From the University of Exeter , some buggy science. Next thing you know, PETA will be campaigning to have us shut off street lighting to “save the insects”. I’m surprised it has taken them this long to figure out that bugs like street lights. Perhaps like moths drawn to a flame, these scientists were drawn to a grant to study this. The results are another “could may, might” effect on the entire food chain. Something MUST be done. /sarc
Street lighting is transforming communities of insects and other invertebrates, according to research by the University of Exeter. Published today (23 May 2012) in the journal Biology Letters, the study shows for the first time that the balance of different species living together is being radically altered as a result of light pollution in our towns and cities.
Believed to be increasing by six per cent a year globally, artificial lighting is already known to affect individual organisms, but this is the first time that its impact on whole communities has been investigated.
This study shows that groups of invertebrates living near to artificial lights include more predators and scavengers. This could be impacting on the survival rates of different species, having a knock-on effect on birds and mammals that rely on these species for food. The effects could be affecting entire ecosystems and even humans.
The research team based their study in the market town of Helston in West Cornwall. They placed pitfall traps directly under and between street lamps that were 35 metres apart for a number of days and nights. This allowed them to compare, not only results for day and night, but also differences between areas under and away from street lights.
They collected 1,194 individuals covering 60 species. They discovered that total numbers were more abundant under street lights, where they also found more predatory and scavenging species, such as ground beetles and harvestmen. This was the case during the day, as well as at night, suggesting that the effect on communities is ongoing.
Lead author Dr Tom Davies of the Environment and Sustainability Institute at the University of Exeter’s Cornwall Campus said: “Our study shows that light pollution could be having a dramatic effect on wildlife in our towns and cities. We need to be aware of how the increase in artificial lighting is impacting on the delicate ecosystems on which we all rely. Our research shows, for the first time, the changes that light pollution is making to entire communities of invertebrates. We now need to examine what impact this is having on other communities and how this may be affecting important ecosystem services and whether we should change the way we light urban spaces.”
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Words probably fail you often when you don’t understand them. “They placed pitfall traps directly under and between street lamps that were 35 metres apart for a number of days and nights. This allowed them to compare, not only results for day and night, but also differences between areas under and away from street lights.”
SocialBlunder says:
May 23, 2012 at 8:14 pm
“Words probably fail you often when you don’t understand them. “They placed pitfall traps directly under and between street lamps that were 35 metres apart for a number of days and nights. This allowed them to compare, not only results for day and night, but also differences between areas under and away from street lights.””
No it does not. Focus on the science, not the words.
They needed to do control experiments that allowed them to eliminate factors other than light.
Consider: If birds ever perch on the street light and defecate, then it may affect the ground underneath which, in turn, could easily affect the vegetation and insects. A location distal to the street lamp will be affected by more factors than just light.
Some other confounding factors for these authors to consider:
1) Dogs also like to urinate against lamp posts, especially male dogs.
2) Female dogs often have a different style, and hormones in their urine can have a pronounced negative effect on plant growth and hence insects.
3) Some insects, such as ants, may make a nest under the lamp post.
4) Spiders may weave webs on the post.
5) I also find in difficult to cut the grass directly next to a post in the ground.
6) It may also be warmer right next a an object that is consuming electricity.
7) Some lamp posts make an electrical humming noise. I walked past one last night. Perhaps insects are affected by that.
8) Were the posts made of metal or wood?
I certainly don’t think that article is worth reading any more.
iF THE AMOUNT OF BUGS AROUND THE LAMPS WAS GREATER THAN IN BETWEEN FOR BOTH DAY AND NIGHT, MAYBE IT IS THE POST THAT ATTRACTS THEM AND NOT THE LIGHT ON TOP. MAKES A MUCH SENSE AS ANYTHING ELSE IN THIS.
