The Guardian seems to have decided that climate change is the most significant problem for insect life, despite its own articles suggesting that other factors represent much greater problems. I observed in a comment on “What’s The Buzz”i that the headline to a Guardian articleii recently warned us that “Climate crisis could lead to rise of smaller bees” despite the article itself saying that:
One in six species of bees have gone regionally extinct somewhere in the world.
The main drivers of extinction are thought to be habitat loss and pesticide use.
Discussion followed from my comment, with JIT pointing out (I paraphrase) that the bald claim in the headline was overly simplistic. Important though his intervention was, I am perplexed at the determination of some to push the climate agenda in the face of much bigger issues. Climate change may or may not be a problem for insects such as bees. But if one-sixth of bee species are known to have become regionally extinct due to habitat loss and pesticide use, that’s a real problem, and it should concern us. Why do we not have anguished Guardian headlines about that?
Similarly, in “Glow-Worm Waning”iii I drew attention to a Guardian articleiv which sought to blame climate change for a collapse in UK glow-worm numbers. I established, to my own satisfaction at least, that the claim was over-done, and that many other factors are behind the decline. Indeed, I found that the Guardian itself wrote that:
Habitat loss, light pollution, and pesticide use were regarded as the most serious threats [to firefly population and species persistence].
And yet, as always, it’s climate change that carries the can.
Moths declining faster in British woods than farmland or cities
When I read the above headline to yet another Guardian articlev about the problems of insect life I was fairly confident that a climate change angle would be introduced, regardless of the reality that would be revealed by reading the entire article. The sub-heading tells us that “Insect’s forest populations have halved over past half-century despite increased woodland habitat”, which is intriguing, to say the least. And so I read on. And this is what I found:
Moths are a well-studied indicator of wider insect declines that recent research has often linked to presticide [sic] use by industrial farming, habitat loss and urban light pollution – none of which directly affect woodlands.
So far, so good. A clear acknowledgement that insect declines have been linked to pesticide use, habitat loss and urban light pollution, as we saw above in connection with glow-worms. But:
Moths have declined faster in British woods over the last half-century than on farmland or in cities, despite woodlands having increased and moths being shielded from chemical and light pollution by the trees.
Well, that’s a mystery. Woodlands have increased, moths are thus shielded in these areas from chemical and light pollution, and yet their numbers are down in these areas by a greater amount than in those areas where they lack such protection from those destructive problems. What gives? Climate change, of course!
The loss of moths from woodland could be partly because of climate change…
Those last words form an embedded link to the Guardian article at endnote iv here, so that’s hardly conclusive. In fairness, the sentence I cut short above went on to offer other possible explanations, but then dismissed them for what seem like sound reasons:
…or less woodland management such as coppicing, leading to more shading or increased deer density causing more intensive grazing. However, the team of scientists found moths whose caterpillars fed on shade-intolerant plants or shrubs and woodland flowers grazed by deer did not decline any more than species relying on unaffected grasses, trees and lichens.
So, it’s a mystery. I decided to look at the papervi on which the Guardian article was based, and I think this is probably the critical paragraph:
Finally, climate change is known to have contributed to the national decline in moths (Martay et al., 2017) and it is likely that this has driven at least part of the decline observed in woodlands. However, this cannot explain why the declines have been worse in broadleaf woodland compared to other habitats. Indeed, we might expect the shade provided by woodlands to help buffer against the effects of climate change (De Frenne et al.,2013). However, the interaction between climate, habitat and moth abundance trends remains to be tested.
And the final point in the abstract makes it clear that no definite cause has been identified:
…the primary cause of the decline of moths in woodlands remains unclear.
In fairness, the Guardian headline didn’t blame climate change, but part of the article did, even though the two penultimate paragraphs did posit possible alternative explanations:
…other possible causes of woodland moth decline could include the spread of invasive shrubs such as rhododendron or laurel and habitat fragmentation, with woodland moths still affected by agricultural intensification beyond the woods.
