In The Lazarus Snail’s Tale, I wrote about the climate change-caused extinction of an island snail, which turned out to be nothing of the sort. Leaving aside that the climate data was thin to the point of non-existent, the main problem with the claim was that the snail was not, in fact, extinct.

Thus another “It was climate change wot dunnit” story went into the bin, or it did for those of us who were paying attention.

I wrote about another such in The Golden Toad’s Tale. (Though this species is, sadly, deceased.)

But to go extinct, you first have to pass through the stage where you are endangered. Your population is sliding downwards, but you still exist; the golden thread holds. After the fact, it matters why the extinction happened, as a lesson. It also matters why a population is sliding down through abundance categories, from scarce to rare to endangered, or distributional ones, widespread to restricted to local – because here there is still time to do something to salvage the situation. Naturally, as a species you can be common, but in a very restricted area, such as an oceanic island. This is no protection against precipitous decline; the overall population is low, and all eggs are in the same basket.

Now, regarding snails on oceanic islands, they are a conservation disaster. What tended to happen in pre-historic times was one or a few colonisation events, and the lucky snail species that arrived on the remote island (probably rafted there by debris, washed down a river from a “nearby” continent) subsequently underwent adaptive radiation, so one colonising species became ten, or more, endemic species.

Next, humans arrive on the scene, and far before carbon dioxide was even a gleam in Al Gore’s eye, we went to work. Not that anything was deliberate at the beginning. Other things were more important, and conservation didn’t even exist. So if we needed wood, we destroyed forests. Goats were released, so that they could breed, and be eaten on a ship’s return years later. Rats came by accident. And so on. By the middle of the twentieth century, a series of snail introductions went on, accidental or deliberate. We had the giant edible snails, and then, when they started throwing their weight around, we had the carnivorous rosy wolfsnail Euglandina rosea, as mentioned in the Lazarus Snail’s Tale. These found the indigenous gastropods more to their liking than the giant rubbery introduced species they had been sent to hunt, and consequently the local species were wiped out by the dozen. (Actually, hundreds of species of land snails on oceanic islands have gone extinct in historical times.)

The Guardian enters the Bermuda Triangle

With that as a primer, today came news of a success story in island snail conservation:

Bermuda snail thought to be extinct now thrives after a decade’s effort

It was a familiar tale of direct human influence, whether intentional or unintentional, and a last-minute reprieve, thanks to strenuous efforts by conservationists. Or was it? Not entirely, not according to the Guardian:

The snails, which are only found in Bermuda, had been hit by global heating and habitat loss, but their decline was accelerated by the introduction of predatory “wolf snails” and carnivorous flatworms, which ate the smaller native species.

(Thank you to Mark for reporting this disgraceful line by our friends, those liars for Gaia, at the Guardian.)

They just couldn’t help themselves, eh? They just had to shoehorn in “global heating,” without which no bad event would ever happen. Now wait a minute, I hear you cry. Just give them a chance. Maybe, this time, they’re right.

Well, they’re not. Euglandina was introduced to Bermuda between 1955 and 1972, by which time those making the introductions ought to have known better. [Even the Guardian might admit that this pre-dates the era of “global heating,” making their statement a nonsense, even if climate had anything to do with anything.] Of the series of introductions, Cowie et al (2026) say:

In the Atlantic, Euglandina, as well as G. quadrilateralis and G. kibweziensis, have only been introduced to Bermuda, from Hawaii between 1958 and 1972. These introductions were intended for control of two other introduced snail species, Rumina decollata, accidentally introduced in the 1870s with imported plants and a facultative snail predator itself, and Otala lactea, introduced initially for food in 1928 but escaped; both became agricultural pests. The intended control by Euglandina in particular was not successful, but the drastic decline of species in the endemic genus Poecilozonites was attributed to it.

Cowie et al, references removed for clarity

[G. quadrilateralis and G. kibweziensis are other predatory snails.]

Of 11 species of Poecilozonites, found nowhere else but Bermuda, only 2 remain. The larger of the two was apparently thought extinct, but was re-found in an old alleyway in 2014. Naturally, the alleyway habitat was destroyed for development, but snails were collected and a breeding programme begun, at the Zoological Society of London, and Chester Zoo. The smaller species was collected earlier, and was “extinct in the wild”.

