt in these circumstances, and both species can build u p dense populations in a relatively small territory.

In Suffolk, the C o m m o n Frog's breeding season begins in early March and has a duration of two or three weeks. Some individuals, notably adult males, tend to hibernate in the water, although not necessarily in the same pond they will use for breeding. Females generally overwinter on land and travel to their breeding sites in early Spring and, at this time, colonies are easily located as the males can be heard croaking. Shortly after pairing, the spawn is

Map 3

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laid in shallow water where it is often easily seen. Later in the year the tadpoles can be found in their various stages of development until they m e t a m o r p h o s e , generally in late summer.

Occasionally adult frogs are found dead on roads killed by traffic whilst attempting to travel to or f r o m breeding ponds. However, they are much less likely to be killed in this way than C o m m o n Toads, possibly because they do not disperse as far f r o m their breeding ponds.

O n e of the problems in accurately recording populations of C o m m o n Frogs is that, every year, large-scale human-assisted movement of spawn takes place. I know of several instances where frog-spawn has been collected f r o m as far away as Scotland and 'imported' into garden ponds in Suffolk. It is sometimes impossible to determine whether a garden population is truly indigenous. T h e r e are also large scale movements of spawn between donor and recipient ponds throughout the County which must greatly assist genetic variety within populations.

Common Toad (Bufo bufo) [Map 4] Widespread throughout England, Scotland and Wales, including some offshore islands, the C o m m o n T o a d , like the Frog, must have been abundant in every part of the County in the recent past. Although it is still recorded f r o m most areas, remaining populations in the heavily-farmed arable tracts seem to be declining. Large populations are particularly prevalent in less intensively-farmed terrain, in particular along much of the coastal strip and in Breckland. Populations in other parts of the County tend to be more

Map 1

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sporadic with evidence of small relict populations in some heavily-farmed areas.

The C o m m o n Toad appears to be less adaptable to breeding in artificial garden ponds than the Frog, avoiding small ponds. The incidence of Toads using urban garden ponds is much lower than for either the Frog or the Smooth N e w t , although there are exceptions. For example, many garden ponds in Southwold seem to be used by Toads, but this may be due to the huge n u m b e r s living on the marsh and common land adjacent to the town. In Ipswich, Lowestoft and Beccles Toads appear to be much scarcer in gardens than Frogs. In Halesworth, the large numbers of Toads which used the canal as a breeding site until the late 1960s/early 1970s seems to have virtually disappeared and Toads are hardly ever found in or around the town.

However, the Frogs which used the same site and declined at about the same time and had several 'lean' years have, since the turn of the decade, appeared in ever increasing numbers on the new housing estates, where they breed in ponds intended for goldfish.

Toads do seem to favour larger and deeper bodies of water and will often breed on the margins of lakes and meres and in large old ponds on village greens and commons. They are more loyal to a particular breeding site than Frogs. T h e presence of toadspawn is less obvious than frogspawn as it is laid in long strings and wound around submerged water plants. Hybridisation between T o a d s and Frogs is biologically unlikely although I have occasionally seen 'mixed' pairings.

C o m m o n Toads are known to return year after year to certain favoured breeding sites. It has been suggested that adult Toads may wander up to 2Vi miles f r o m their breeding pool. They appear to possess a homing instinct, the working of which is still not fully understood, and often face a hazardous journey. It is reckoned that many thousands are killed or maimed by motor vehicles each Spring, and such carnage must have a significant effect, particularly on populations already in decline.

The Natterjack Toad (Bufo calamita) [Map 5] On the northern fringe of its range the Natterjack has a wide but very localised distribution in the British Isles. Its stronghold is now the coastal dune systems of Lancashire, Cumbria and the Solway Firth. It is extinct f r o m similar areas of North Wales and Cheshire and the large colonies once found in Surrey, Kent and even South London have all but gone, except for a small population on the Surrey/Hampshire border. It is now also extinct in Dorset.

