A recent YouTube video from Kew came to my attention this week. All about our mistletoe, Viscum album, detailing its biology and growth and propagation, plus its biodiversity and some stuff on traditions and legends. All very very (almost suspiciously!) similar (even the title) to the words and phrasing I’ve used in talks and articles over the years. But generally a great video (did I mention it was familiar?). Even covering Viscum minimum on fleshy Euphorbias (another example I’ve often used). It feels like I’m being channelled but, to be fair, there’s only so much you can say in a brief intro and the points being made are the key ones.
One grumble though – and it’s a biggie (though maybe I’m just oversensitive to it!). The presenter, Neil Alderson, states that ‘over-harvesting of mistletoe is a possible threat to its population numbers’ and also that ‘the loss of traditional orchards has led to a decline of the species in some parts of Britain’. Both are untrue, just myths that seems to be widely believed in conservation circles, and have frustrated me for decades.
Mistletoe is not threatened by ‘over-harvesting’ nor has the loss of traditional orchards led to a decline of mistletoe anywhere. The misunderstandings arise, largely historically, from the premise of the 1990s mistletoe survey (which I initiated) that was run by the Botanical Society of Britain and Ireland (BSBI) and by Plantlife, the Wild Plant Charity. Our premise (put forward by me, so maybe this is all my fault) was that as apple orchards in the SW Midlands seemed to be (in popular perception) the primary habitat for mistletoe, and as those orchards are undoubtedly being lost, does that mean mistletoe is declining too? It was a question, which led to one of the most popular citizen science projects of its day – running for 6 winters or so through the 1990s. The project really caught the media’s attention, which loves a possible ecological disaster story, with accounts every winter, majoring on that question, in the press and TV all through the 1990s. The results were written up (by me) in 1999, in a report entitled Kissing Goodbye to Mistletoe? Note the question mark – many people seem unable to see it.
That report detailed what we found out. And that was that mistletoe was still most common to the south-west midlands area of England, where it has always had a stronghold (we were comparing to a similar 1970s BSBI study) and which suits it climatically. In that area, which also has a lot of apple orchards, it is common on a wide range of host species, well beyond apple trees. In that area it is also harvested, from apple orchards, at Christmas, just as it has been for a couple of hundred years now. Whilst there was some local loss in biomass of mistletoe, where orchards had been lost, the overall population was absolutely fine and thriving. There was no threat. It was not declining. Indeed, as later studies showed, in surviving but neglected orchards it was increasing, often massively (though only for a while if those orchards were subsequently lost, but still not a loss in the wider environment and other hosts).
Outside the south-west midlands the survey found mistletoe was much more common than previously thought, on a wide range of hosts, and had nothing to do with apple orchards. Furthermore there was evidence it was spreading further than it had before – i.e. outside its preferred geographic area. One angle that proved difficult to communicate – then and since – is that whilst orchards in the SW midlands have always been mistletoe strongholds the traditional orchards elsewhere never were. So, for example, mistletoe was never a big feature of orchards in Kent, though those Kentish orchards were, like elsewhere in Britain, also being lost. But it cannot be said that mistletoe scarcity in Kent is due to orchard decline, as mistletoe has always been scarce in Kent, and the current scarcity there has nothing to do with orchards. Never has been. Orchard loss, outside of the mistletoe stronghold in SW midlands, is not a primary factor for mistletoe. Never has been.
Basically the answer to the report title Kissing Goodbye to Mistletoe? was No, we are not kissing goodbye to mistletoe. Indeed, as the 1990s study showed, with more records than expected, and many other studies on a local level since, mistletoe is on the increase. With climate change, new bird vectors spreading it more etc, it is thriving and booming. Not going anywhere – except to grow more and in more areas. And traditional apple orchards, whilst a good habitat in the SW midlands, are not a primary need for mistletoe in that area or elsewhere.
But…. all that media attention in the 1990s, majoring on the doom’n’gloom idea that mistletoe was in decline, has been difficult to shift. The media want to believe it is in decline, and many conservation groups retain the idea that it is declining (as the concept was drummed into people every winter in the 1990s, and often since then too) but have not taken on board the fact that it isn’t. This hasn’t been helped by an additional angle, which is a true decline story, that ‘harvestable’ mistletoe may be on the decline, as fewer traditional orchards in the SW midlands, where the harvesting takes place, exist, so there is a threat to the harvest. But not to the overall mistletoe population. Which is fine, even without those orchards.
This confusion has reigned every Christmas now for some decades, with some groups, notably some Wildlife Trusts and even, a few years ago, the National Trust, sending out (actually irresponsible) press stories about mistletoe being threatened by orchard loss. It isn’t!! (though, as above, the mistletoe harvest might be).
I’ve often been on the receiving end of those stories – asked by the media to comment on a news story about mistletoe decline. And I’ve always tried, without actually rubbishing the NT/WT or whatever, to refine and clarify them, pointing out any threat is not to mistletoe, but just to harvestable mistletoe and that actually mistletoe is doing just fine. I’ve not always been successful in that refining though, especially if the story is based on a media release from a conservation body and that ‘official’ line is the peg the newspaper/TV/radio/whatever is hanging the story on.
The decline story is also peddled as a wider biodiversity loss story, especially regarding the dedicated mistletoe insects, all of which are considered rare, including the UK Priority Species, the Mistletoe Marble Moth. Those stories always highlight apple orchard loss as the main threat to those insects – but, in reality, those insects are probably doing fine in mistletoe that’s not in apple orchards. Where entomologists rarely look (as they tend to survey easily accessible mistletoe, in, er, apple orchards and in, er, the SW midlands), but where those insects may be just as frequent or even more frequent.
In my 2021 mistletoe paper in British & Irish Botany, the BSBI’s journal I tried to address all these misunderstandings once and for all, highlighting that the species is not threatened and that it is spreading faster now than previously. Even that struggled, with the first draft (not written by me) of the official BSBI Blog promoting the paper continuing to talk about mistletoe loss. At that point I realised that even writing it down didn’t work – but at least that draft blog was corrected. Subsequently our longer 2023 mistletoe paper in Journal of Ecology also highlights the absence of a threat and the reality of faster spread and increasing, not decreasing, mistletoe. But that’s a fairly technical paper and won’t have been read as widely as it might.
In conclusion I would say just this – that I wish I’d never agreed to that emotive title for that 1999 report Kissing Goodbye to Mistletoe? At the time it seemed clever and catchy. But the question mark is critical to understanding it. And many seem to ignore that question mark and see it as a statement. It is NOT a statement.
I would add, also, that that old Kissing Goodbye? Report is out of date, and shouldn’t be used to inform any mistletoe discussion now anyway. Better to actually use the up-to-date papers highlighted above than a 27 year-old popular summary. Those papers are here here (2021) and here (2023).
Here’s that video: