Sunday, 9 July 2023

The Canary, the Butterfly and the Licence Plate - The decline of insects

 I have spent just under half my life visiting and recording wildlife on my patch, that’s quite a chunk of my time, about 20 years to be truthful. I am someone who likes routine, but this is more than that. This is a piece of land that I love and am in sync with. I have seen enough now to be in tune with some of nature’s cycles and realise when something is off. Some people may get bored with visiting just one spot, in fact, many birders or twitchers chase the dream birds, would I do that if I enjoyed traveling… I think not. There is something special about becoming part of an ecosystem and understanding its ebbs and flows.  Besides the site continues to amaze and surprise me.

Marbled White

Just today I was out for my normal Sunday morning visit having lamented the previous week’s lack of butterflies. Last year the farmer cut the meadow and I had predicted to myself that the loss of many of the nettle beds and more grass would result in fewer tortoiseshells but more ringlets, meadow browns, skippers, and gatekeepers. So far, this vision had not been borne out. I was beginning to think about the national insect decline. This is a national crisis affecting all of Britain. Invertebrates are an essential pillar in our habitats. They provide the bulk of the food for our nesting birds and breeding fish which in turn provide for our predators. How can we expect our declining Swifts to survive if not only are we robbing them of their nesting spaces but their very food?

To highlight this problem, I had a mini epiphany this week. It is early July and Wimbledon is in full swing. When I was a child in the late 1980s my sister and I would watch some of the matches but more often we had more fun playing our own Wimbledon in the back garden. Mum would string some wool across the garden to act as a net and we would come out on to centre court with our plastic blue rackets and our bright yellow or red sponge balls to play a few games, complete with MacEnroe-style debates regarding what was in or out and who was serious.

One of the key features of these games were the clouds of midges that seemed to hang in the air at the bottom of the garden. These were not the Scottish midges that would eat you alive but more the tiny non-descript tiny flies that as a species seemed to serve no purpose except to annoy. We would take great delight in swiping our rackets at them, imagining we were decimating their numbers like mighty warriors when in fact I doubt we ever struck one, so large were the holes in our rackets and the air pressure created. The point is that when I look at the bottom of the garden now, I find it hard to see a single simple fly. We have insects, bees, wasps other flies but in much smaller numbers. We have never used insecticides and our garden is wildlife-friendly with overgrown patches and an adequate pond so it’s not a change in the very local habitat but something wider, something national, something global.

Buglife has been assessing this problem and has just (June) released its 2023 Bugsplat survey. This innovative survey assesses the number of insects that get squashed on a number plate across a certain distance driven. This is of course a citizen science project and as such have inherent flaws in the distribution of responses. Scientifically comparing long-term trends, I wonder whether there is an effect on the change in car design and aerodynamics that might affect the data, but that’s just my analytical scientific brain working overtime. The survey now, digitized via an app, aren’t they all these days, demonstrates that the number of insects sampled on a licence plate between 2004 and 2022 is down 64%. This value backs up the more anecdotal evidence and something that for me is an observation.

Luckily my patch continues to surprise me. With most of July and August still to go it is hard for me to assess if butterfly numbers are down on my patch, but today’s survey was encouraging. The survey was done this morning following a night of rain with increasing sunshine and a light breeze, within the hour I had seen 6 Ringlets, 3 Meadow Browns, 2 Red Admirals, 3 Commas, 1 Large Skipper, 31 Large Whites, and 1 Marbled White. The Marbled White is particularly exciting. This has never been recorded at the Saxon Mill before, in fact, I have only seen this species out towards Charlecote and Stratford way in the past until this year, when I recorded one last week at Warwick Racecourse.

So what is the moral of the story, two things, I do not think I will ever get bored of my patch, it continually surprises and after 20 years I am still discovering new species, secondly, insects are suffering and insects are not the only canary in the coal mine that has become choked on the gases produced in the past few years.