{"id":30658,"date":"2026-08-01T10:50:00","date_gmt":"2026-08-01T14:50:00","guid":{"rendered":"https:\/\/www.ecoportal.net\/en\/?p=30658"},"modified":"2026-08-01T10:50:00","modified_gmt":"2026-08-01T14:50:00","slug":"twice-year-400-million-migrating-birds","status":"publish","type":"post","link":"https:\/\/www.ecoportal.net\/en\/twice-year-400-million-migrating-birds\/30658\/","title":{"rendered":"They checked 5 desert solar farms for the water birds everyone says mistake the panels for a lake, and not one bird was seen circling, approaching or landing on them"},"content":{"rendered":"<p>A heron lands on a solar panel in the desert,&nbsp;<strong>twelve miles<\/strong>&nbsp;from the nearest water.<\/p>\n<p>Field crews have recorded exactly that, and the image is&nbsp;<strong>hard to shake<\/strong>.<\/p>\n<p>The explanation everyone reaches for is that the glass looked like a lake to a bird that needed one.<\/p>\n<p>It is a tidy story, and teams have gone out repeatedly to confirm it.<\/p>\n<p>They keep coming back&nbsp;<strong>with almost nothing<\/strong>.<\/p>\n<h2>Where the lake idea came from<\/h2>\n<p>The physics underneath it is sound, which is why the idea spread so easily.<\/p>\n<p>Light bouncing off a smooth dark surface comes back&nbsp;<strong>horizontally polarized<\/strong>, and a still pond does exactly that.<\/p>\n<p>Insects that breed in water find it by reading that signature, since a body of water is otherwise hard to spot from the air.<\/p>\n<p>Researchers have documented the trap in detail. Asphalt, oil pools, black plastic sheeting, car roofs and glass all fool water seeking insects into landing and laying eggs.<\/p>\n<p>A photovoltaic panel is a smooth dark surface tilted toward the sky, so it produces&nbsp;<strong>the same signal<\/strong>.<\/p>\n<p>For insects, that evidence is solid and has been for years.<\/p>\n<p>The leap comes when the same logic gets extended&nbsp;<strong>upward to birds<\/strong>, and that step is where the support runs out.<\/p>\n<h2>What happened when biologists looked<\/h2>\n<p>Because somebody eventually went and checked, rather than reasoning from the optics.<\/p>\n<p>A team surveyed five utility scale sites across the American southwest, sitting in desert, grassland and farmland, and compared each one against a matched patch of ground nearby with no panels on it.<\/p>\n<p>If the panels were pulling birds down, the sites should have held more species than their reference plots.<\/p>\n<p>They did not. A real lake in the same region held&nbsp;<strong>far more birds<\/strong>&nbsp;than any solar site or reference plot.<\/p>\n<p>Dead bird counts came out almost identical between the two. On farmland the crews found five at the facility and six on the control ground.<\/p>\n<p>And in all that watching, nobody recorded a single bird&nbsp;<strong>circling, approaching or landing<\/strong>&nbsp;on a panel.<\/p>\n<p>A separate review pulled together 13 site years of carcass data from 10 photovoltaic plants, logging 669 birds in total.<\/p>\n<p>Water dependent species made up&nbsp;<strong>under 8 percent<\/strong>, and the authors state plainly that no study in the pile had tested a cause.<\/p>\n<h2>The numbers nobody puts beside it<\/h2>\n<p>Scale is the other thing missing from the usual version of this story.<\/p>\n<p>The one published estimate for large American solar puts annual bird deaths between&nbsp;<strong>37,800 and 138,600<\/strong>.<\/p>\n<p>That is a real number and not a trivial one.<\/p>\n<p>Buildings and glass kill somewhere between 365 million and 988 million birds a year in the same country.<\/p>\n<p>Fossil fuel power plants account for roughly 14.5 million, which puts solar at&nbsp;<strong>well under one percent<\/strong>&nbsp;of that alone.<\/p>\n<p>There is also a technology confusion running through the whole debate.<\/p>\n<p>The images people remember, of birds igniting in midair, come from&nbsp;<strong>concentrating solar towers<\/strong>&nbsp;that focus reflected heat onto a receiver.<\/p>\n<p>Only a couple of those exist in the United States, and they have nothing mechanically in common with a tilted photovoltaic panel.<\/p>\n<h2>What England found instead<\/h2>\n<p>Meanwhile a different question got asked on the other side of the Atlantic, and the answer was the opposite of the scare.<\/p>\n<p>Ecologists from a conservation charity and the University of Cambridge walked survey transects across solar sites in eastern England and counted what was living there.