[Please check your caps-unlock key…8<) Robt]
Aha… let’s all go quietly into the dark, for cockroaches’ sake.
i used to observe birds feasting under the streetlights at night…day birds adapting to a new source of food
Light pollution? not just light? what’s the difference. I guess we should just do away with humanity and that includes mad scientists. No people means no lights means the bug populations will grow to their level of sustainability to be eaten mercilessly by bigger bugs. What a perfect world. Ultimately humans may re-evolve and start the cycle of producing too much light again
Darwin makes common sense to me. Evolution of species, survival of the fittest, seek the best mate.
If I was a lonely, lustful male insect late at night when the pub lights had gone out, I’d welcome the light from a street lamp to be sure I was moving in to mate with a luscious female. Oh, quel horreur if I got it wrong through lack of light pollution.
Speculation about what might, or might not, be going on in an urban area are irrelevant in the context of this “survey”. The paper says “.. in the town of Helston, Cornwall, UK (50°06′ 09.06” N, 5°15′ 29.83” W), which is not IN the town (a mere 9,800 pop. town at that) but on the eastern grass verge of the A394 bypass to the E of the town, with agricultural fields and woods immediately adjacent to the east.
http://maps.google.co.uk/maps?q=50.102516,-5.258286&hl=en&ll=50.102744,-5.258439&spn=0.007226,0.011802&sll=51.628611,-0.748229&sspn=0.111887,0.188828&t=h&z=16
Re: PETA
You might like to know that, a year or so back, when there was a gas rig doing exploration work on the shores of Lake Geneva, the local Khmer Verte tried to get it shut down because its lights were attracting too many bugs from the nearby national park.
There is no parody you can attempt of the behaviour of these loons that surpasses their actual inanity!
That’s a great photo. 🙂 I’ll have to try to get one like that.
I wonder where all those bugs are going to go when they switch off the lights?
Oh, I forgot, streetlights are usually hard wired, so the whole grid will have to be taken down.
So, the bugs simply have to wait a bit until the contents of refrigerators are emptied.
It’s much worse than previously imagined.
Greg says:
May 23, 2012 at 5:02 am
Do these researchers ever take a drive out to the country?
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There is a part of the country left that isn’t overwhelmed with light pollution? I live in a very small, under 3,000 people, town, and there is a street light about every 100 feet, if even that far apart. At night, if you are lucky, you might see 5 stars in the sky. Most of the time you can only see the moon. Light does affect wildlife. It’s basic junior high school level biology. I know some would like to see every square inch of the planet lit up like Las Vegas, but it’s not good and it’s not healthy.
The obvious solution is more government, just like everything else.
I’m waiting for the appropriate three different federal agencies working on the same solution to the same non-problem to issue grants to the various state governments so the states can each use two different deaprtments working at cross-purposes to issue funds to the counties so they can distribute the money to their cities and towns to buy all those little night bugs teensy-eensy-tee-tiny-itty-bitty nano-SUNGLASSES, regardless of any individual bugs’ ability to pay. We can pay for it by taxing the rich.
There. Problem solved. Let’s move on.
Michael Hart makes some excellent points, but other than the poor experimental design (one town, 3 days and nights [one for each author?] in one August, 14 street lamps, two pitfall traps per lamp at set distances, no real controls, and arthropods lumped into artificial trophic categories), the major problem with this study is that pitfall traps (cups dug into the ground into which wandering animals may fall and drown) measure activity levels, not abundance. The more you move, the more you are likely to fall into a cup.
So, perhaps ‘predators’ were more active under those 14 street lamps at night (this is nothing new) on those three nights in August in that town. If you look at the differences in their tables (mostly very small and with overlapping standard error bars) though, with that many comparisons something was likely to be significantly different by chance, and they didn’t transform the data (highly unlikely to be normally distributed) for the ANOVA (and one wonders why not?).
Good example of how waving a bloody shirt can make or break a paper. But these people are ecologists, not entomologists, so Anthony’s headline is unfair to real buggos.