RAUK - Archived Forum - Posts by Peter Sutton:

I have just returned from a trip to the Somerset Levels where I caught up with the 'Green' frogs at Shapwick Heath NNR. I found them there in 2003 during an entomological survey. There is a large population in the two ponds immediately to the right of the entrance through the trees and bushes, and a correspondingly good population of grass snakes. They looked like Edible Frogs at first sight, with dorsal stripes etc, but the 'heel' of the hind leg easily extended beyond the tip of the nose, so I am assuming that they are all Marsh Frogs. (Also dark eardrum).

When were these populations first discovered? They are not in the BRC Atlas or the NBN Gateway maps.

Peter Sutton

As per my message on the 'naturalised species' area of the forum, I examined a large specimen of a Somerset 'Green Frog' and its heel clearly extended beyond the snout. General opinion states that these are not Marsh Frogs, and my initial id was that they looked like Edible or Pool Frogs. How reliable is the method of determining species using the length of the hind leg? If it is reliable, the Somerset Green Frogs appear to be Marsh Frogs, or at least, have Marsh Frogs among their number. (Photograph available)

Peter Sutton

I have noticed that Portland specimens of the Viviparous Lizard occasionally have a remarkable green hue, as do some Devon specimens, and put it down to the fact that they were all in close proximity to maritime habitats... a somewhat weak argument based on the fact that I had never seen this colouration in any inland colonies. The most extraordinary colour I have seen on L. vivipara was a full blue belly, although the specimen was recently deceased and this may have been due to some decomposition process. (I have a slide of this specimen)

Peter Sutton

I understand that there were two remaining sites, but one was lost, to pollution I think. The last remaining population is holding on, thanks to a breeding programme (Jersey Zoo) and constant surveillance, and I believe that the breeding programme is/has attempted to introduce specimens to both old and new sites that are suitable for recolonization.

Peter Sutton

I have found Typhlops vermicularis on Corfu to the south of Pantokrator and at Agios Gordis, both times under rocks used by ants. I presume they take the ants at all stages of their life cycle.

Peter Sutton

Thanks Chas, I have studied the Somerset Levels for some time now and accumulated a great deal of literature, but have not come across any reference to the Green Frog tribe. Bernard Storer wrote a Natural History of the Somerset Levels which is described as "one of the most important twentieth century books on English natural History" and does not mention Green Frogs. (That said, he claims that Natterjack Toads were present on Sedgemoor which I find highly dubious! .....could it be that someone had heard the Green Frogs' quacking call and misidentified it?!) I look forward to receiving any further details that you might find. Best regards

Peter

I have posted messages relating to Somerset Green Frogs on the 'Naturalised species' and 'What is it' areas of the forum, but if there is an answer to this question in the following exerpt, it may be of interest for indentification purposes:

" I examined a large specimen of a Somerset 'Green Frog' and its heel clearly extended beyond the snout. General opinion considers the Somerset Green Frogs to be Edible or Pool Frogs, and that was my original gut feeling when I saw them. How reliable is the method of determining the three species found in the UK using the length of the hind leg? If it is reliable, the Somerset Green Frogs appear to be Marsh Frogs, or at least, have Marsh Frogs among their number.

Any feedback very welcome! (Particularly literature references to the Somerset colonies and their i.d.)

Peter Sutton

Thanks Jon,

there are images but I need to work out how to reduce the resolution to get them on the site. I have looked again at the pictures, and the heel just clears the snout of the Somerset Green frog, which according to Beebee and Griffiths is a Marsh Frog. However, the diagrams in the Surrey Atlas by Wycherley and Anstis are different. The specimen still appears to conform to the Marsh Frog on account of the fact that it is stated that the heel of the Edible Frog doesn't pass the snout, but in these diagrams, the Marsh Frog's heel is regarded to be "well past the snout", perhaps a case for a note in a journal to discuss the confusion.

Will try to get the picture on the forum. Thanks again,

Peter Sutton

For interest, there are still remnants of a Natrix tesselata population at the Beam Brook ponds in Newdigate, i.e. what appear to be hybrids. For that matter, there are an array of variously marked snakes including those which have the characteristic dorsal stripes of Natrix natrix persa. The site is still as interesting as it ever was, and although the Wall Lizard, Fire Salamander, Marbled Newt and European Tree Frog colonies appear to have been lost (all but the Fire Salamander, which was regularly found for many years, were short-lived populations from accounts by the former proprietor of the site...and the tree frog population that resided in reeds at the front of the site has, as far as I am aware, not been recognised in any literature), the Alpine Newts, Italian Crested Newts, Pool and Edible Frogs are all still going strong. 

Peter Sutton

Hi Jon,

I am attempting to attach a picture of a Somerset Green Frog (From Shapwick Heath) which, by measurement, shows the heel just extending beyond the snout.

I am still confused by the differences between the green frog 'heel' diagrams in Beebee & Griffiths, and Wycherley & Anstis. Is the latter an accepted update, and does that make the former diagrams in B&G partially (i.e. with respect to ridibunda)

obselete?

Kind regards

Peter

Peter Sutton

In the alien species/Natrix tessellata topic area I posted a message regarding the strange phenotypic mix of the Natrix tribe to be found at Newdigate in Surrey, and stated that there appeared to be Natrix tessellata hybrids present at the site.

