Diane McTurk (1932-2016): The ‘Otter Lady’ of Guyana

Diane McTurk with two of her
otters. From Wilderness Explorers,
the ground agents for many
wildlife tours in Guyana

The death in Guyana of Diane McTurk in December 2016 went unreported in Britain. Lack of coverage was surprising in view of her family’s appearance in two works by national treasures: Gerald Durrell’s Three Singles to Adventure published in 1954 and David Attenborough’s BBC Zoo Quest to Guiana in 1955 with the book published in 1956. By contrast, in Guyana and the Caribbean her death was reported widely.

In her later years Diane (pronounced Dee-Ann) became well known for establishing in 1983 a tourism business at the family’s Karanambu ranch in the Rupununi grasslands of Guyana and for rearing rescued orphaned Giant Otters (Pteronura brasiliensis). Not only did she learn how to rear them but successfully reintroduced many of them to the wild. When we were at Karanambu in 2006 Diane told us that the otters had been—and to a some extent still were being—hunted, the orphaned young being left to die. She reared over forty with, fortunately, the supply eventually drying up. The hand-reared otters became incredibly tame, following Diane or her helpers down to the river for a swim, a play with the children watching their mothers washing clothes and to fish. The otters got through enormous quantities of fish caught each day at the river. While the otters were at the river a sharp eye was kept for the pack of wild otters. They are fiercely territorial and would have killed the hand-reared interlopers. A call from Diane soon had them back to heel and they were lead back to the lodge where they had a cosy box to sleep in.

Diane McTurk had an interesting life flitting between a life in Guyana and England. Schooled as an actress but realising she did not have the talent required, she worked in public relations for the Savoy Hotel. And that explained why staying at Karanambu was such an easy experience. The brick building and thatched roof may have been basic but there was everything there that a guest might need—it was a Savoy experience combined with country house weekend dining—hundred of miles from the nearest city. A variety of public relations and business development jobs in Guyana and London followed, as for a time she flitted between the two countries. She was though firmly Guyanan having been treated, she said, by her London contemporaries as just a ‘colonial’.

Politically active—and judging by the photographs and literature in our quarters—a strong supporter of Cheddi Jagan (1918-1997) who fell foul of one of the periodic madnesses of British and US foreign policy in the 1960s, Diane also, it is reported, raised support for the defence of those accused after the Rupununi Uprising of 1969 and who were eventually acquitted.

But what links talking to Diane in the searing heat of the gravel-covered yard at Karanambu (kept clear of plants to reduce the number of biting insects near the buildings) and a former mining village twenty miles inland from where I am writing this? The first McTurk in what was then British Guiana was Michael. Sir Michael McTurk was born in New Cumnock, Ayrshire in 1785. He graduated in medicine from the University of Glasgow in 1810 to become principal medical officer in British Guiana for 34 years. He was responsible for ensuring that Georgetown, the capital and centre of the sugar industry, had a water supply both for the human population and to irrigate the sugar fields. McTurk was concerned with the plight of the slaves in the country; he was knighted 1839 for his efforts on their behalf. After the passing of the Abolition of Slavery Act 1833, he brought in a local measure ensuring the full emancipation of the slaves. He died in 1844.

The next generation of McTurks was in Liverpool with Sir Michael’s son having married into a family of shipowners. On hearing the stories of his grandfather, the grandson, another Michael, took off in one of the family ships to Georgetown. That Michael, Diane’s grandfather, became Protector of the [Amer]Indians for the whole Essequibo region and her father Edward ‘Tiny’ McTurk—known for his association with Durrell and with Attenborough—was born at Bartica. After service in the Royal Flying Corps in the First World War, ‘Tiny’ McTurk decided he needed a proper job so joined the balata industry.

I had previously only associated balata with the covering of expensive golf balls for professionals (back-spin is easier to achieve but at the expense of distance) that were used until very recently. But I now find that In the 1920s balata was booming, being used to cover the underwater cables linking countries and continents, and it came from a tree common in Guyana and the West Indies, Manilkara bidentata. The latex-like material was tapped, like rubber, by cutting gashes in the bark and then left to coagulate in trays. Balata is tough, inelastic and water resistant but can be softened by heating.