Here (page 9) you can read about the breeding and release of Poecilozonites. A journal (all right, a newsletter) called Tentacle has got to be worth a read, right?

The larger species has been released on islets around Bermuda, that are free of Euglandina and chums: Nonsuch Island, Hall’s Island, Trunk Island, Nelly’s Island and Saltus Island. (As well as two sites on the main island). The smaller species has been released on Nonsuch, but in a more controlled way, with protective enclosures. The idea, I’m sure, is to have populations on as many safe islets as possible. But the total area occupied is measured in hectares, rather than square kilometres. I suppose the thought has not occurred to the Guardian that, if “global heating” really is the problem, then there is not much point starting new populations… in exactly the same place.

Finally, the IUCN Red Listing for the larger snail makes no mention of climate change, or even “global heating.” Note that the assessment pre-dates the reintroductions, being dated to 2019. Note also that while the IUCN used to scrupulously avoid blaming climate change for anything, they have let their standards slip recently; nevertheless, they do not blame climate change for this snail’s problems.

The only known extant subpopulation of this species occurs on Port’s Island, where its continued presence is threatened by accidental introduction of invertebrate predators, mainly Euglandina rosea and terrestrial flatworms (e.g., Bipalium vagum). These predators are believed to be the reason for the demise of the species from the larger islands of Bermuda and could relatively rapidly spread throughout the small (7.6 ha) Port’s Island.

IUCN Redlist

Please, Guardian, rediscover your principles.

/message ends

PS. Poecilozonites was the subject of Stephen Jay Gould’s doctoral thesis.

PPS. The featured image is from Gould’s research on Poecilozonites. It’s the larger of the two extant species.

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19 Comments

  2. “Global heating” (aka mild warming) might, just possibly, be responsible for the demise of some species, but it’s infuriating to see it included in almost every story of this type. Guardian journalists, it seems, include it without thinking, and without evidence, because they are programmed this way. Whatever happened to inquisitive journalists? Whatever happened to fact-checking?

    Liked by 1 person

  3. I’m sorry Mark, but global warming is NOT the correct term; to be scientifically accurate, it should be “global heating”:

    “Global heating” is a more accurate term than “global warming” to describe the changes taking place to the world’s climate, according to a key scientist at the UK Met Office.

    Prof Richard Betts, who leads the climate research arm of Britain’s meteorological monitoring organisation, made the comments amid growing evidence that rising temperatures have passed the comfort zone and are now bringing increased threats to humanity.

    “Global heating is technically more correct because we are talking about changes in the energy balance of the planet,” the scientist said at the UN climate summit in Katowice, Poland. “We should be talking about risk rather than uncertainty.”

    And if we want to be really scientifically accurate, the changes in the energy balance of the planet which have occurred over the last 25 years are dominated by an increase in penetrative short wave solar radiation (due to a decrease in low level cloud cover) which, ironically, has resulted in an increase in outgoing long wave infra-red radiation – not a decrease, as predicted by climate models predicated on increasing GHGs. So the source of “global heating” for the last 25 years has got nothing to do with ‘climate change’ aka the ‘climate crisis’ aka the ‘climate emergency’ aka ‘climate breakdown’ and everything to do with changes in cloud cover and distribution, almost certainly due to natural climate variability.

    Of course, as we all know, attempts to be strictly scientifically accurate, but only when appearing on sites such as this, and which might tend to cast doubt upon the Settled Science and ‘experts’ like Professor Richard Betts, are otherwise known as ‘climate misinformation’ and should be censured by the EU and the UN. But I’m pretty sure this all goes over the extendable eye tentacles of Bermuda snails whose only concern is to slime comfortably, eat, sleep, breed and not be eaten.

    https://www.theguardian.com/environment/2018/dec/13/global-heating-more-accurate-to-describe-risks-to-planet-says-key-scientist?CMP=share_btn_tw

    Liked by 3 people

  4. Betts says: “We should be talking about risk rather than uncertainty”.

    This is precisely the problem I have been blathering on about here for the last 10 years. Because Betts is a climate science expert we assume he is an expert on risk science. So, when he comes out with nonsensical statements like that, we are supposed to just nod approvingly. But there is not a risk scientist on this planet who doesn’t understand that it is impossible to talk about risk without first talking about uncertainty. No understanding of a risk is possible without a firm grasp of the uncertainties. What he has just said is pure twaddle. He might get away with that sort of vacuous sloganizing whilst mingling amongst his climate science colleagues, but were he to say that at a risk science conference, people would slowly shuffle away from him as though he had just farted.