East Anglia was once a stronghold for the Natterjack with populations in the Gaminglay/Sandy area of Cambs/Bedfordshire and coastal stations in Norfolk and Suffolk as well as on several inland heaths.

T h r o u g h o u t its British range, the Natterjack is associated with heathland or coastal dune systems and is highly specific regarding its requirements. T h e fact that many of these habitats have been destroyed or altered helps to explain the dramatic decline of this species in both range and population since the turn of the century. It has disappeared from all the sites in the County referred to by R o p e (1934) although it seems to have persisted near Southwold until after the last war. Harold Jenner recorded the Natterjack

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f r o m Fritton Warren until c. 1961 (pers. comm.). T h e afforestation of this site with conifers in the late 1940s appears to have led to the Natterjack's extinction in the area. Similarly in Norfolk, most of the known populations had disappeared by the 1960s. T h r e e sites remain, and are all now partly or wholly managed as nature reserves.

In view of the habitat requirements and distribution of the Natterjack in Suffolk the inland record mentioned by R o p e at Tostock seems unlikely.

Oddly perhaps, it has never been reliably recorded from Breckland, either in Suffolk or Norfolk. It is likely that the Natterjack was far more widely distributed in Britain when the climate was warmer, and that the present eccentric and contracting distribution is at least partially a result of climatic change. Elsewhere in E u r o p e the Natterjack becomes more c o m m o n to the South and West, and is particularly widespread and abundant on the Iberian Peninsula and in southern France. In the Low Countries, North Germany and n o r t h e r n Poland it tends to favour similar habitats to those occupied in Britain.

Reptilia Common or Viviparous Lizard (Lacerta vivipara) [Map 6] This small lizard has one of the most extensive ranges of any reptile in the world, encompassing most of north and central E u r o p e and a wide belt across central Asia to the Pacific coast at Sakhalin. It is widespread in the British Isles and is the only reptile found in Ireland.

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In Suffolk, C o m m o n Lizards generally seem to favour the lighter soils and appear to be most abundant in sandy areas. They are widespread on the Sandlings, including suitable adjacent habitats, and also in Breckland.

Elsewhere, the C o m m o n Lizard occurs in churchyards, on railway embankments and cuttings, on unimproved grasslands, along hedgerows, in woodland rides and clearings, on coastal dune systems and along coastal cliffs. In other parts of Britain it is found in mountain and moorland areas.

I have found Lizards to be common on various sites along the Waveney Valley, o f t e n existing in apparently isolated populations. W o r t h a m Ling, Outney C o m m o n (near Bungay), Barsham churchyard and Beccles Common all have populations. A colony also survives in South Lowestoft, at Kirkley H a m , an area now completely surrounded by urban development.

Until a few years ago there was a colony on relict heathland at the site of the old Lowestoft golf course off Black Heath R o a d , but this has now been built over. Sandling populations are still extensive and even the smallest patches of heathland will often support a population. Records from the centre of the County are less f r e q u e n t and this generally coincides with the most extensive tracts of clay-based soils.

Slow-worm (Anguis fragilis) [Map 7] This legless species of lizard tends to be more localised and less common as one moves North and East in Britain, and its distribution in Suffolk is decidedly patchy. It is recorded from the Sandlings and adjacent areas but

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Map 7 seems to be scarce in Breckland. However, unlike the C o m m o n Lizard, it is as likely to be encountered on clay soils as on sandy ones and so is perhaps more evenly distributed in the County than the C o m m o n Lizard.

Many of the records refer to specimens found in country churchyards, and these areas of relict grassland seem to be favoured. In many cases the Slow-worm and the C o m m o n Lizard share the same habitat, notably on heathland and railway embankments/cuttings, and can be found in close proximity. Slow-worms occasionally turn up in large unkempt urban gardens and on wasteland. I have never found the species on coastal sand dunes and only once, some 20 years ago at Halesworth, on wet pastureland, and this was fairly close to a railway e m b a n k m e n t , a more usual habitat.

Some suitable localities seem to encourage high population densities.