So balata was big business and McTurk was given the job of finding somewhere suitable as a collection station. Karanambu did not flood in the wet season and McTurk established the balata station and cattle ranching there in 1927. Diane returned to Karanambu in 1977 and saw that diversification into tourism at a time of dwindling income from traditional activities was essential.

One of our fellow guests remarked as we left Karanambu in its ancient Land Rover in a remark that could have applied to Diane as to the vehicle: ‘They don’t build ‘em like that any more’.

Here is a very short extract from a video I took of Diane with one of her otters in March 2006:

You can see more on the unupdated website of the Karanambu Trust, set up by the McTurk family in 1997, with more information here, here, here and here.

NOTE ADDED 23 July 2021

Emmanuelle Wiecha, a documentary filmmaker based in Montreal tells me that the final Giant Otter Diane McTurk rescued and named 'Buddy' was transferred to the Jacksonville Zoo in Florida and recently sired two litters.

Alpha Helix: a floating laboratory for comparative physiology in the 1960s and 70s. What happened to her?

Anybody reading papers on how animals work from the 1960s and 70s cannot fail to notice that much of the work on certain topics, Bill Dunson’s research on sea snakes for example, was done on board the Research Vessel Alpha Helix in what seemed a series of idyllic expedition cruises in biologically interesting parts of the world. Later, there appeared to be no reference to Alpha Helix. What happened to her?

R/V Alpha Helix

Before looking at what happened after these voyages, it is worth considering her history. The driving force behind her funding, construction and operation was Per (‘Pete’) Scholander (1905-1980), the famous physiologist who worked on survival in the cold and at sea, as well as in other fields like plant physiology. Scholander was then at the Scripps Institution of Oceanography. In 1962 he succeeded in getting funding from the National Science Foundation of the USA (NSF). I am not sure whether the vessel was classified as a ship or a boat but although owned by the Scripps, it was funded throughout by the NSF and operated as a national asset.

The vessel was named Alpha Helix after the structure of proteins discovered by Linus Pauling. I cannot see why because the work done on board bore no relation to the chemical work of Pauling nor was it intended to. Reading between the lines I suspect some political motive.

In Scholander’s biographical memoir, Knut Schmidt-Nielsen wrote:

…in 1966 the ship started on its first cruise, the Billabong Expedition to the Great Barrier Reef. A National Advisory Board, initially chaired by Baird Hastings, evaluated applications for use of the ship. Over the fourteen years the ship remained in service as a floating physiological laboratory, expeditions went to Australia, the South Seas, the Amazon, the Antarctic, the Galapagos, the Bering Sea, and other sites. Several hundred scientists from all over the world have participated actively in these expeditions, and the records of Scripps Institution show that the work on the Alpha Helix has resulted in a total of 547 publications in recognized scientific journals—an impressive record for the relatively modest funds invested in the Alpha Helix.

Details of the various cruises and of the structure of the organisation set up to sort out who was invited and that to run the vessel can be found online (see below). Initially the participants were mainly US based (NSF grantees had priority) but the foreign scientist were on board for many of the cruises. In 1967 Dennis Bellamy (then in Sheffield and later in Cardiff) was one:

…I was asked to be the lead biochemist on Knut Schmidt Nielsen’s Alpha Helix expedition to the Amazon Basin.

So why was the whole concept scrapped in 1980? It seems that interest in using Alpha Helix had waned by the late 1970s—crazy as that sounds now. NSF support was withdrawn and the vessel was sold to the University of Alaska where it was used mainly for oceanographic work. After being in dry dock in 2004-2007, she was sold to a private company and then in 2014 to the Autonomous University of Mexico and based at the port of Ensenada. Alpha Helix is now an oceanographic research vessel. Indeed her whereabout can be traced on Marine Traffic under the name Buque Oceanografico Alpha Heli. This is where she was on 5 May 2018:

From Marine Traffic

Information on the history of Alpha Helix can be found here, here, here and here.