    Betts says we need to be technically accurate in what we say? That is to larf!

    Liked by 4 people

  5. Dougie, as you suspect, it is sometimes difficult to prove that a species is gone. For some like island snails, it’s not too hard, because the area to search is not large. For the golden toad, it was more difficult, with a larger potential range. But this species returned to known ponds to breed, so that if you go looking at breeding time, you can tell if there are any around. None have been seen for a long time. There is a chance that it is still out there somewhere, but it’s a miniscule one.

    Liked by 1 person

  6. Speaking of the havoc caused by introduced species…

    I hope my frogs* have better luck breeding this year. Last year I reckoned that a record-breaking four thousand tadpoles were in a pond that’s not much bigger than a bath yet I didn’t see a single froglet hopping through the grass in the months that followed. Some of the froglets must have survived but I think most of them were eaten by pheasants that visit/inhabit my garden after being released on a shooting estate across the road. The pheasants can be very cute (one of last year’s hens was insanely tame) but they do a lot of damage. I think they also eat slow worms, which I haven’t seen here for five or more years. (Bloody climate change!)

    Pheasant releases should be banned. The poor things are factory-farmed then released to be shot then those that aren’t shot (half of them?) go around snaffling frogs etc until they get run over while messing around in the middle of the road and most of those that do get shot don’t get eaten, they get chucked down old mine shafts or whatever.

    ===

    *I heard at least two frogs croaking outside the bedroom window at 4.30 this morning. I think that’s quite early in the year. (As it happens, I was reading Jit’s article about the Golden Toad when they started.**)

    **Another coincidence. A few minutes after I typed that I found a new-to-me invasive species in a new tub of bird seed: Indianmeal Moth larvae.

    Liked by 1 person

  7. Vinny, I’m with you on pheasant releases. I don’t see the point in shooting things for fun. Then again, I’m supposed to be an old-fashioned liberal, so I should not have anything to say about how other people spend their free time. Maybe they could be induced to eat the wretched things rather than ploughing the carcasses in as fertiliser?

    Also, we used to have these birds called partridges, which are now quite hard to find, apart from the French kind. Perhaps the mighty hunters could be induced to breed partridges (native ones) instead, and release those?

    It’s quite a coincidence that you should find Indian meal moths today. This afternoon, I found a swarm of booklice (species as yet unconfirmed) in a not-very-old bag of basmati rice.

    It does sound like rather a wildlife paradise in your back garden, if slightly diminished of late.

    Like

  8. PS. the story goes that pheasants associate cars with getting fed, hence have an unhealthy attraction to them.

    Like

  9. Jit – your thoughts on angling/sport fishing.

    PS – I opened a bag of flour to make bread recently & noticed little black critters in the flour. Eat them after baking.

    Liked by 1 person

  10. In modern Britain, the peasants are treated in much the same way as the pheasants nowadays.

    I’m not the pheasant plucker,

    I’m the pheasant plucker’s son,

    And I’m only plucking pheasants

    ‘Til the pheasant pluckers come.

    Try saying that quickly several times!

    Liked by 1 person

  11. This snippet from The Knowledge website may explain a lot:

    “ChatGPT is an avowed Guardian reader, says James Warrington in The Daily Telegraph. OpenAI signed a content licensing deal with the Guardian Media Group last year, and new research shows that its chatbot cites the newspaper in 58% of its responses – more than for any other news source. The next most-used news outlets are Reuters, The Independent and the FT.”

    Liked by 2 people

  12. Dougie, I admire your fortitude. My rice got the heave-ho. Plus, I’m a vegetarian, so no insect protein in my diet, unless the apocalypse comes, and I have no choice.

    As to the question of fishing – I am of the school of thought that believes that anglers tend to look after the places they go fishing. That makes them all right by me. I draw the line at catching sailfish, etc, though even that is a grey area, since if they have value for rich Americans to go fish for, then the locals might be more inclined to husband them.

