Monday 25 January 2021

Pallas’s Squirrel in Hong Kong: Feral pets, an introduced or reintroduced species…or even a range expansion?

Fifty years ago the sight of a wild squirrel in Hong Kong would have been unthinkable. But now, Pallas’s Squirrel (Callosciurus erythraeus) can be seen both on Hong Kong Island and in the New Territories. I have no reason to doubt the story that these populations were from the accidental or intentional release of squirrels imported for the pet trade. Well…perhaps a nagging doubt.

Pallas's Squirrel photographed in the New Territories of
Hong Kong by AJP, December 2020. Note the black
'spot' near the end of the tail. In the second photograph
the red belly can be glimpsed.

In the 1960s these squirrels, along with Siberian Chipmunks, were being sold as pets in Hong Kong. The ‘lab boys’ had a couple in a tiny cage in their room in the Zoology Department of the University of Hong Kong, for example. In view of the appearance of flocks of feral Yellow-crested Cockatoos we perhaps should not have been too surprised to have seen squirrels in the trees of Government House on our first return to Hong Kong in 1997.

The standard account of these squirrels in Hong Kong is that the ones on Hong Kong Island are different from those in the New Territories. Those on the island are described as belonging to the subspecies C.e. thai, with those in the New Territories as C.e. styani, the former from Thailand; the latter from Northern China. I am not sure how the feral animals in Hong Kong were assigned to these subspecies and having looked up some of the original papers I am even less sure about the identification of thai other than Thailand is perhaps where the animal dealers said they were imported from. The black hairs near the tip of the tail of the ones from the New Territories do, however, fit the description of styani. The import of the Siberian Chipmunk, Eutamias sibiricus, is also compatible with the importation of C.e. styani, into Hong Kong from the same area of northern China.

In many parts of its range the belly of the squirrel, as its specific name implies, is some shade of red. That is true of those in the New Territories of Hong Kong. That was not the case in at least some of those kept as pets. The ones the lab boys kept were a light yellowish grey—as were those we saw in the gardens of Government House 30 years later.

It does seem odd that a native squirrel had never been reported for Hong Kong. The question is if they were once there and had been extirpated or had never even been part of the native fauna. Two squirrels apparently from near Canton (now Guangzhou)—only 135 km (85 miles) from Hong Kong—were collected by John Reeves between 1812 and 1831; the skins are in the Natural History Museum in London. They are currently assigned to a subspecies, C.e. castaneoventris, with a distribution south of the Pearl River including the island of Hainan. Nothing seems to be known in formal descriptive terms of the Pallas’s Squirrels that occur over much of China (including the mainland north of the Pearl River adjacent to Hong Kong) and this leads me to the first of my nagging questions: is it just possible that the squirrels in the New Territories of Hong Kong are not feral but are native squirrels that have come over the border as Hong Kong became reforested after the devastation of the hillsides for firewood during and shortly after the Japanese occupation?

The whole taxonomy of squirrels of the genus Callosciurus seems to this outsider as a mess, in part due simply to a lack of series of specimens from most parts of the range. Clarity has not be advanced by simplistic molecular phylogenetic studies (using only mitochondrial DNA). That leaves me with a second nagging question: why, if two apparent subspecies were imported for the pet trade in the 1960s has one become feral in mainland Hong Kong and the other on Hong Kong Island? Surely, both would have been sold in the pet shops and bird markets on both sides of the harbour. Did they interbreed on the mainline side and if so does that mean that the ‘styani’ coloration is dominant to the ‘thai’?

Tackling the questions on the origins of the Pallas’s Squirrels would also help settle the obvious corollary: can those in Hong Kong be classified as an ‘introduction’ or a ‘re-introduction’ or even a natural range expansion?

Lurz PWW, Hayssen V, Geissler K, Bertolino S. 2013. Callosciurus erythraeus (Rodentia: Sciuridae). Mammalian Species 45, 60-74.