Schmidt-Nielsen K. 1987. Per Scholander 1905-1980. Biographical Memoir, National Academy of Sciences 56, 387-412.

An exotic day out for Sheffield zoology students - 1930s style

Also in the 1930s the first university students were admitted in groups, with a lecturer, at a reduced rate. At this time, for instance, the Sheffield University Zoology Department annually hired a passenger coach, which was slipped from the London express to deliver its complement of students for a day at the newly opened Whipsnade Zoo*.

The method of delivery of the students is interesting since it illustrates a long-gone railway operation. A slip coach (and sometimes coaches) was at the rear of the train. Some distance before the station a guard in the slip coach would pull a lever to ‘slip’ the coupling with the carriage in front, apply a little braking, to make sure the rest of the train would draw ahead and then slowly brake the coach to come to a stop at the station platform, while the express train steamed to its final destination. The whole operation was a routine on some routes but there were hairy moments and a notable crash (the driver thought the slip coach had not detached and stopped to check while his rear vision was obscured by smoke; the slip had detached and so ran into the back of the stopped train). There is a video of a slip operation here. At the end of the day though the slip coach must have been attached to a local train and pulled, presumably, to a station on the line at which it could be attached to the end of the train bound for Sheffield. 

Once at Whipsnade, our predecessors as students by thirty years might have sent a postcard like these shown below by Frederick William Bond (1887-1942) who was not a professional photographer but a member of staff of the accounts department of ZSL.

*Bullough WS, Hamilton F. 1976. The role of education. In, The Zoological Society of London 1826-1876 and Beyond. Ed. Zuckerman. Symposia of the Zoological Society of London 40, 223-231.

Achatina Snail: An invasive species in Hong Kong 2. My fruitless hunt for steroid hormones

In my last post, I mentioned that the accidentally introduced giant snail, Achatina, was very common in the gardens of the University of Hong Kong. The mid-1960s were the heyday of comparative endocrinology. Having established the presence of the same or closely-related steroid hormones from the adrenal glands and reproductive organs in all the vertebrates, the question was whether these steroids were present and working as hormones in the invertebrates. With such a plentiful supply of an invertebrate, in this case a mollusc, outside the lab door, I had the animals.

A well-established method to see which steroids vertebrate endocrine glands synthesise was to incubate the tissue with a radioactively-labelled compound in the early part of the biosynthetic pathway and see what was produced. I used the paper chromatography separation systems made famous by the late Ian Elcock Bush (1928-1986) in his book, The Chromatography of Steroids, published in 1961. We had a good set up for descending paper chromatography in Hong Kong and although newer thin-layer techniques were also in use in the lab, the Bush systems still had a lot to offer, especially for a quick look-see. The chromatography tanks were in a small back room of the old medical school building and Hong Kong being Hong Kong there was no need to heat the tanks. The smell of warm solvents greeted you at the door. It was a glue-sniffer’s paradise if an out and out fire hazard. The dangers inherent of inhaling industrial quantities of benzene fumes were also in the future.

Shandon Panglas chromatography tanks
are now museum pieces or, like this one,
for sale on eBay. This one lacks the trough
at the top for the mobile phase.

To cut a long story short, I could find no known adrenal steroids in the incubation fluids from several possible organs of the snail. Although we were not that interested in reproductive steroids I had run known a number of oestrogens and androgens standards as well. Again, nothing radioactive from the incubates ran in the chromatography systems with them. There were however, very small quantities of a few compounds that just might have been steroids of some sort. However, they were beyond my capacity to determine what they were. Indeed there seemed to be no chemical techniques available at the time that would have enabled me to do so.

The pilot trial on the snail of what after all was a cast-in-the-dark fishing expedition was the end of the line for my only foray into invertebrate life. Other, more productive lines beckoned.

