The lane is dark except for one cold pool of white light.<\/p>\n
Under the hedge, a young man in a head torch is holding a pale canvas tray beneath a branch.<\/p>\n
He taps the branch with a stick, and whatever was feeding up there drops onto the fabric.<\/p>\n
He counts what landed, writes the number in a notebook, and moves along to the next stretch of hedge.<\/p>\n
He will do this for three summers<\/strong>.<\/p>\n What the tally comes to will surprise him more than anyone else<\/strong>.<\/p>\n Start with the thing that put the light there.<\/p>\n Trading orange sodium lamps for white LEDs was one of the easiest decisions in modern infrastructure.<\/p>\n An LED draws a fraction of the power for the same brightness on the road surface.<\/p>\n It lasts longer, needs fewer replacements, and pays for itself out of the electricity bill.<\/p>\n Households moved just as fast, and the American figures show how fast.<\/p>\n In 2015, only 4 percent of US homes used LEDs for most or all of their indoor lighting.<\/p>\n By 2020 that had reached 47 percent, and by 2024 it stood at 63 percent<\/strong>.<\/p>\n Nobody framed any of it as an ecological decision<\/strong>.<\/p>\n A hedgerow looks like a boundary and works like a corridor.<\/p>\n It is a strip of woodland edge running for miles across otherwise open farmland.<\/p>\n Hawthorn, blackthorn, oak and bramble grow together in it, and each one feeds a different set of insects.<\/p>\n Moth caterpillars sit on those leaves for weeks before they pupate.<\/p>\n They cannot fly away from a bad patch, which is exactly why they are worth counting.<\/p>\n An adult moth at a lamp only tells you where one moth went that night.<\/p>\n A caterpillar on a branch tells you what actually survived<\/strong> there.<\/p>\n And across southern England, a great many of those branches now sit directly beneath<\/strong> a road lamp.<\/p>\n Douglas Boyes was a doctoral student splitting his time between Newcastle University and the UK Centre for Ecology and Hydrology.<\/p>\n He chose 26 pairs of roadside sites across Oxfordshire, Buckinghamshire and Berkshire.<\/p>\n Each pair set a lit stretch against an unlit stretch of the same habitat close by.<\/p>\n Hedgerows were sampled in daylight with the beating tray, so no caterpillar was ever drawn toward a light while being counted.<\/p>\n Grass margins were swept after dark, when the caterpillars climb the stems to feed.<\/p>\n The work ran through the summers of 2018, 2019 and 2020.<\/p>\n It came to more than 400 hours<\/strong> in the field and over two thousand caterpillars in the notebook.<\/p>\n Boyes said afterward that he had expected the gap between lit and unlit to land somewhere near 10 percent<\/strong>.<\/p>\n It did not land anywhere near ten percent.<\/p>\n Caterpillar numbers in lit hedgerows ran 47 percent below the unlit controls, and in grass margins they were down 33 percent, according to the paper<\/a>.<\/p>\n Then the team split the results by lamp type, and the sharper finding appeared.<\/p>\n Under white LEDs the hedgerow figure was 52 percent<\/strong>, against 41 percent under high pressure sodium.<\/p>\n In grass margins the LED sites lost 43 percent while low pressure sodium lost only 11 percent.<\/p>\n The kind of lamp mattered more than the presence of a lamp, as the institute<\/a> put it at the time.<\/p>\n One further result from the same counts was harder to read.<\/p>\n Caterpillars from lit stretches weighed more, significantly so under LED, which the authors read as disrupted development<\/strong> rather than good news.<\/p>\n The authors were careful about scale, and any honest retelling has to be as well.<\/p>\n They estimate that only 1.1 percent of the land across their study region is directly lit above one lux.<\/p>\n Street lighting is a local pressure, and it is not the reason insect numbers are sliding across Europe as a whole.<\/p>\n Farming, habitat loss, pesticides and a warming climate all sit above it on that list.<\/p>\n What makes the result useful is that this particular pressure has a fix already sitting on the shelf.<\/p>\n Shields hold the light on the road instead of the hedge, warmer color temperatures cut the blue end, and dimming after midnight costs nothing at all.<\/p>\n The same argument about tradeoffs trails a solar site<\/a> or an offshore project<\/a> long after the engineering is settled.<\/p>\n Boyes died in the autumn of 2021, weeks after the paper ran, at the age of 25.<\/p>\n His colleagues named an award for him, and it goes to young recorders<\/strong>.<\/p>\n Which is roughly what 400 hours under a hedge in the dark was always meant to serve<\/strong>.<\/p>\n","protected":false},"excerpt":{"rendered":" The lane is dark except for one cold pool of white light. Under the hedge, a young man in a head torch is holding a pale canvas tray beneath a branch. He taps the branch with a stick, and whatever was feeding up there drops onto the fabric. He counts what landed, writes the number … Read more<\/a><\/p>\n","protected":false},"author":28,"featured_media":30636,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"rank_math_focus_keyword":"hedgerow moth caterpillars","rank_math_title":"A PhD student spent 400 hours counting moth caterpillars along English roadsides at night, and what the white LED lamps had done to the hedgerow was five times worse than he expected","rank_math_description":"LED bulbs promised cheaper, greener light for American homes. But a striking new finding reveals a 52 percent collapse in one creature living just past yo","footnotes":""},"categories":[83],"tags":[],"class_list":["post-30538","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-earth"],"_links":{"self":[{"href":"https:\/\/www.ecoportal.net\/en\/wp-json\/wp\/v2\/posts\/30538","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.ecoportal.net\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.ecoportal.net\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.ecoportal.net\/en\/wp-json\/wp\/v2\/users\/28"}],"replies":[{"embeddable":true,"href":"https:\/\/www.ecoportal.net\/en\/wp-json\/wp\/v2\/comments?post=30538"}],"version-history":[{"count":0,"href":"https:\/\/www.ecoportal.net\/en\/wp-json\/wp\/v2\/posts\/30538\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.ecoportal.net\/en\/wp-json\/wp\/v2\/media\/30636"}],"wp:attachment":[{"href":"https:\/\/www.ecoportal.net\/en\/wp-json\/wp\/v2\/media?parent=30538"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.ecoportal.net\/en\/wp-json\/wp\/v2\/categories?post=30538"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.ecoportal.net\/en\/wp-json\/wp\/v2\/tags?post=30538"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}The swap nobody argued about<\/h2>\n
Why a hedgerow is where you go looking<\/h2>\n
What 400 hours of fieldwork actually looks like<\/h2>\n
The number that came back instead<\/h2>\n
What that finding is, and what it is not<\/h2>\n