Anthrax in Africa, in Britain and in the lab

Two interesting recent papers reminded me of being woken in the night by a clattering on the door, people being roused and muffled voices. The next morning my bleary-eyed mother and grandmother told me it was the police who came knocking. An animal had died of anthrax on a local farm occupied by a cattle dealer and they had come to requisition coal, then strictly rationed, in order for the carcass to be incinerated without delay. They had to burn it, my grandmother told me, as I probably asked too many ‘why’ questions, because anthrax got into the soil and could infect and kill animals and farm workers years later. That would be in the late 1940s when I see from DEFRA that there were 119-344 outbreaks per year between 1945 and 1950 (anthrax is almost unknown on British farms now; the last, isolated, outbreak was in 2006).

The first paper† I read was on how some hoofed herbivores are attracted to anthrax-infected carcass sites in Etosha National Park in Namibia, thereby enabling anthrax to infect new victims. Despite the rapid removal of soft tissues by scavenging birds and mammals, a carcass was found to improve the soil and vegetation around it. The overall finding was that, initially, herbivores avoided carcass sites, then were attracted to them and finally showed no preference. Bacillus anthracis spores were found in the grass from these sites for up to two years after the animal’s death.

In the authors’ words:

The results suggest that for zebra, springbok or wildebeest encountering a site where a zebra has died within the last year, an animal is up to four times more likely to graze at the potentially infectious carcass patch than at a random grassland patch nearby…Carcass and control patches seemingly became indistinguishable again for grazers from 1.5 to 2.5 years after death of the focal animal. This seems to match the time scale of carcass effects detected in grass biomass and nitrogen, and early preference for grazing at carcass sites would significantly increase the odds of anthrax transmission from grazing in the first year after death.

There were, however, interesting differences between the herbivore species that are found in Etosha. Gemsbok showed no clear foraging preferences; this species also had a low incidence of confirmed anthrax cases (1.3% of cases between 1968 and 2011) while constituting 13.5% of the herbivore population as estimated by aerial survey in 2012.

A paper* from the same stable adds another level of operation of anthrax. When the grass preferred as forage by the zebra was grown from seed in an experimental plot, the addition of anthrax spores enhanced the establishment of grass seedlings by about 50%. When very small amounts of blood were added, the height of the grass was increased. Anthrax had no effect on height and blood had no effect on the establishment of seedlings. (No other carcass constituent was tested and it is possible, of course, that body fluids in general seeping into the soil could contain the constituent(s) responsible for the effect of blood.) Therefore it seems that anthrax in the soil acts to secure the rapid regeneration of grasses and the attraction of herbivores to carcass sites. Some constituent of blood then makes the grass crop more luxuriant and even more attractive to grazing herbivores. Natural selection has really equipped B. anthracis to exploit its hosts.

The other paper I read was the Biographical Memoir on Harry Smith FRS (1921-2011) by Alan Rickinson FRS‡. Harry Smith was always direct, to the point, of rapid judgement and, therefore, a delight to sit with at dinners. The last conversation I had with him, as he headed off to Birmingham, was about a scientific institution. ‘That place has gone down hill badly’, he said as he shot off into the night. However, I digress. Harry solved how anthrax kills. No lethal toxin had been identified in vitro. Only by working in vivo was he and his colleagues able to determine the mechanisms. Even then the toxin was not simple. There were three components, all non-toxic when tested separately, but together responsible for the devastating effects of anthrax on the body. Rickinson writes:

The discovery of the anthrax toxin was a significant advance that, with the benefit of hindsight, marked a turning point in the field of microbial pathogenesis.

And all that has been done since I was awoken during the night and introduced to the lethal world of anthrax.

Bacillus anthracis
https://phil.cdc.gov/phil/home.asp

These Plains or Burchell's Zebra (Equus quagga) are in the shade, not long before sunset, in Botswana in 2001

† Turner WC, Kausrud, KL, Krishnappa YS, Cromsigt JPGM, Ganz HH, Mapaure I, Cloete CC, Havarua Z, Küsters, M, Getz WM, Stenseth NC. 2014. Fatal attraction: vegetation responses to nutrient inputs attract herbivores to infectious anthrax carcass sites. Proceedings of the Royal Society B 281: 20141785. http://dx.doi.org/10.1098/rspb.2014.1785 

*Ganz HH, Turner WC, Brodie EL, Kusters M, Shi Y, Sibanda H, Torok T, Getz WM. 2014. Interactions between Bacillus anthracis and plants may promote anthrax transmission. PLoS Neglected Tropical Diseases Jun 2014; 8(6): e2903. Published online Jun 5, 2014. doi:  10.1371/journal.pntd.0002903

‡Rickinson, A. Harry Smith CBE. 7 August 1921-10 December 2011. 2014. Biographical Memoirs of Fellows of the Royal Society 60, 399-411

Newts in Britain: This is What Happened

I wrote the other week of protection of the Great-crested Newt (Triturus cristatus) in Britain as a result of habitat loss, and, for habitat loss, read the filling-in and building-over of suitable ponds. The local Common or Smooth Newts (now Lissotriton vulgaris, then Triturus vulgaris which in the breeding season were abundant in local ponds, slow-moving streams and ditches, got me interested in zoology. To illustrate what has happened to those habitats since 1960, I show the following two images from Google Earth of places I used to find newts. In one, the slow-moving stream has been culverted and, in places, built over. In the second, the pond has disappeared and the area is covered in football pitches. Local authorities just loved to 'tidy' remaining wild places, even if a habitat was not actually built over, and as a result ponds, streams and ditches which were ideal for children to explore have gone.