I have though always wondered what those radioactive spots on a paper chromatogram were. Had I thrown the baby out with the bath water? Yesterday, though, I was gratified and breathed a 52-years later sigh of relief when I read of a similar early study on a different mollusc. Alexander Scott wrote in his first review of 2013 (see below):

In some experiments within this study, the gonads and hepatopancreas of this animal [Atlantic Sea Scallop, Placopecten magellanicus] converted up to 70% of added radiolabeled Pregnenolone and 17-hydroxyprogesterone into several metabolites. However, David Idler, who was probably the greatest steroid chemist of his time…was unable to identify a single one of these (apart from a trace of androstenedione)!

Those people working on fish endocrinology, incidentally, were scared of what David Richard Idler (1923-1996), then of the Fisheries Research Board of Canada, would have to say about their work. He was certain to spot any flaws in claims of chemical identification of steroids. He blew a fair number of claims—and their authors—out of the water.

Some time after my quick look-see I saw that several papers had been published suggesting that sex steroids but not adrenal cortical had been found in molluscs and that there was some evidence for some possible involvement in hormonal signalling. However, I had seen nothing to indicate a major rôle for steroid hormones. In order to become less ignorant on this matter I discovered two reviews by Alexander Scott which gathered all the information of steroids in molluscs and subjected the evidence to a pretty devastating analysis.

Historically, there was a problem with proving that a substance found in, or synthesised by, an organism was a particular steroid. Chemical techniques were simply not then available. There was considerable dissent on what was acceptable evidence of chemical identity. Those with a background in steroid chemistry, like David Idler, had the whip hand. Some would write a paper saying that they had identified the compound produced as hormone x because they had run it in two chromatographic systems along with authentic x; others insisted on using more systems, sometimes changing chemically the structure of the putative and known steroid. For studies on steroid synthesis from radioactive precursors, there was a gold standard: recrystallisation of the separated radiolabelled product with added pure compound to constant specific radioactivity but a lot of early work stopped short of this final step and even with its use there were traps for the unwary.

Looking back at the literature on vertebrate steroid hormones an awful lot of poor work was published. However, because evidence of identity was difficult to get, there was also bad luck. I remember being told of one case where radiolabelled product and pure sample ran together in 10 chromatographic systems; in the 11th they separated showing they were not the same.

Alexander Scott, a noted fish endocrinologist, in his two reviews has looked at all the evidence of the presence, formation and possible functions of steroids in molluscs. It is an important topic because of the environmental effects of anthropogenic discharge of hormonal steroids, their metabolites and their chemical analogues. This is how he introduced his first review (references deleted):

The question as to whether vertebrate steroids act as hormones in mollusks is a very important one. Many compounds that behave like vertebrate estrogens are present in the environment (so-called ‘endocrine disrupters’), and if they act in the same way in mollusks as they do in vertebrates then there is genuine cause for concern. The first reports of the existence of vertebrate-type steroids in mollusks appeared in the 1950s. Since then, all but a handful of the 200+ scientific papers and reviews that have been published in this area have a positive message (i.e. they conclude either that mollusks contain vertebrate steroids, are able to biosynthesize them de novo, appear to contain steroid receptor-like binding activity or respond in one way or another when exposed to vertebrate steroids). The sheer ‘weight of evidence’ would seem, on the surface, to make it an ‘open and shut’ case that vertebrate steroids are an important component of molluscan endocrinology. However, if one looks beyond the headline claims (i.e. essentially what is written in the titles and abstracts of many of the papers), a different story emerges – one in which most, if not all, of the positive evidence can be seen to be rather weak (in that the data are open to alternative interpretations). This review paper deals with the strength of the evidence for the presence of steroids in mollusks, for their biosynthesis and for the presence of steroid receptors. Another review paper deals with the strength of evidence for the biological actions of vertebrate steroids on mollusks.

Indeed, in Scott’s detailed analysis the evidence is weak. Steroids found by molluscs may have been taken up and sequestered from the environment, for example. Studies of the sort I did in Hong Kong in 1965-66 if apparently positive can have alternative explanations.

