This is an account of an article from the Newsletter of the British Horse Society. It appeared in the March April 2001 edition of their newsletter. It illustrates the false awareness they were raising just a few years after they started working on ragwort. It is an atrocious example of how they have misled their own members.
The first thing to remember is that since World War II there has been a massive rise in agricultural intensification. This means that nearly ALL of our wildflowers have declined. So has the wildlife associated with them. (Studies have found the overall number of moths has decreased by 28% since 1968. The situation is particularly bad in southern Britain, where moth numbers are down by 40%.). So to claim that ragwort is somehow massively increasing is irrational because years ago it used to be more common. This is the first of the quotes from the article.
The reasons for the increase are by no means clear , but there are several possible explanations The explosion of ragwort in the 90s coincided with the financial pressures on local authorities that came about with the restraints of the Standard Spending Assessment and the introduction of 'capping" of council spending introduced by the government of the day. One way of saving money was to stop the regular mowing of roadside verges.
Ragwort actually needs bare ground to germinate so any move to make verges less open and more densely packed would actually work against increasing it.
The ragwort was then allowed to flower and quickly spread by seeding. At about the same time, there was a[sic] ecological move away from wholesale spraying A corresponding growth in road building disturbed soil and allowed dormant seeds to germinate, and the bare ground was a willing host to passing seeds. Another possible explanation is the diminishing of the butterfly population, perhaps resulting from intensive farming practices. The cinnabar moth, which feeds exclusively on ragwort and groundsel, was one of the casualties. Forty years ago the striking red[sic] and black caterpillars [ The adult moth is red and black. the caterpillars are yellow and black] were a common sight, but they are rarely seen nowadays. The extreme conservationists have accused us of trying to destroy the natural habitat of this lovely moth. The truth is that there is more than enough ragwort around for the caterpillars to feed on. let alone the abundance of groundsel.
This is complete and utter nonsense! It betrays a complete lack of knowledge of ecology. It is necessary to state at this point that the concern of conservationists is not primarily the cinnabar moth but all the other wildlife that needs ragwort. It is one of the most valuable nectar sources and supports a wealth of invertebrates, but let us just consider the moth (and it is a moth, not a butterfly).
It is true that the cinnabar moth has declined but the prime reason is like all the other declining wildlife that habitat has been lost. Those flower rich pastures and the ragwort plants have declined massively since World War II.
The idea that groundsel can support the moth's populations is both botanically and ecologically ignorant. The plant is what is known as ruderal. It grows on disturbed and waste ground and it does not persist for long. It is also very very much smaller than ragwort and normally grows no more than a few inches high. Cinnabar moths lay their eggs in batches. A single groundsel plant might not even be able to support the growth of a single caterpillar where as a much much larger ragwort plant could support many.
There is a research paper that was published in the journal Entomologia Experimentalis et Applicata. [2] It studied the effects of three plants on the cinnabar moth. These were ragwort (S. jacobaea) groundsel (S. vulgaris) and coltsfoot (T. farfara) Here are the relevant results:-
Larval batches reared on S. jacobaea had significantly lower mortality (<1%) than those on either S. vulgaris (approx. 4%) or T. farfara (approx. 15%, which was also significantly greater than S. vulgaris)
So the caterpillars do better on ragwort. The paper goes on to talk about the egg laying preference of the adult moths.
Adults showed the same hierarchy of preference as the larvae, however they never oviposited on T. farfara.
The data from all the available research put together is very clear. The moth is obviously specialised to feed on the larger ragwort plants. It cannot survive on groundsel alone.
Then there is clear lack of knowledge demonstrated by suggesting that the campaign has not affected the moth because there is plenty of ragwort elsewhere. From the viewpoint of anyone who has studied ecology and the population dynamics of insects it is a fundamentally wrong statement.
We know that wildlife in general has declined because of massive habitat loss and there is a fundamental part of the science that governs this that applies to the moth. The habitat of the moth doesn't persist over long periods. Ragwort will disappear from places and appear in others over a period of time So the moth has to periodically disperse to find new sites to live on. The problem here is that if it doesn't find a new site then that population becomes extinct . As its habitat is reduced, more and more of these dynamic, moving, populations groups is disrupted and destroyed.
The really important thing here is that this doesn't just apply to the moth but to any wildlife which is reliant on the plant and remember there ecological needs of species may not just be the presence of the plant. For example ,the density of the population of specialist predators or parasites may be controlled by other environmental factors and therefore not all sites may be suitable. This would further endanger the survival of populations. The basic point here is that the science of the ecology of populations shows that habitat destruction frequently leads to a larger percentage of wildlife loss than would be calculated if wildlife loss were simply proportional to the loss of habitat.
This is a technical term for all of this science, "Metapopulation Dynamics". Scientists love complicated language and a metapopulation is defined as "a collection of local populations, connected by occasional dispersal, in which there are local extinctions and colonisation." Articles on ragwort and the wildlife associated with it appear in several of the technical textbooks on this subject.
Next we have several statements in one paragraph which are wrong.