A small stream ran from right to left across this land in the 1950s

The pond that was here is now part of a football pitch

I never found a Great-crested Newt in this same area. However, I was intrigued to find the result of a survey for some building scheme that showed such an animal had been found in the past few years in the garden of a house. A note on the survey said that the site had been cleared in 1991 and the newts moved elsewhere. In other words, the pond had been filled in as houses were built. I never found this pond with its Great-crested Newt when I was looking in the 1950s and early 1960s. It must have been on an area of land that was allotments, nurseries and orchards (and described as such on the 1935 land-use map). I can see the land in my mind's eye now but I can only think it was at behind one of the large houses that stood back from the road and surrounded by orchards. Sadly, my friend at primary school who scrumped apples from these orchards (when not playing cowboys and indians with cap pistols and home-made tomahawks) and who might have been able to remember a pond there died many years ago.

However, moving on from my annoyance at not having found a pond that held Great-crested Newts in the 1950s, I do have a question: Is there any evidence that catching and moving Great-crested Newts from areas chosen for building 'development' have any effect on the size of the population? Or is translocation just 'greenwash', in other words, a load of eyewash that obfuscates conservation and protection and thereby permits builders and public bodies to pay lip service to conservation while filling in another pond?

Antarctic Zoology Loses Two Stalwarts: Dick Laws and Bernard Stonehouse

Closely following the news of the death of Dick Laws on 7 October, I saw the notice in The Times this week that Barnard Stonehouse had died on 12 November. Both started out with the Falkland Islands Dependencies Survey in the late 1940s and Dick later became Director of the successor body, the British Antarctic Survey. Both were born in 1926.

For followers of this blog, Bernard Stonehouse collected a series of Emperor Penguin embryos in 1949, as I described in In Search of a Penguin’s Egg. Why?...What happened to Nelson Norman's 1959 embryos? on 3 July this year.

FIDS and BAS, to my certain knowledge, exemplifies spirit of scientific collaboration that I hope continues. Workers in Antarctica could not have been more helpful in collecting, storing and bringing back material.

Dick told me that I must go to the Antarctic. I did. He was right.

Heading south to the Lemaire Channel. 30 January 2005

Salt Glands in Iguana iguana. Somebody got there first

After Knut Schmidt-Nielsen described his discovery of salt glands in marine birds in 1957, other scientists and naturalists realised that they had seen the phenomenon earlier but had no appreciated what they were seeing. In the early 1960s, salt glands were discovered in terrestrial lizards (the salt gland in the Galapagos Marine Iguana was described by Schmidt-Nielsen and his friend Ragnar Fänge in 1958).

In 1963 Knut, with Arieh Borut, Ping Lee and Eugene Crawford in a paper in Science (142, 1300) reported:

A specimen of the tropical lizard Iguana iguana which was kept in the laboratory was occasionally found with white incrustations around the nostrils. The material was water soluble and preliminary analysis showed large amounts of potassium as well as sodium. Closer observation of the lizard while kept in a glass-walled terrarium revealed that the animal had the habit of pushing its nose against the wall thereby leaving a salt deposit on the glass.

A few weeks ago I was looking for information on Mrs Kathleen Pickard Smith for my other blog on the history of keeping reptiles and amphibians. She wrote a popular book on her experiences during the 1950s, Living with Reptiles, which was published by Thomas Nelson & Sons of Edinburgh in 1961. I read the book in 1962 and eventually gave it to the Zoo library. On reading bits again while I was scanning it,  I find she noted the following about her iguana, 'Ig':

Never a fast or a hunger strike to alarm us—true, he sneezes quite a bit in cooler weather, which leaves a chalky deposit on his nostrils and on the glass of his cage, but this is quite natural.

So, again we have an observation of salt glands in action, this time in a terrestrial lizard, before the observer could appreciate what had been observed.

#180977731 / gettyimages.com

Chinchillas in Zoos, and early import

AJP Photograph

Long-tailed Chinchillas (Chinchilla laniger) appear to be in deep trouble in the wild. However, I have not been able to find any definitive evidence on their status that is not nearly 20 years old. There are, of course, lots of domesticated chinchillas which have their origins in this species (see my earlier post). The few zoos I have visited in recent years seem to show them as domesticated ‘educational’ animals rather than in a nocturnal house setting of naturalistic habitat or in the size of colony that might occur in the wild—in other words, an exhibit that would really play an ambassadorial role in drawing attention to the parlous state of this species in the wild. I thought I had read somewhere that a British Zoo once had such a colony of chinchillas. Then the Bartlett Society Journal dropped on my desk. Russell Tofts in his article on the history of Jersey Zoo (now called, euphemistically in what must be another example of political correctness and focus-group inspired marketing strategy, Wildlife Park) provided what I had been trying to remember, under the year heading 1966:

In Jersey, an airy block building measuring 10 feet by 12 feet, well-lit by natural light, was constructed for an initial colony of twenty-five animals. By the end of a successful breeding season, the colony had risen to thirty-one (including seven animals that had had to be removed).