Scott’s second review was concerned with the effects vertebrate sex steroids on molluscs. This is what he concluded:

In assessing the evidence as to whether vertebrate sex steroids (e.g. testosterone, estradiol, progesterone) have hormonal actions in mollusks, ca. 85% of research papers report at least one biological effect; and 18 out of 21 review papers (published between 1970 and 2012) express a positive view. However, just under half of the research studies can be rejected on the grounds that they did not actually test steroids, but compounds or mixtures that were only presumed to behave as steroids (or modulators of steroids) on the basis of their effects in vertebrates (e.g. Bisphenol-A, nonylphenol and sewage treatment effluents). Of the remaining 55 papers, some can be criticized for having no statistical analysis; some for using only a single dose of steroid; others for having irregular dose–response curves; 40 out of the 55 for not replicating the treatments; and 50 out of 55 for having no within-study repetition. Furthermore, most studies had very low effect sizes in comparison to fish-based bioassays for steroids (i.e. they had a very weak ‘signal-to- noise’ ratio). When these facts are combined with the fact that none of the studies were conducted with rigorous randomization or ‘blinding’ procedures (implying the possibility of ‘operator bias’) one must conclude that there is no indisputable bioassay evidence that vertebrate sex steroids have endocrinological or reproductive roles in mollusks. The only observation that has been independently validated is the ability of estradiol to trigger rapid (1–5 min) lysosomal membrane breakdown in hemocytes of Mytilus spp. This is a typical ‘inflammatory’ response, however, and is not proof that estradiol is a hormone – especially when taken in conjunction with the evidence (discussed in a previous review) that mollusks have neither the enzymes necessary to synthesize vertebrate steroids nor nuclear receptors with which to respond to them.

As he points out, there are still a few cases where mollusc tissues appear to have converted known vertebrate hormones into others. Such work needs to be followed up to see if the entire pathway is present or if, fortuitously, an enzyme system in molluscs is doing the job of a specific enzyme in vertebrates.

What is really lacking in all the work is the integrated experimental approach in a single species. The work I first became of that seemed to implicate steroids in the reproductive physiology of a mollusc was that by Herbert Gottfried and Ralph Dorfman in the Giant Land Slug, Ariolimax californicus and published in a series of papers in the late 1960s. They seemed to have established a steroid-synthesising pathway similar to that in vertebrates that led to the production of androgens by the ovotestis. The work also involved experimental manipulation of possible signalling pathways. Unfortunately, this work does not appear to have been followed up but there appears, prima facie, to be a good experimental animal and an interesting and possibly important phenomenon to investigate. Previously, whilst at Sheffield, Gottfried with Oskas Lusis had a paper in Nature describing sex steroid production and metabolism in the eggs of a slug.

Herbert Gottfried* (1934-1977) and Ralph Dorfman (1911-1985) were both then at the Syntex research centre in Palo Alto, California and later at Applied Steroid Laboratories also in Palo Alto. Gottfried had been at Sheffield when I was a student but I do not recall meeting him. He had also been in Hong Kong in 1965 before we arrived introducing the use of gas-liquid chromatography for separating steroids. Ralph Dorfman was famous for his work on steroid hormones—he was elected to the National Academy of Sciences in 1978—including the development of the first oral contraceptives. He was President of Syntex Research. I spoke to him several times in January 1967 at the 3rd Asia and Oceania Congress of Endocrinology in Manila (the first scientific meeting of any sort I had been to) and he invited the Brits and Hongkongers there for drinks in his hotel suite. The bottle of Dimple Haig (named for the shape of the bottle and more popular in the USA and the far east than in Britain) I remember particularly well.

So while it is possible to agree with Scott on the inadequacy of a great deal of past work on steroids in molluscs, there is still the odd twinkle of light to suggest that the role of what might in the circumstances be termed vertebrate-type sex steroids in molluscan physiology can be entirely discounted. Another case of more work—avoiding the many pitfalls highlighted by Scott—being needed.

