podcast recording

The podcast discusses the negative impacts of artificial light on invertebrates and their populations. It explains that 23% of the planet's land surface experiences elevated levels of light at night, which can disrupt the behavior of insects like moths and glowworms. This light pollution affects not only creepy crawlies but also pollinators and other animals that rely on insects. The use of electric lights and the lack of proper shading contribute to this problem. The podcast suggests that individuals can help by turning off unnecessary lights and advocating for regulations that promote insect-friendly spaces. Hello listeners, and welcome to Creepy Crawly Conservation. My name's Kai, and I am joined today by Sammy. Hi, Sammy. I'm good, thank you. Our topic this week is all about light, specifically the artificial kind, and how it can harm invertebrates and have negative impacts on their populations. God, yeah. Constantly. Always yelling into his phone at the office, disrupting every- Oh, yeah, that makes more sense. The acronym scientists use to talk about light pollution? Even those teeny tiny green lights on the bottom of fire escape signs? Did you know, I found this out recently and it just blew my mind, 23% of the land surface of the planet experiences artificially elevated levels of light at night. For context, only about 12% of the planet's surface is used for agriculture. Is that because bugs are attracted to bright lights? Oh, so if a moth is trying to tell where it is by making sure it keeps the moon on its right-hand side, for example, then if there's a brighter light, it'll end up just flying around and around and around it. Like with the glowworm, I love those little guys. So more lights means fewer glowworms because potential mates can't find each other, settle down and start a family? That sucks. Oh yeah, I remember the streetlamp at the bottom of our street when I was a kid was a prime spot to see bats because they would just be flying in and snacking non-stop. This sounds like bad news, and not just for the creepy crawlies, but for all of us. I mean, aren't these little critters kind of important? They're our pollinators and they form the foundations of many food webs. So if we lose our insects, we lose a bunch of other animals. But as previously discussed, these insects are often pollinators, so our plants are suffering too. Okay, so this is a serious business, but do we know how it all started? I feel like humans have been lighting fires for a while. Why has this only just become an issue? Yeah, okay, electrical lighting. Much brighter than a bonfire. And along with making far more effective insect traps, these electric lights have spread to everywhere because they're just so damn useful. I mean, I live in a city and anywhere in the park near my flat, I'm no more than perhaps 10 metres away from a streetlamp. Yeah, when you really start thinking about it, it is everywhere. Like obviously in population centres, but even between them. Roads of streetlamps and car headlights. And you can usually see other lights from far away, which I guess still counts as light pollution? Right, right, okay, so basically no light is correctly shaded and every light we use is causing light pollution. So this is a serious issue and one which, judging by the number of shops and office buildings I see leaving lights on pointlessly overnight, one which people are doing very little to address. But there have been some papers, or else we wouldn't be here talking about it. In a recent study by Owens in 2020, researchers have pointed towards so-called diurnal bias as a potential cause of this conservationist blind spot. As it's easier and generally more pleasant to work during the day, Alan is inherently more trouble to study than other insect issues like pesticides or habitat loss. Is this where our little conversation on phototaxis comes in? Don't mind me, just using the fancy lingo for being attracted to light there. But even beyond phototaxis, dragonflies and wasps maintain a horizontal position in the air by identifying which half of their visual field is lighter, and as a result of light upwelling from the usually dark half of their visual field, they literally don't know which way is up. Wait a minute, insects migrate? I never even thought about that. And with all of those lights in the way, I guess this messes with their ability to work out where they are? And this fragmented habitat just makes all movement more costly and less efficient, I guess. If you have to take a long route to get from one meal to another, you're just wasting energy. Moths really get a rough deal. I saw that in some species, increased light causes physiological changes. It suppresses the female sex pheromones and literally sterilizes the males. Could you briefly explain that for me? So it's not just Alan causing issues, it's even the materials we use. I imagine this could really screw with aquatic insects. And the skyglow of artificial light is affecting the natural pattern of polarised light in the atmosphere which we can't even see. Remember those polarised lights? This all sounds very doom and gloom, but to me there is an immediate thing we can all do to help out, which is to just switch off our lights. Yeah, that's a good point. When the porch light comes on when I get home, I only really notice it. Yeah, that's a good point. When the porch light comes on when I get home, I only really need it to light the front door. Half a lampshade could stop a lot of that light spilling out into the environment. That's a great point. With adequate regulations in place, we could make sure that human spaces are designed to be as friendly to insects as possible. A great suggestion. So there are things we can do as individuals and also things we need to sort out as a collective. So turn your lights out and let elected officials know that this is an issue you care about. And our theme is Wildflowers by Scott Holmes with sound effects downloaded from Zapsclat.