Moore JC, Tate GHH. 1965. A study of the diurnal squirrels, Sciurinae, of the Indian and Indochinese subregions. Fieldiana 48. Chicago: Chicago Natural History Museum.

Tuesday 12 January 2021

A Hong Kong Moth

 AJP found this moth in Hong Kong last week. It seems to be a female Eudocima homaena, noted as being a pest on orange trees in parts of its range.

Monday 11 January 2021

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).


Friday 8 January 2021

Louis Lantz: Frenchman, Manchester resident, outstanding herpetologist, and important in wider biological circles in 20th century Britain

My first memory of seeing the name Louis Lantz is of being mystified by the appearance in Malcolm Smith’s book, The British Amphibians and Reptiles I had taken out from the local library, of a graph showing growth curves after metamorphosis for three hybrid newts. That graph accompanied the text: ‘Mr L.A. Lantz’s observations on growth shew that the rate depends largely on the quantity of food available and on the length of period during which, because of low temperature or low humidity, little or no food is taken’. I remember being intrigued—who was this Mr Lantz and why did he have hybrids between two species, Triturus cristatus and Triturus marmoratus?*

Only many years later did I begin to learn who Lantz was, why he worked in Manchester, and of his various contributions to herpetology. Biographies published in 2017 in French and In English have attempted to make Lantz and his classical herpetology better known in his native France and in Russia where he had worked. Unfortunately his biographers have largely omitted or underestimated his rôle in the British scientific scene and in the development of genetics and cytogenetics by some of the big players in this then burgeoning field.

Lantz has been described as an amateur herpetologist. That he was in the sense that he was not paid for working on amphibians and reptiles. But he was a professional scientist and technologist who worked in herpetology in his spare time. Lantz was a scientist whether involved in his profession or his ‘professional’ hobby which is why he found collaboration with the major figures in genetics a normal part of scientific discourse. He is also described as having ‘kept salamanders as pets’. I think those of us who have or still do keep reptiles and amphibians would object strongly to use of the word ‘pet’ in such a context.

Louis Amédée Lantz was born in 1886 in Mulhouse, Alsace, now part of northern France but then annexed to Germany. After studying zoology and botany at the University of Montpelier in 1903-4 he moved to the school of industrial chemistry in Mulhouse. There be obtained a diploma in chemical engineering. The school specialised in teaching the use of dyes for the important local textile industry which concentrated on printed fabrics. The school attracted a number of Russian students and Lantz found a job in Russia in 1907. From 1908 he specialised in cotton dyeing and printing at a vast factory in Moscow. Forced to leave in 1918 because of the Russian Revolution—and having married a Russian—he held various jobs in France. Then in 1923 he was appointed Director of Research at the Calico Printers’ Association in Manchester. He stayed there until his retirement in 1951 at the retirement age of 65. Partly, he recorded, because of his wife’s health, he returned to France, intending to live in Paris in order to work at the natural history museum. He died in Lucern, Switzerland in February 1953.

From Ineich et al 2017


The laboratory in Manchester, was, for its time, a big one. It employed 20 graduates and 40 technicians seeking to improve and to develop new techniques for printing and dyeing. At the time of formation of the company by merger, Calico Printers was producing 80% of Britain’s output of printed cloth. As well as printing and dyeing, Lantz was also responsible for the development of new, synthetic fibres and coatings. Terylene or PET, later manufactured by ICI, was one outcome in 1941. He and his team had numerous patents for processes and materials they invented.

Having started to keep reptiles and amphibians at home in Alsace, Lantz took every opportunity to study reptiles in the wild, in the Caucasus while he was working in Russia, for example, and to undertake breeding experiments that directly addressed questions in systematics and taxonomy of the time. For example, were some European lizards simply geographical variants (subspecies) or true species? He thus became interested in the whole question of species definition and of genetic reproductive barriers between them. That is why he tried to breed hybrids in captivity and then see if their offspring were fertile.