Having questioned this bold statement (because I consider the possibility of hybridisation between N. tessellata and othermembers of the genus somewhat unlikely) I again reviewed my pictures of specimens photographed at the Newdigate site, and I am still no closer to a conclusion!

I have not photographed specimens of the typical British species Natrix natrix helvetica at the site, almost certainly because of the prevalence of hybridisation with European types:

Typical N.n.helvetica Berkshire specimen

Many individuals are boldly marked and have dorsal stripes typical of Natrix natrix persa:

Some specimens appear to be hybrids of Natrix tessellata. It could be argued that they are typical of the olive grey form of Spanish Natrix natrix astreptophora but the positioning of the nostril, and the fact that there appear to be two preocular scales as opposed to the one of Natrix natrix sp. seems to preclude this. And yet...there are only seven upper labials...hence my assuption of a natrix/tessellata hybrid:

Having reviewed the case again, my own feeling is that it is not, and cannot be a hybrid, and that the apparent separation of the preocular scales may not be as complete as it looks.

Any thoughts will be very welcome!!!

Many thanks

Peter Sutton 

Here are a couple of close-ups of the pre-ocular scales of the olive grey Natrix sp.:

There appear to be two pre-ocular scales suggesting Natrix tessellata, this specimen had no yellow collar scales and a comparatively large triangular head.

Peter Sutton

Here are some more pictures of green frogs from the strong colony at Shapwick Heath NNR:

I have just seen Dave Bird's message in the 'naturalised species' section regarding the problems of trying to identify green frogs using morphometrics alone. It would appear that a good sound recording or DNA evidence is required to resolve this matter regarding the true identity and possibly the original source of the Somerset Green Frogs. 

Peter Sutton

Many thanks Jon, much appreciated.

Is there a standard or recommended kit for producing high quality sound recordings of these species? I would like to pursue this method of i.d. Who would I send the recordings to?

Peter

Hi Dave,

I have been visiting the Newdigate site virtually every year for over 20 years and I am currently writing a historical account of the reptiles and amphibians that have been recorded there.

In brief, the site (which was formerly partially accessible through the owner of the now closed aquatic nursery, but is now fenced off with a high tech. security system and requires specific permission from the owner of the (Bill Kear) Plant Hire company which occupies part of the site) is well known for its extant populations of Alpine Newt and Italian Crested Newts, Edible and Pool Frogs.

Formerley there were populations of species which have been documented in literature such as the Fire Salamander (per Wycherley and Anstis (Surrey herp atlas), and those that have not including Wall Lizards (sp. unknown), a colony of European Tree Frogs, Marbled Newts, and a couple of other species (all based on accounts from the owner of the aquatic nursery) which have not been documented.

The Natrix sp. present indicate, as above, a high degree of hybridisation with N.n.helvetica.

All three British newts are present, and hybridisation between T. cristatus and T. carnifex is perceived to be a significant problem, although the resulting hybrids are reported to have much reduced fecundity which limits their ability to establish a wider distribution.

There are still Red-eared Terrapins in the adjacent Brook, and I believe there were once E. orbicularis but have not been able to substantiate this. 

For me the Newdigate site has always been a special place, from the first time I turned up as a boy on an old rusty bicycle after reading about the presence of Alpine Newts in Christopher Lever's 'Naturalised Animals of the British Isles'. At present the ponds are still there but the owner of the site has little or no interest in maintaining them and they are beginning to get shaded with scrubby growth and trees. If I had the money I would buy the site for posterity! I will never tire of studying water life in those remarkable ponds, or watching water frogs sitting among the colourful blooms of old Victorian strains of water lily that still grow at the site to this day.

Kind regards

Peter Sutton

Hi Steve,

Gone I'm afraid. I have the exact location for where the Wall Lizards used to occur, but the colony was small and localized and has not been seen for many years. I have been visiting the site since the mid-eighties and I have never seen a Wall Lizard there. This is among a number of species whose existence at the site has been definite but transitory.

All best

Peter

Have there been any attempts to identify the origin of the current Norfolk population of Emys orbicularis?

I was interested to read that the species is present at more northerly latitudes in Poland, and is able to persist due to a combination of the longevity of the species, and the occasional hot summer that provides temperatures warm enough to allow for a successful hatch.

Could it be at all possible that this species has persisted at low density in East Anglia since its post glacial arrival in the UK? I find it very hard to believe....surely there would be recent evidence in the peat record?

(Although, thinking logically about it in terms of the vast expanse of peat formed, the amount that was actually expoited for fuel etc., and the low density of Emys populations...... searching for the remains of the odd carapace would probably be like looking for a needle in a haystack.)

Peter Sutton

Emys orbicularis, found at Tilgate Lakes, West Sussex 1986

I understand that there have been nothing more than sporadic sightings of Emys in Norfolk, but questions have been asked regarding the possibility of relict populations in northern Europe and the Norfolk Broads. I am still highly sceptical but in the light of the Rana lessonae discovery, would like to gauge current opinion.

Peter Sutton

Many thanks Steve,

Will do. I would be interested to know if there is a distinct cut-off point (observable in peat record or otherwise) viz post bronze-age disappearance of Emys in East Anglia.

All best

Peter