I would not think the Jersey effort would have been successful as an exhibit. Chinchillas really do sleep all day and a reversed daylight system would be needed to see them on the move. Nor do I underestimate the difficulty of setting up a colony in the first place. Adult chinchillas take very unkindly to being introduced to new potential cagemates; very unkindly is an underestimate.

In the 1950s chinchilla bubble in UK, when gullible individuals thought they were would be able to make their fortunes by breeding chinchillas for fur, and prices of live chinchillas rocketed, pairs of chinchillas were advertised at from £50 in 1957, the equivalent of £875 today. I think these chinchillas were from imported stock that was probably derived from the Chapman collection which was taken to California in 1923.

Advertisement: Cage Birds 21 February 1957

However, Britain had seen chinchillas before then, both in zoos and private collections. I came across this mention in an article by HD Astley in the September 1913 issue of Avicultural Magazine

Mr Goodfellow [Walter Goodfellow, 1866-1953, the renowned collector] brought home from Chili [sic], landing in the first week of July, some birds which were a puzzle to those who had never before seen them. Mrs. Johnston very kindly invited me to go to Burrswood on the day after their arrival. Incidentally, the principal interest was not birds, but Chlnchillas; which I preferred infinitely to see in their skins, rather than the latter made into muffs and boas, etc. As however, they are not birds, I must refrain from studying them too closely, at any rate in the Magazine suffice it to say, they are most fascinating, and a pearly-grey coated Chinchilla, when tame, would make a charming pet. 

I do not know whether any of the chinchillas imported into Britain survived until after the Second World War. It is possible that they did because the super-rich of the day kept extensive collections, particularly of birds, and it is doubtful if records of what many of them had and bred were kept or preserved.

Worst scientific article title of the year?

It used to be an unwritten rule that the title of a scientific paper should inform the reader what the work described and the species or group of animals from which data had been obtained. For some journals, the editorial policy was to insist on the latter. But in these smart-arse title days, I am left wondering what a paper is about. Looking through the contents of Proceedings of the Royal Society B, as I do with each issue, I often find the title actually obscures rather than informs the reader of the content. But this one really takes the biscuit: Parental risk management in relation to offspring defence: bad news for kids. No, it is not about young goats; it is not even about young children. It is about a study of nest defence behaviour in Blue Tits.

I presume the authors, judging by the last sentence of their abstract, are trying to draw attention to possible extrapolation of their findings to ‘living beings, including humans’  but for that claim to form the title through a slang word for human children is a travesty. The work is about the behavioural strategies employed by Blue Tits against threats by predators to them and their offspring. So why not say so? It makes the work no less and no more important.

Bryde's Whale

We have seen Bryde’s Whale in several parts of the world. When one is seen, the Brits shout ‘brides’ across the deck while the hispanophones (in the Galapagos, for example) shout ‘bridies’, pronounced as the Scottish pasty. I now find we are all wrong.

Bryde’s whale is named after the Norwegian, Johan Bryde (1858-1925) who founded the whaling industry in South Africa. The pronunciation is something like ‘brude’s’ or 'brudess' (I can never get my tongue round Scandinavian pronunciation or its rules, despite being born in the old Danelaw part of England where streets are still ‘gates’. So next time you are whale-watching you can smugly shout ‘Brude’s’ across the deck, while the rest of the crowd wonder what on earth you are talking about.

I also had not know, until I started looking it up, how much uncertainty there is on the taxonomy of Bryde’s Whale and how much more needs to be known before more definitive pronouncements can be made. The IUCN Red List has the details of the various forms that go under the heading of Bryde’s.

Balaenoptera edeni (Anderson, 1879) is the scientific name in use because Bryde’s Whale, described from specimens killed off South Africa by Olsen in 1913 and named B. brydei, was considered to be synonymous with the form described by Anderson which was collected just off the shore of Burma. The original edeni (Eden’s Whale) is thought to be smaller at maturity than ‘ordinary’ Bryde’s whale and has been called the ‘pygmy’ version; some have now separated the two into the original two species; some consider them subspecies.

Bryde's Whales off Mirissa, Sri Lanka, 26 November 2013                                                           AJP Photograph

There have been other findings of similar whales that further confuse the issue but the point of mentioning the two forms in the current context is that in the northern Indian Ocean, off the southern tip of Sri Lanka, we saw Bryde’s Whales on both days we were there in November 2013, along with the Blue Whales, Orcas and Spinner Dolphins. I now see that there is a claim, with a video on Youtube and articles in the Sri Lankan press, of a possible sighting of Eden’s Whale, the dwarf or pygmy form or separate species, off Sri Lanka. I saw a number of critical comments as to this identification but they seem to have disappeared when I looked for them again. But this observation illustrates how much there is still to find out about marine mammals and how difficult research is in this field.