He said: “Although the amount of woodland in the UK hasn’t declined since the 1960s there might be more fragmentation due to the loss of hedgerows and trees outside woodlands so that could be something for future studies to look at.”
Climate change to blame, or not? Who knows? The situation seems to be as clear as mud, but in the absence of any sure knowledge, what the hell? Let’s give it a substantial mention.
Swallows and martins head back to the UK but a changing climate threatens their future
It’s not just insects, of course. According to the Guardian articlevii bearing the above headline, it’s also swallows and martins. And yet, given that the Guardian has been telling us for agesviii that spring is arriving earlier and earlier in the UK (and that this is causing wildlife all sorts of problems), something about the headline and the sub-heading (“Migrating birds were delayed by poor weather on their 6,000-mile journey from southern Africa, shortening their breeding season”)failed to make much sense to me. Surely that poor weather was because spring arrived later in crucial parts of the northern hemisphere? And indeed, that is exactly what the Guardian reports:
But this spring, the swallows didn’t arrive back at the workshop until 10 April – the latest they have ever returned in nearly 40 years. Numbers are down, too. At the turn of the millennium, at least 20 pairs nested here; nowadays, there are just five.
Swallows were late back to my village, too. In the 16 springs we have lived here, the average return date has been 8 April – but this year I didn’t see one over my garden until the 25th. How different from that gloriously fine lockdown spring of 2020, when the first swallow appeared a full three weeks earlier than this year.
At Portland Bird Observatory in Dorset, where many of our swallows make their first landfall in the UK, Martin Cade, a warden, confirms that this has been a very slow year for spring migrants. “The first half of April was rubbish,” he tells me. “There were virtually no birds – and a lot of very grumpy birders.” Some may have been passing overhead thanks to fine weather, but nevertheless numbers of birds were far lower than usual.
Cade estimates that, this year, the main arrival of migrants has been roughly 10 days later than usual, peaking in late April, rather than the middle of the month. The latest nationwide figures from BirdTrack, organised by the British Trust for Ornithology, confirm this, showing that swallows, sand martins and house martins are all arriving between one and two weeks later than expected this spring.
In the Scottish Highlands, house martins usually arrive by mid-April, with swallows a week or so afterwards. But the conservationist and nature writer Sir John Lister-Kaye tells me that, this spring, neither have yet returned to their breeding sites
There are two reasons for the lateness of the swallows and martins. Unlike many other migrants, which fatten themselves up before they depart, these species feed as they travel, replenishing lost energy by catching flying insects. For that reason, they are especially vulnerable to bad weather en route. And the weather in southern Europe this spring – notably in southern Spain, which these birds cross after leaving Africa – has been very unsettled, with heavy rainfall, strong winds and even falls of snow across parts of Andalucía.
The second reason is that, here in Britain, although the weather has been mainly dry, there have been persistent easterly and north-easterly winds, which also slow down the birds’ progress as they head north.
Checking my notes, I see that I spotted house martins while on holiday in Glencoe on 12th April 2010. If they’ve just arrived in Scotland at the very end of April 2022, then that seems to be rather inconvenient in terms of the ongoing narrative that spring is arriving earlier, thanks to climate change, and that it’s causing chaos for bird-life. Now we find it arriving later this year (as it did last year too) and I suppose we have to wonder if that’s due to climate change too? Or is it just weather?
Don’t be silly. Whatever happens, it’s climate change:
Yet I am concerned that rapid changes in the world’s climate – including more frequent and extreme weather events – pose a real threat to these birds’ long-term future. Disturbingly, this year some swallows even attempted to overwinter in Cornwall, suggesting that the climate crisis is already having a major impact on their behaviour.
In some quarters there seems to be a quasi-religious belief that however strong the evidence for non-climate-related explanations for the decline of any particular species, it can safely be set aside or its significance minimised and all ills blamed on climate change. All I can do is keep testing and analysing the strength of the evidence, and share my findings here.
via Climate Scepticism
May 1, 2022 at 06:19AM