Do any introduced Painted Frogs still survive in Manchester?

Discoglossus pictus from Sicily
Fabrizio Li Vigni here

In my last post I described how Louis Lantz had bred Painted Frogs (Discoglossus sp.) in Manchester. Because he was unable to rear the young to adulthood he released them into his garden. There grew and bred, and he described how he could then collect them for breeding experiments and to pass on.

The frogs left to fend for themselves in the garden spawned in small open air ponds and spread in neighbouring gardens and garden ponds. This introduction was noted in Deryk Frazer’s Reptiles and Amphibians in Britain (Collins, 1983) with the comment that it was not known whether there were still individuals surviving from Lantz’s releases.

No address was given for Lantz in the 1947 paper in which he discussed his keeping and breeding these frogs and so I suspect that anybody searching the Manchester area would have had no clue as to where to begin looking. The 2017 biographies of Lantz provide two addresses in  the Manchester area where he kept and bred amphibians and reptiles. With the help of genealogy search sites it is possible to pin down the approximate dates he was living at the two locations.

The paper published in 1947 was submitted in March 1946. Given the usual period taken to prepare a final draft we can estimate that Lantz wrote his part at the end of 1945 or in very early 1946. He wrote that he had made the observations ‘during the last 15 years’; in other words around 1930. The first breeding experiments he described were in 1932. At this time Lantz was living at 9 Waterpark Road, Manchester 7. I see from Google Earth that there is a lake in Broughton Park only 130 metres from Lantz’s house. He was still there with his family in 1935. Unfortunately at the time of the 1939 Register, a special census taken in preparation for war, he and his wife were guests at a hotel in Wales but by 1940 he had moved to 2 Kinnaird Road at Withington where the photograph I showed in the last post of his greenhouse was taken. It was at Kinnaird Road that Lantz collected spawn from a neighbour’s pond.

In recent years the single species of Painted Frog has been split into five or six. Lantz explained where he had obtained his frogs and it therefore possible to assign currently recognised species [in square brackets below] to the ones he collected, bought or was given:

Some of the material was collected by the author on Port-Cros and Levant Islands near Hyeres, where the species had not previously been recorded [D. sardus], and later also on Corsica [D. sardus but also possibly D. montalentii]. A few Sardinian [D. sardus] and Portuguese [D. galganoi] specimens were obtained from dealers, but many fine and valuable animals are due to the kindness of Mr J. Armitage (1 specimen from Corsica [D.sardus or D. montalentii]), Gen. M. Berquet (10 specimens from Tunisia [D. pictus]), Mr O. Cyren (3 specimens from Morocco [D. scovazzi]), and Mr R. Maxwell Savage (7 specimens from Port-Cros [D. sardus]), to whom sincerest thanks are expressed. 

In respect of Lantz’s breeding experiments between what were clearly D. sardus (then considered a subspecies, D. pictus sardus) from Sardinia and Port-Cros and D. pictus ( D. p. pictus) from Tunisia, it is interesting to note that these two ‘species’ interbred and back-crossed freely. As in his studies on newts he was interested in the inheritance of skin colour and pattern. What was then pictus came in two dorsal patterns: spotted and striped; sardus spotted only. He found inheritance was of the simple Mendelian type, with ‘striped’ dominant over ‘spotted’.

However, the purpose of this post was not to question whether the current species recognised are good ‘biological’ species, but to point out the existence in the 1930s and 1940s of breeding sites in the Manchester area of introduced Painted Frogs. Although the odds of their continued existence seem long, it is surprising how many gardens in England still have thriving colonies of introduced Midwife Toads. Lantz was not the only herpetologist to introduce deliberately or accidentally Painted Frogs in England. North London in 1960 was the second instance noted by Frazer. Painted Frogs were also commonly imported by dealers, particularly in the earlier decades of the 20th century and numbers must have been released into insecure ponds and vivaria over the years. There are also at present current breeders of one or more species of Discoglossus in Britain.

But back to the original question: has anybody in Manchester had a look or plans to look for Painted Frogs? 

Lantz's plate from the 1947 paper showing his breeding experiment
Original capton wording superimposed on each figure

Distribution of Painted Frogs (Discoglossus)

Bruce HM, Parkes, AS, Lantz LA. 1947. Observations on Discoglossus pictus Otth. Proceedings of the Royal Society B 134, 37-56 (plus two plates).