Large n u m b e r s were removed a few years ago and re-located f r o m a few acres of rough scrubland in an old orchard off Rigbourne Hill in Beccles, prior to the site being built on. I found well over a dozen on one visit alone, and there is little doubt that there were many more.

Adder or Viper (Vipera berus) [Map 8] T h e only poisonous British reptile, the A d d e r has a very wide E u r o p e a n and central Asian distribution. It is widespread in the British Isles but not found in Ireland.

In both Suffolk and Norfolk, it seems to be almost exclusively associated with light, sandy soils. T h e prime habitats are heathland or coastal dune systems, or areas adjacent to these. As the distribution map shows, the

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A d d e r ' s main strongholds are the Breckland heaths and woodland rides, in the north-west of the county, and the Sandling heaths from Lothingland south to the region around Hollesley. A d d e r s were almost certainly previously more widely distributed within these areas, but declined as the heathland became fragmented. T h e apparently isolated populations in the Redgrave/Lopham and Hinderclay Fen complexes may be remnants of more extensive colonies along the Little Ouse/Waveney Valley. My own observations lead me to believe that, unlike the C o m m o n Lizard and the Slowworm, this species tends to disappear from small, isolated heaths and also f r o m those subject to heavy recreational use or urban encroachment. T h e A d d e r is very shy of h u m a n interference and also probably needs a wide area to provide a d e q u a t e food. I have been reliably informed that A d d e r s were present on W e n h a s t o n Blackheath up until the 1960s, but after repeated and exhaustive searches over this 48 acre heath I am certain it is no longer present. It was present at nearby Blythburgh H e a t h (on the western side of the A12 trunk road) until 1972, when most of the heath was reclaimed for agricultural use. In the autumn of that year I removed four specimens, including a melanistic female, from a remnant of the heath next to the Wenhaston/Blythburgh road before that tract was ploughed up the following year.

A d d e r s will often persist in heathland given over to coniferous plantations living in the wide rides, and clear-felled blocks until the latter become too over-shadowed. These populations probably move in rotation with the felling and replanting regime.

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Grass-snake (Natrix natrix helvetica) [Map 9] T h e British range of this species is less extensive than that of the A d d e r ; it is absent f r o m Scotland and the extreme north of England, as well as Ireland.

In Suffolk it appears to be less localised than the Adder and it is often encountered on the heavier clay soils. However, it is not normally found in colonies and is more likely to occur in less dense, more widely-ranging populations. Oddly, the Grass-snake seems to be absent or, at least extremely u n c o m m o n on the Sandling heaths, although it is found on the Brecks. Grass-snakes are fond of watery, marshy places and their preferred diet consists of amphibians, especially Common Frogs. In Suffolk they favour river valleys but may be found in pastureland and woodland in arable areas.

T h e Grass-snake is well recorded f r o m the Waveney Valley and occurs on Bungay ( O u t n e y ) C o m m o n , Beccles Marshes and in the Herringfleet area.

In the south of the County many of the sightings relate to the Stour Valley and adjacent localities. This is an active, wide-ranging species and it can sometimes be seen crossing roads where it may be killed by traffic. Grasssnakes occur in deciduous woodland on heavier soils, where they can be found in rides and clearings. Bradfield Woods and Bentley W o o d s are examples of areas which support populations of this type.

T h e Grass-snake probably used to be more widespread and c o m m o n , but large areas of intensively-farmed arable prairies have little to offer it, and it has tended to decline along with its amphibian prey.

Unlike the A d d e r , this species is not viviparous; it is an egg-layer and

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requires incubation sites with some kind of additional heat source. For this reason females tend to seek out compost heaps, manure piles and sawdust heaps in which to deposit their eggs. As the countryside is 'tidied up', these vital hatcheries are disappearing and the loss of breeding sites is probably a m a j o r factor in the decline and local extinction of this snake.

Grass-snakes are strong swimmers and several records relate to specimens seen swimming across ponds, lakes, or even rivers.