Part 1
While the widespread use of herbicides and artificial fertilisers may be responsible or the lack of cinnabar moths, the introduction of SSI =Sites of Scientific Interest[sic]- with aims to conserve our windflower heritage,This statement really displays the ignorance of the author of the BHS article. The lack of knowledge of the terminology seems to demonstrate a complete unfamiliarity with the subject. It isn't SSI it is SSSI which, as anyone familiar with conservation will know can be pronounced ES ES ES I or Triple ES I Anyone at all used to speaking about conservation would know it has three S components. It is Site of Special Scientific Interest. Aside from this howler, it also completely misunderstands the nature of these sites. They weren't created, they were designated as named sites because of their EXISTING flora and fauna. Any ragwort would have been present or absent before this designation.
And part 2
and Set Aside are other possible reasons for the explosion of he dreaded weed. Once ragwort is allowed to flower it will flourish with a vengeance.Actually Professor Crawley who has studied ragwort over many years tells us that the best way to control ragwort is to actually manage the sites where it grows appropriately and let it flower! See Ragwort Control
And part 3
There is no evidence offered at all in the article to show that it was on the increase only a lot of surmising and guessing, in a most ignorant manner. The evidence that we do have shows most clearly that the plant was actually not increasing during this period. So the statement that they knew it was increasing was obviously false because they couldn't know it without evidence and the evidence that does exist shows it was false.Added to all this over the past few year we have had a succession of mild winters and warm wet springs, ideal condition for germination and growth. All- or possible none - of these explanations for the proliferation are plausible, but the truth is that we cannot be certain of any of them. What we do know is that it is on the increase.
The article continues with this amazingly naive confession that they didn't know what they were on about. Bear in mind that by 2001 the BHS had been campaigning to vilify ragwort for several years.
To begin with it was difficult to get the media interested. Their first question was always ' how many horses die of ragwort poisoning every year?' The answer of course was we don't know. We couldn't even come up with an owner whose horse had died of ragwort poisonings- The necessary 'case study' that is so vital for any media story.
It seems they were running a campaign, promoting an idea without knowing the essential fact of whether their campaign was correct or not!!
This question is, incidentally, impossible to answer as there is no definitive test for ragwort poisoning. See Ragwort there is no test which can confirm it 100%
Notwithstanding this, there is abundant evidence as documented elsewhere on this site that the figures that were later arrived at by the BHS and their associates were false as they were obtained by means which are clearly unscientific, statistically invalid and plainly unsustainable.
Later on in the article there is this section which is entirely based on a false premise. There is no test that can confirm ragwort poisoning.
TESTING FOR RAGWORT POISONING,The only certain way to be sure that a horse is suffering from ragwort poisoning is to do a biopsy. However is is theoretically possible to detect the alkaloid in the blood at very minutes concentrations. There are blood tests that will show the presence of enzymes which newly damaged hepatoocytes [sic] leak into the blood stream. Dr Derek Knottenbelt and his colleagues at Liverpool university are seeking sponsorship for a preliminary trial. A random testing programme would give us an idea of the number of equines that are affected, and therefore a true picture of the extent of the problem.
This test never really worked. A student was given the research task for her PhD. Ninety one horses that had signs of liver damage were tested. Only one , an abuse case, showed a positive result.[1] The following section indicates what the British Horse Society was promoting as a likely result. That a large proportion of horses who didn't even have signs of liver damage were being poisoned, when there was no evidence that it was the case.
If we could prove that say 10% of horses and ponies have been affected by ragwort poisoning then the campaign could shift into a higher gear, and a more effective eradication programme would follow. The proposed trial will require owners and vets to agree to take part in the testing programme.
WHERE DO WE GO FROM HERE?
In order to reduce the incidence of ragwort and prevent a further spread, two things are necessary; One is to prove that there really is a problem: that horses , ponies and donkeys are in fact dying as a result of eating ragwort. At the moment we can only document a few cases a year - not enough to warrant the spending of hundreds of thousands of pounds of public money on what might be regarded as a few pets. We must persuade vets and owners to the need to test for ragwort poisoning - and report the result to the BHS so that we can get an accurate picture of the extent of the problem. Only then will our concern be validated. Dr Knottenbelt's research will prove invaluable in this.
This is actually a stunning admission, The BHS has never produced any substantive evidence that "there really is a problem". They were already campaigning, without evidence and had been for several years. Any further supposed evidence they produced was either established by using misleading with false statistical methods, falsely claiming they had established examples of poisoning when there is no reliable test, or along the lines of we've done a lot of surveys and we've found horses growing in fields with ragwort, we haven't got poisoning examples, but our members are really worried about it. Of course the members were worried. They were being panicked by misleading articles like this one.
References
1 Moore, R.E , 2008 . Novel Strategies for the Detection of Ragwort Poisoning in Horses PhD thesis University of Liverpool.
2 Tinney, G. W., Hatcher, P. E., Ayres, P. G., Paul, N. D., & Whittaker, J. B. (1998). Inter- and intra- species differences in plants as hosts to Tyria jacobaeae. Entomologia Experimentalis et Applicata, 88(2), 137-145.
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