He came under the influence of the German herpetologist Wilhelm Georg Wolterstorff (1864–1943), a major player in promoting amateur herpetology through the keeping of live animals and in linking amateurs with professional museum scientists, particularly in German-speaking countries. Wolterstorff was particularly interested in newts and salamanders and realised the value of hybridisation experiments. In 1903 he reported that a long-recognised species of newt, Triturus blasii, from western France was in fact a naturally-occurring hybrid between male Great Crested or Warty Newt, Triturus cristatus, and female Marbled Newt, T. marmoratus. Lantz took up the challenge of breeding such hybrids in order to investigate what was going on in terms of genetics in the zone where the northern T. cristatus and the southern T. marmoratus overlap and in which hybridisation sometimes occurs.

I will not describe further Lantz’s work on the lizards of the Caucasus, much of it done in collaboration with the Swede and fellow chemical engineer, Otto Cyrén (1878-1946) and which continued after he left Moscow in 1918. That and other aspects of his work, including keeping and breeding the Common Chameleon (Chamaeleo chamaeleon), have been extensively covered in the 2017 biographies. I shall instead, add to that information by indicating his involvement with the highest levels of research in genetics and cytogenetics in Britain.

A clue to the importance placed on Lantz’s work with newts can be found in the following quotation:

A few people have the capacity for noticing the exceptional very highly developed. I think particularly of my late friend L. A. Lantz, who was secretary of the British Colour Council. This is not, as might be thought, concerned with the rights of immigrants from tropical countries but with textile dyes; and its secretary doubtless had a fine eye for colour differences. He also had a fine eye for lizards and newts. His most remark­ able achievement in this respect was perhaps noticing that he could not tell the sex of a lizard which he saw running about, catching and killing it, and finding that it was an intersex. 

This is from an essay, On Expecting the Unexpected, published in the Rationalist Annual in 1960 and included in the collection, Science and Life, published as a book in 1968. It was written by J.B.S. Haldane. As I said, the top level of evolutionary genetics at the time. But Haldane (and his second wife, Helen Spurway (Haldan [sic] in the 2017 biography in English) was not the only Fellow or future Fellow of the Royal Society that Lantz was supplying with animals and collaborating with. He worked with Michael James Denham White (1910-1983, FRS 1961) then at University College, London, and more significantly with Harold Garnet ‘Mick’ Callan (1917-1993, FRS 1963) on the cytogenetics of his hybrid newts. Newts have large chromosomes and are particularly suitable for studying meiosis; the number of chiasmata between pairs can more easily be counted. After Lantz’s death, Callan and Spurway continued their collaborative work on meiosis in hybrids between different geographical ‘races’ of Triturus cristatus. I have written elsewhere about the people Haldane recruited in the late 1940s to work with Helen at University College London in breeding newts (and fish). The story can be found here

Not apparent from the biographies was the many years needed for Lantz’s cross-breeding experiments. From an initial breeding in 1944—in wartime Manchester where Lantz was, as Haldane noted, appointed by de Gaulle as representative of the Free French Forces—the young newts only reached maturity in 1947 and those from back crosses made in that year in 1949-50. Fruit-flies, with a generation time of 1-2 weeks, they were not.

Interest in what determines the skin colour and pattern in amphibians was high in the first half of the 20th century. Paul Kammerer—another protégé of Wolterstorff—had claimed, certainly erroneously and probably fraudulently, that the pattern of stripes and spots on salamanders was determined by the environment. The examples he provided were soon shown to be of salamanders from different parts of the geographical range and that the major differences were genetic in origin. The physiological, i.e. short-term, mechanisms that cause a frog to change colour when moved, say, to a pale substrate, were also becoming clear. Lantz set out to determine what effect a light or dark background would have on larval salamanders and whether changes in colour or pattern were carried into adulthood. He began this work in 1938 on Triturus cristatus. His paper was published posthumously in Haldane’s journal, Journal of Genetics in 1953†.