Introduced Species From time to time reptiles and amphibians from the E u r o p e a n mainland or much f u r t h e r afield have escaped f r o m captivity or been deliberately released into the wild in the British Isles. In most cases such introductions do not survive for long; for most tropical or sub-tropical species the climate is too cold and they soon die. However, many European and some North American forms are able to survive for quite long periods although, with a few notable exceptions, they are generally unsuccessful in breeding due to our comparatively low summer temperatures.

In the past, before the recent import restrictions on the pet trade, some of the following species were fairly regularly encountered as 'escapes'.

AMPHIBIA REPTILIA

E u r o p e a n Green Tree-frog ( H y l a arborea varieties) Edible Frog (Rana esculenta varieties) Mediterranean Tortoise species (Testudo hermanni, Testudo graeca, etc.)

Red-eared Terrapin (Pseudoemys scripta elegans) E u r o p e a n Pond Tortoise ( E m y s orbicularis) G r e e n Lizard (Lacerta viridis) Wall and Ruin Lizards (Podarcis spp. & varieties) E u r o p e a n Grass-snakes (Natrix natrix varieties) Dice-snake (Natrix tesselata) Garter-snakes (Thamnopis sirtalis varieties)

The above is not an exhaustive list, but those species were formerly imported in very large numbers. A specimen of the E u r o p e a n Pond Tortoise was f o u n d in the river at Yoxford in summer 1984. This species is particularly hardy and was indigenous to these isles during inter-glacial periods. It can still survive here in the wild for years although its present natural distribution reaches its northern limit in central France.

In some cases introductions have been locally successful; the colony of Marsh Frog, Rana ridibunda, a Central E u r o p e a n species, developed from individuals which escaped f r o m a garden pond into Romney Marsh in Kent in 1935. They have since spread over the whole marsh complex and into adjacent parts of Sussex, finding the extensive dyke systems and pasturelands much to their liking. Similarly there is a colony of Pool-frogs, Rana lessonae, at a site in the Norfolk Brecklands near Thetford. Their origin is not known but they are believed to have been there for at least 150 years.

In the vast majority of cases introductions and escapes are irrelevant to our

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native h e r p e t o f a u n a although their occurrence can cause a great deal of confusion amongst naturalists!

Conservation and Protection T h e recent surge of interest in amphibians and reptiles has raised concern over their status. T h e rarest and most restricted British species, the Natterjack T o a d , Sand Lizard and Smooth Snake have declined the most drastically, due mainly to habitat alteration and destruction. T o a lesser degree the same thing is happening to the other species which have been traditionally m o r e a b u n d a n t and widespread. Our herpetofauna is dependent on comparatively stable and unchanging types of ecosystems, and these are becoming scarce in a country dominated by intensive agriculture and encroaching urbanisation and road systems.

For some amphibians adaptability to suburban conditions, aided by the popularity of the artificial garden pond, have provided an alternative habitat.

These species may still be losing ground in the open countryside (particularly in the predominantly arable lowlands such as Suffolk) but they are rapidly increasing in towns and cities.

Reptiles have been less successful in adapting to urban conditions, although both species of lizard found in the County are widespread on railway cuttings and e m b a n k m e n t s and sometimes occur well into suburbs in these artificial habitats. Generally speaking, the only way to conserve viable populations of the reptiles and the rarer, more specialised species of amphibians, such as the G r e a t Crested Newt and Natterjack Toad, is to preserve and maintain the habitats upon which they depend for survival.

Much research work has been carried out on the Natterjack T o a d since the early 1970s, notably by D r . Trevor Beebee. This has resulted in successful m a n a g e m e n t of existing sites and has also paved the way for introductions to sites f r o m which it has become extinct, and to new sites which have been m a d e suitable.

In 1985, following successful introductions of the Natterjack to sites in Bedfordshire and north-west Norfolk, a site on the Sandlings was chosen f r o m a short-list of possible Suffolk sites, for re-introduction of the species to the County. Approximately 900 well-grown tadpoles, raised f r o m a captivebreeding colony kept by the author were released on the site, which is regularly monitored by arrangement with the Conservation Committee of the British Herpetological Society, the Royal Society for the Protection of Birds (on whose land the site is) and the Nature Conservancy Council.