    I have limited experience of fishing, but would happily sit on a river bank and watch wildlife for hours, without a rod. As a lad I was firmly put off fishing when a friend roped me in to join him in a sea-fishing competition on Pakefield beach (south of Lowestoft). I had his spare rod, bought some lugworms, and paid my fee. A late entry, I found my pitch was the last in the line, about a mile to the south, and far from my friend (in any case, the contestants were I think 100 yards apart).

    Well, I fished as hard as I could, and every time I tossed my worm in, back came the hook, empty of worm, and fish. I caught nothing all morning. Eventually my friend sauntered down the beach to tell me the contest was over, the prizes had been awarded, and everyone had packed up and gone.

    Yes, the ultimate humiliation was that no-one even bothered to wonder whether the tyro at the end might have caught something to put on the scales. Of course, they were right to judge me that way.

    My first, and last, angling competition.

    Liked by 1 person

  13. What’s the opposite of extinction? Expansion? Well, according to the Guardian earlier this week, the European Robin achieved a huge expansion of its range by appearing this winter in Montreal where it has attracted crowds of birders. A first record for Canada and only the fifth for North America. Possibly it escaped from a private collection or was blown from Iceland (to where it has expanded to). Of course being a story in the Guardian it had to suggest Climate Change, suggesting this may be responsible for track changes of North Atlantic storms.

    Poor little, cold, lonely Robin, hope it learns to speak Québécois quickly.

    Liked by 1 person

  14. Alan, this story was mentioned on R4’s PM yesterday, where a local ornithologist explained the bird was likely blown off course and landed on a freighter for a rest, ultimately disembarking at Montreal. On this occasion they did not find the need to mention climate change.

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  15. In fairness to Alan (welcome back, Alan, by the way), I believe the Guardian article about the robin did include a bit of climate change speculation. I would have been surprised if it didn’t.

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  16. Jit, it certainly is a bit of a wildlife paradise hereabouts. How many people can say they’ve had an otter in their garden?

    Or have a camtrap video of a squirrel jumping on the back of a tawny owl?

    But wildlife here has diminished. For example, there are no rabbits at all here these days – and I’m pretty sure that myxy isn’t the reason this time, as it bulgingly-eyed-and-slothfully-squatting was when they last disappeared. This time, it’s probably due to an increase in feral cats. Which cats have probably also had a large impact on local stoat and weasel populations.

    Mmmm, cats! Lovely critters!

    (They are. But please don’t let them go outside.)

    Liked by 2 people

  17. Vinny – I’m jealous. I do have something to look out for this summer – the local naturalist society’s transactions has a fulsome report on a nesting Xylocopa violacea elsewhere in the fine city of Norwich. I haven’t seen one since watching them nectar robbing in Crete. Quite amazing bees, “the size of Dorniers.” So, I’ll be growing some everlasting peas this year, just on the off chance.

    We have two 15-year-old cats, who are allowed outside. Only one casualty to report in their lifetimes: a zebra finch. I saw a glimpse of it at the window, and thought I was looking at a pale sparrow! (It was very lightly marked.) Then ten minutes later a cat brought it in, deceased. Probably completely tame – must have escaped from an aviary nearby. Poor little mite. Sad day.

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  18. Don’t mention cats to me, neighbours cats have killed little harvest mice in my garden over the years & not even for food, as the dead mice are just left.

    Liked by 1 person

  19. I used to have camera traps in the garden. Somewhere I’ve got several videos of a neighbour’s cat using injured mice as footballs. It swiped them into the air or along the ground then pounced on them as they tried to crawl away. Then another swipe and pounce. Then another. It made no attempt to kill them. (Its cruelty was probably due to the climate crisis.)

    Another neighbour’s cat used to leave dead shrews outside the front door. This was puzzling. I even wondered whether they were a form of payment for being allowed to use the garden but then I did some googling and found that shrews taste horrible. So the cat probably killed them in the back garden (which it visited every day), brought them to the front, had a quick nibble, then went ‘Yuk!’ and dumped them. (It probably kept killing them because the climate crisis had made it forget how horrible they taste.)

    In brighter shrew news, I once saw a shrew mum leading her young in a tail-mouth-tail-mouth-etc conga line just outside the front door. They were only a few feet away from me but didn’t panic. They kept in line until they found somewhere safe.

    (Good luck with the big black bee, Jit!)

    Liked by 2 people

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