Lantz also showed that other claims of Kammerer’s, oviparity in viviparous lizards and ovoviviparity in salamanders, were part of the normal plasticity of the species involved in different parts of their geographical range and not novel, acquired, heritable traits.

It was not only his success with newts that attracted attention. He was also breeding the Painted Frog, Discoglossus pictus, at home in Manchester. Alan (Sir Alan from 1968) Parkes (1900-1990, FRS 1933) and Hilda Bruce (1903-1974) (of the famous Bruce Effect in mice) of the National Institute of Medical Research got to know of this and were keen to explore the potential of a species which breeds spontaneously in the summer or can be induced to breed in the winter under laboratory conditions. Lantz supplied them with frogs and he wrote a note as an annex to their paper which described how the adults and tadpoles were kept and bred. Neither Lantz nor Bruce and Parkes succeeded in rearing the metamorphosed young. This problem, common at the time, was almost certainly attributable to deficiencies of calcium and Vitamin D. Lantz did though release young into his garden where they thrived and spread into neighbouring gardens.

Also in touch with Lantz was C.H. Waddington (1905-1975, FRS 1947) who had earlier used Discoglossus pictus for pioneering work in developmental biology. Waddington, then in Edinburgh, was taking Lantz’s advice on breeding the frogs in 1951.

Lantz did not abandon his classical herpetology nor his keeping and breeding of many different species of lizards and amphibians while in Manchester. Far from it. He collected in the Mediterranean region and the Pyrenees. He was clearly in close contact with H. W. Parker (1897-1968) at the Natural History Museum in London; some of his specimens are in the collection.

Thus, while emphasis has been on Lantz’s contributions to classical ‘museum’ herpetology, he was a more significant figure in British science.  Capitalising on his lifelong interest and success in keeping and breeding reptiles and, particularly, amphibians in captivity, he had an important enabling rôle in the research of leading British scientists working on evolutionary genetics and cytogenetics in the mid-20th century.

Louis Lantz was described by Parker in a short obituary for the journal Copeia as one of the outstanding figures in herpetology. I agree.

*There is an error in the text in that the animals are referred to as T. cristatus marmoratus rather than T. cristatus x marmoratus. Smith ought really to have said that he was showing the best available data to make his point on growth rate and the fact they were interspecific hybrids was not germane.

†The results were clear. White or black background (on which the larvae turned lighter or darker respectively) had no effect on the dorsal spot pattern after metamorphosis but the lightness or darkness of the ground colour could be changed with a change in background. For ventral coloration, the results were different. A white background suppressed while a black background promoted the development of black markings. The ventral coloration and patterning could not be reversed by changing the background in adults.

A list of Lantz’s publications is included in the 2017 biographies. However, because there seems to have been confusion when a publication in Proceedings of the Royal Society was listed and scanned for online viewing, a note of his appended to but part of a full paper has been shown as a separate publication. The correct reference is:

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

These are the two biographies I refer to in the text. The shorter and earlier one is:

Anon. 2007. Lantz, Louis A. (1886-1953). In Contributions to the History of Herpetology Volume 2, edited by Kraig Adler, p 139. Society for the Study of Amphibians and Reptiles.

The 2017 biography has been published twice, once in the USA in English and in a slightly longer form (with an additional author) in France in French:

Ineich I, Doronin I. 2017. Louis Amédée Lantz (1886-1953): The Life and Work of an Alsatian Pioneer of European Herpetology. Herpetological Review 48, 93–108. 

Ineich I, Doronin I, Lescure J. 2017 Vie et œuvre de l’Alsacien Louis Amédée Lantz (1886-1953), pionnier de l’herpétologie européenne. Bull Soc Herp Fr (Bulletin, Société herpétologique de France) 162, 55-106.