*Herbert Gottfried was born on 16 February 1934 in Vienna, Austria. In 1947 he became a British National along with his father Isak or Isaac, then a cafe manager in Brighton.  He married Patricia Elizabeth Wall on 31 March 1967 in Monterey, California. He became a US Citizen on 21 July 1970. He died in October 1977, aged 43.

UPDATED 2 OCTOBER 2023

Scott AP. 2012. Do mollusks use vertebrate sex steroids as reproductive hormones? Part I: Critical appraisal of the evidence for the presence, biosynthesis and uptake of steroids. Steroids 77, 1450-1468.

Scott AP. 2013. Do mollusks use vertebrate sex steroids as reproductive hormones? II. Critical review of the evidence that steroids have biological effects. Steroids 78, 268-281.

Achatina Snail: An invasive species in Hong Kong 1. History

The first animals I saw on arriving in Hong Kong on a dark November night in 1965 were giant snails, Achatina or Lissachatina fulica. They were in the dank area around the entrance to the block of flats in what was then called the University Compound. Even after twenty hours (including refuelling stops at Athens, Tehran and Delhi) on a Qantas Boeing 707 and the first sight of Hong Hong harbour from the vehicular ferry, the snails registered. They were big.

by Alexander C Jenner (Wikimedia Commons)

I soon discovered that these East African snails had spread widely in the tropics and were a considerable pest to farmers and gardeners. They were first noticed in Hong Kong in 1941 shortly before the Japanese Invasion in December. Since adults were found it was estimated that introduction occurred around 1937. Laying thousands of eggs over a lifespan of 10 years it is not surprising that its population and range increased rapidly.

The photograph in Jarrett's article
Hong Kong Naturalist vol. 2, 1931

They were first noticed by Vincent Hubert Charles Jarrett (1895-1973), a journalist on the South China Morning Post who was also a naturalist. At the time of the Japanese invasion he was Assistant Editor. Gwulo has a photograph of Jarrett in the 1941 here. He wrote numerous articles, including nature notes, for the newspaper and also for the Hong Kong Naturalist. He described the spread  of Achatina through Malaya and Singapore (he was born in Malacca) where it seems to have been introduced as a food for ducks. He also noted that it had been found in China by Herklots while on a visit to Amoy (now Xiamen) in 1931. Before the snail’s arrival in Hong Kong he raised a vital question:

Latest information from Malaya is that the snails are now found in increasing numbers everywhere, and even wander over the golf courses, where the chagrin of a player whose ball is stopped by a giant mollusc in the grass may be imagined. It is not known whether the question has yet arisen about counting Achatina fulica a natural or artificial hazard. It may be hoped, as a conclusion to this note, that the question will never have to be debated on one of this Colony's courses!

After release from internment at Stanley, Jarrett travelled to Britain in October 1945. I do not know whether or not he returned to Hong Kong. In 1959 he was appointed OBE for his services as ‘Editor of Press Summary’ at the British Embassy in Oslo. He died in Norway in 1973.

Geoffrey Herklots, who remained in Hong Kong as a member of the government after internment, brought Hong Kong up to date with the Achatina pest in an article for the South China Morning Post on 22 May 1946. He reported the snail was now well established on Hong Kong Island. He proceeded to give advice on how it could be killed by gardeners. With characteristic energy he held snail hunts:

On May 19, 126 snails weighing 6-lbs. were collected at Sookunpo; on May 18 and 19 330 snails weighing 20-lbs. at the Protestant Cemetery, and on May 18, 94 weighing 4-lbs. at Government House.

He ended:

These snails are edible. There is a pile of hundreds of empty snail shells at Government House. The obvious inference is that the former Japanese Governor or his staff, regarded them as a delicacy…

It is now known that Achatina snails carry a whole host of human parasites. There will be survivors of the Japanese occupation and their families hoping that a few of the more nasty ones attached themselves to the intestinal walls of the then occupiers of Government House.