<\/p>\n<p>On intensively farmed arable land they averaged 12 birds per stretch of about 220 yards.<\/p>\n<p>On solar sites with hedgerow, rough grass and scrub left between the rows, the same stretch held&nbsp;<strong>35 birds<\/strong>, with diversity running two and a half times higher, as&nbsp;<a href=\"https:\/\/www.discoverwildlife.com\/environment\/solar-farms-benefit-bird-abundance-diversity\" target=\"_blank\" rel=\"noopener\">the survey<\/a>&nbsp;reported.<\/p>\n<p>Woodland species did roughly&nbsp;<strong>nine times better<\/strong>&nbsp;on the well managed sites.<\/p>\n<p>The panels were not the variable.&nbsp;<strong>The ground was<\/strong>.<\/p>\n<p>A site mown to bare gravel is a parking lot, while the same site with cover between the rows is habitat, and that distinction decides the outcome at a&nbsp;<a href=\"https:\/\/ecoportal.net\/en\/fox-lost-wild-home-solar-panels\/24938\/\" target=\"_blank\" rel=\"noopener\">solar site<\/a>&nbsp;the way it does at an&nbsp;<a href=\"https:\/\/ecoportal.net\/en\/an-offshore-wind-farm-in-the-north-sea\/28240\/\" target=\"_blank\" rel=\"noopener\">offshore project<\/a>.<\/p>\n<h2>What to do with the ground under the panels<\/h2>\n<p>So the useful question is not whether glass looks like water.<\/p>\n<p>It is what a developer does with the acres between and beneath the rows, which is space that produces nothing on its own.<\/p>\n<p>Several American states have started writing&nbsp;<strong>pollinator and grassland standards<\/strong>&nbsp;into permits for exactly that reason.<\/p>\n<p>None of this settles the heron. Water birds really do turn up at desert installations far from any water, and the reason remains&nbsp;<strong>genuinely unknown<\/strong>, as&nbsp;<a href=\"https:\/\/journals.plos.org\/plosone\/article?id=10.1371%2Fjournal.pone.0232034\" rel=\"nofollow noopener\" target=\"_blank\">the review<\/a>&nbsp;concedes.<\/p>\n<p>That is an honest gap, and it deserves the research money going into it rather than a confident explanation.<\/p>\n<p>What it does not deserve is&nbsp;<strong>a settled answer<\/strong>&nbsp;repeated until it sounds like one.<\/p>\n<p>Because the measurable effect of solar farms on birds turns out to depend less on the panels than on whatever is allowed to grow underneath them.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>A heron lands on a solar panel in the desert,&nbsp;twelve miles&nbsp;from the nearest water. Field crews have recorded exactly that, and the image is&nbsp;hard to shake. The explanation everyone reaches for is that the glass looked like a lake to a bird that needed one. It is a tidy story, and teams have gone out &#8230; <a title=\"They checked 5 desert solar farms for the water birds everyone says mistake the panels for a lake, and not one bird was seen circling, approaching or landing on them\" class=\"read-more\" href=\"https:\/\/www.ecoportal.net\/en\/twice-year-400-million-migrating-birds\/30658\/\" aria-label=\"Read more about They checked 5 desert solar farms for the water birds everyone says mistake the panels for a lake, and not one bird was seen circling, approaching or landing on them\">Read more<\/a><\/p>\n","protected":false},"author":28,"featured_media":30657,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"rank_math_focus_keyword":"year 400 million","rank_math_title":"They checked 5 desert solar farms for the water birds everyone says mistake the panels for a lake, and not one bird was seen circling, approaching or landing on them","rank_math_description":"Solar farms across the US are triggering a stunning optical illusion that fools waterbirds like herons and ducks into mistaking glass panels for lakes, wi","footnotes":""},"categories":[8],"tags":[],"class_list":["post-30658","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-energy"],"_links":{"self":[{"href":"https:\/\/www.ecoportal.net\/en\/wp-json\/wp\/v2\/posts\/30658","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=30658"}],"version-history":[{"count":0,"href":"https:\/\/www.ecoportal.net\/en\/wp-json\/wp\/v2\/posts\/30658\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.ecoportal.net\/en\/wp-json\/wp\/v2\/media\/30657"}],"wp:attachment":[{"href":"https:\/\/www.ecoportal.net\/en\/wp-json\/wp\/v2\/media?parent=30658"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.ecoportal.net\/en\/wp-json\/wp\/v2\/categories?post=30658"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.ecoportal.net\/en\/wp-json\/wp\/v2\/tags?post=30658"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}