A t the time of writing (April 1988) well-grown Natterjacks are regularlyseen at the site and, during the previous winter, two large concrete 'slacks' or scrapes were constructed to supplement the naturally occurring, rather unpredictable pools a r o u n d the locality. In the coming years, if this introduction proves successful, it is to be hoped that further projects of this sort will be carried out in the County to re-establish the species.

T h e f u t u r e of the reptiles and the G r e a t Crested Newt in Suffolk seem to be particularly uncertain. A r e a s where these creatures still occur are gradually being reduced in area and changed; witness the destruction of heathlands

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Nat. Soc. 24

A SURVEY OF T H E REPTILIA A N D AMPHIBIA OF SUFFOLK

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around Ipswich, once undoubtedly rich in Adders, C o m m o n Lizards and Slow-worms.

Individual persecution of snakes and the snake-like Slow-worm still occurs, although perhaps not to the degree that it undoubtedly did thirty or forty years ago. It is just as well that 'snake-bashing' is less prevalent nowadays as all the species concerned are scarcer and their habitats far more fragmented and restricted. Unfortunately the very presence of large numbers of h u m a n s seems to be enough to cause the A d d e r to decline on the more heavily-used heaths. The large numbers of domestic and feral cats almost certainly have a marked effect on reptile populations close to towns and villages. Most cats will catch lizards and slow-worms and many will kill snakes. This additional predation may be the final pressure on creatures which already have to contend with natural predators, heath-fires, etc, and may lead to the decline and eventual extinction of some populations. In view of the increasing human population and all the problems this will bring, it is difficult to be optimistic about what changes the next two or three decades will bring.

Bibliography Appelby, L. G . (1971). British Snakes. John Baker.

Arnold, E . N. & Burton, J. A . (1978). A Field Guide to the Reptiles and Amphibians of Britain and Europe. Collins.

Beebee, T. (1985). Frogs and Toads. Whittet Books.

Beebee, T. (1983). The Natterjack Toad. Oxford University Press.

Ellis, E. A . British Amphibians and Reptiles. Norwich: Jarrold.

Frazer, D . (1983). Reptiles aftd Amphibians in Britain. Collins.

Simms, C. (1970). Lives of British Lizards. Goose & Son. Smith, M. (1973). The British Amphibians and Reptiles. Collins.

Steward, J. W. (1971). The Snakes of Europe. Fairleigh Dickinson University Press.

Steward, J. W. (1969). The Tailed Amphibians of Europe. David & Charles.

Street, D . (1979). Reptiles of Northern and Central Europe. Batsford.

Reference R o p e , E. J. (1934). The Reptilia of Suffolk. Trans. Suffolk Nat. Soc. 2, 209.

Acknowledgements Due to the massive response to the survey appeals made during the last ten years it is impossible to thank every contributor individually. I would like to thank all who helped me in this way, but especially Alfred Leutscher, Howard Mendel, John Digby, Marya Parker, Owen Douglas, members of the staff of the S B R C , John A n t r a m , John M u d d e m a n , Denys Lawrence,

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Suffolk

Natural History, Vol. 24

R . B. W a r r e n , John Minihane, Stuart West, Steven Burrows, T o m Langton, John B u r t o n , John Shackles, Harold Jenner and Jeremy Graves.

I also thank the S B R C for producing the distribution maps.

Mark Jones, 2 White H o u s e Farm Cottages, Spexhall, Halesworth, Suffolk.

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Nat. Soc. 24

Plate I : Natterjack T o a d . Bufo calamita — now extinct in Suffolk but recently re-introduced (pp 15 &. 22).

(Photo: H o w a r d Mendel)

Plate 2 : C o m m o n Lizard. Lacerta vivipara — widespread in Suffolk and most abundant in sandy areas (p 16).

(Photo: H o w a r d Mendel)