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Jono mentioned, in the Challenge forum, that it's insect week in the UK.
There are far fewer insects nowadays than there used to be.
I remember all the splats on our windscreens, now there are hardly any.
Is it because more pesticides are being used, or is it something else?
Rik, mostly something else. Car design extensively uses computers to reduce airflow resistance and improve performance. The bugs are being pushed out of the way. Just drive with your head out the side window with your mouth open. A beautiful example of an uncontrolled trial being used as 'proof' is here: https://www.nhm.ac.uk/discover/news/...-20-years.html.Quote:
Originally Posted by Rik
There are fewer leafy avenues as roads have straightened and widened. A far better study does present a general decline with variation for a range of factors. Only one of over 300 references mentions driving and that is for the US.
Acorn
:-OQuote:
just drive with your head out the side window with your mouth open
I'm not sure if the trial is 'proof' but I'm sure it provides some indication of decline, together with evidence from other more scientific studies.Quote:
Originally Posted by Acorn
I don't think the survey is attributing the decline of insects due to being hit by cars, but rather as a way of recording and comparing the number of flying insects squashed over a measured distance.
For info Buglife - the only organisation in Europe devoted to the conservation of all invertebrates, (yes, I am a subscriber :D) are currently running the survey again right now.
https://www.buglife.org.uk/get-invol...s/bugs-matter/
Jono, what I get cross over is such studies can not be scientific. Yes, the car number plate or windscreen count is an indicator but it can not be normalised: weather, time of day, season, decade, speed, car design, driver emotion, urbanisation, route, volume of traffic, farming practices, ...
A better tool might be the number of swifts around. They are purported to eat 10,000 flying insects a day. Have they declined? Do they look thinner?
Swallows are more economical at 60/h. House martins are more omnivorous.
Predators come and go as do prey, roughly following predator-prey models. Models similar to coronavirus models and we saw how robust these were.
Locally, we have hordes of damsel flies, extremely voracious hunters. Next field, it's all Marbled White Butterflies.
We have too many microbiomes to 'number plate' sample to form conclusions.
Acorn
Yeah, I'm not a huge fan of 'citizen science', which is what the 'bugs matter' insect survey is, but at least it's doing something and it's quite good fun recording the number of bugs you've squashed on the way to work. I think it's when you look at the results over a number of years, that population pattens and trends can be evaluated.
You're right, there are loads variables making it difficult to normalise the data. But at least it gets a few people thinking about insects and feeling they are involved and contributing in some way.
As I'm sure you know, swifts (Apus apus) are on the RSPB's 'Red' list - birds that are in critical decline, and of course, swifts (and swallows) are migratory birds making collecting their data even more difficult. There's a swift mapping survey currently running on the RSPB website! ;)
It sounds like you live in a high biodiverse part of the country. The marble white is one of my favs and I can watch damsels all day. Enjoy them while you can!
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Egg, that's great and explains it. ;))
Interestingly I read somewhere, that wasps are getting smaller due to climate change - less impact damage! ;)
I love wasps - they eat aphids and all sorts of garden pests that I don't like; maybe they are also suffering from a food supply depletion...
My number plate bug reporting is going quite well, although not many actual bugs so far!
Attachment 133788
I've mostly only been doing fairly short journeys so far (about 10 miles, 16km) and apart from one day where I counted 8, the average seems to be about 1 or 2 splats, and that's even after going through countryside where I thought the numbers would be much higher.
For anyone interested, in post #4 above, the linked page contains another link to the Bugs Matter 2022 Full Technical Report (PDF, 84 MB) that details how they analyse and make use of the statistical data.:eek:
Poor Bambi!Quote:
Originally Posted by Jonopen
Jono, I'll also have a read.
In reading, there are so many assumptions...
Acorn
That's the problem with statistics. I don't know if the report has been peer reviewed or what the scientific entomological community make of it. It is well researched, referenced and had a wide reading though.
In the absence of any primary data showing that insect populations are stable or increasing, I personally would like to think (assume!) it has some relevance and over time will give a some indication to how things are going. Any analysis that uses a zero-inflated negative binomial generalised linear model, gets my vote! ;)
If I knew what that meant I'd agree 100% Jono :confused:Quote:
Any analysis that uses a zero-inflated negative binomial generalised linear model, gets my vote! ;)
I don't understand the full nitty-gritty but there's a fairly high-level explanation on page 8 if you're really interested! :DQuote:
Originally Posted by Egg Bramhill
The following is a small extract:
"We used a zero-inflated negative binomial statistical model to examine the relative effects of survey year, time of day of the journey, calendar date of the journey, average journey temperature, average journey speed, journey distance, vehicle type, local NDVI*, and road type, on the splat count**."
* Normalised Difference Vegetation Index
** The number of insects impacted on the number plate