{"id":31466,"date":"2026-08-08T17:50:00","date_gmt":"2026-08-08T21:50:00","guid":{"rendered":"https:\/\/www.ecoportal.net\/en\/?p=31466"},"modified":"2026-08-08T17:50:00","modified_gmt":"2026-08-08T21:50:00","slug":"black-bears-drone-stress","status":"publish","type":"post","link":"https:\/\/www.ecoportal.net\/en\/black-bears-drone-stress\/31466\/","title":{"rendered":"Drones watched 4 black bears carry on grazing through 18 drone flights, and the monitors stitched under their skin caught 1 animal going from 41 to 162 heartbeats a minute"},"content":{"rendered":"<p>A bear stands in a harvested Minnesota cornfield with its head down, working steadily through the broken stalks.<\/p>\n<p>A small quadcopter comes over the treeline and holds position above it, and the animal&nbsp;<strong>does not look up<\/strong>.<\/p>\n<p>On the video it reads as an animal that could not care less about the thing above it.<\/p>\n<p>Sewn in under its skin is a monitor quietly recording&nbsp;<strong>something else entirely<\/strong>.<\/p>\n<p>The gap between those two records is the whole point, and it is&nbsp;<strong>bigger than anyone expected<\/strong>.<\/p>\n<h2>From 41 to 162<\/h2>\n<p>Four wild black bears carried implanted cardiac loggers while a drone was flown over them 18 separate times.<\/p>\n<p>Across all 18 flights, the animals showed&nbsp;<strong>a major behavioral change<\/strong>&nbsp;exactly twice.<\/p>\n<p>One of those two was a bear in a cornfield that ran roughly&nbsp;<strong>15 feet<\/strong>, then stopped and stood there watching the machine circle overhead.<\/p>\n<p>The heart data tells an entirely different story. The steepest response took one bear from 41 beats a minute to 162.<\/p>\n<p>That is&nbsp;<strong>a fourfold jump<\/strong>, and it happened in an animal that a camera would have logged as undisturbed.<\/p>\n<p>Every bear in the group showed the response to some degree, which is what makes this a pattern rather than one unusually nervous individual.<\/p>\n<h2>Why a calm animal can still be in trouble<\/h2>\n<p>The finding matters because of the way wildlife disturbance is normally judged in the first place.<\/p>\n<p>Almost every rule about how close a machine may come is written around&nbsp;<strong>what people can see<\/strong>, meaning does the animal flush, does it run, does it abandon a nest.<\/p>\n<p>A bear that keeps eating scores as perfectly fine under that test, and gets written down as undisturbed.<\/p>\n<p>But not moving is&nbsp;<strong>a strategy, not a verdict<\/strong>, and a large predator with nothing above it in the food chain has little reason to bolt from a noise.<\/p>\n<p>The lead researcher put the problem plainly, which is that not being able to see an effect does not mean there is no stress response happening.<\/p>\n<p>Until the loggers went in under the skin, nobody had&nbsp;<strong>a way of checking<\/strong>&nbsp;whether that test measured anything real.<\/p>\n<h2>How many machines are actually up there<\/h2>\n<p>The scale of this is not a niche research question, because the sky over rural America has filled up remarkably fast.<\/p>\n<p>Recreational registrations in the United States passed&nbsp;<strong>well over a million<\/strong>&nbsp;cumulative owners by the end of 2024, roughly 1.6 million of them.<\/p>\n<p>The active recreational fleet is a good deal smaller, around 455,000 aircraft, because plenty of people register once and then stop flying.<\/p>\n<p>Commercial registrations sit&nbsp;<strong>near 966,000<\/strong>, with roughly 388,000 in active service, and that side crossed a million during last year.<\/p>\n<p>Recreational growth is&nbsp;<strong>slowing noticeably<\/strong>, from about 7,900 new registrations a month down to 5,800.<\/p>\n<p>Commercial flying is doing the opposite of that, which means steadily more machines over farmland, forest and coastline rather than fewer.<\/p>\n<h2>The follow up almost nobody quotes<\/h2>\n<p>Here is the part that changes the conclusion, and it came from&nbsp;<strong>the same researcher<\/strong>&nbsp;four years later.<\/p>\n<p>A later study put loggers into five captive bears and flew over them repeatedly rather than once, as&nbsp;<a href=\"https:\/\/phys.org\/news\/2019-01-animals-drones.html\" target=\"_blank\" rel=\"noopener\">the follow up<\/a>&nbsp;describes.<\/p>\n<p>The animals habituated. Over roughly&nbsp;<strong>three to four weeks<\/strong>&nbsp;the heart response faded back toward normal, flight after flight.<\/p>\n<p>More striking, the habituation held through a&nbsp;<strong>118 day break<\/strong>&nbsp;with no flights at all, and did not reset when they started again.<\/p>\n<p>None of that cancels the first result, which stands exactly as it was published, as&nbsp;<a href=\"https:\/\/twin-cities.umn.edu\/news-events\/bears-appear-unfazed-drones-their-heart-rates-soar-u-m-research-shows\" rel=\"nofollow noopener\" target=\"_blank\">the work<\/a>&nbsp;reported at the time set out.<\/p>\n<p>It is the same pattern seen around an&nbsp;<a href=\"https:\/\/ecoportal.net\/en\/an-offshore-wind-farm-in-the-north-sea\/28240\/\" target=\"_blank\" rel=\"noopener\">offshore array<\/a>&nbsp;or a fenced&nbsp;<a href=\"https:\/\/ecoportal.net\/en\/fox-lost-wild-home-solar-panels\/24938\/\" target=\"_blank\" rel=\"noopener\">solar site<\/a>, where the first encounter and the fiftieth are not the same event.<\/p>\n<h2>What it means for a flight over open ground<\/h2>\n<p>The researcher&#8217;s own summary of all this is a good deal more balanced than either headline version of it.<\/p>\n<p>Close flights near wildlife should be avoided&nbsp;<strong>without a valid purpose<\/strong>, and a hobby flight over a feeding animal does not count as one.<\/p>\n<p>But drone work with a real job, such as counting a population or patrolling against poaching, appears to deliver that benefit&nbsp;<strong>without lasting harm<\/strong>.<\/p>\n<p>The caveat sits in the species. Bears are large, bold and hard to frighten, and habituation rates&nbsp;<strong>almost certainly vary<\/strong>&nbsp;from one animal to the next.<\/p>\n<p>An animal that nests on open ground, or one that already has predators coming from above, has far less room to shrug a machine off.<\/p>\n<p>What the loggers really proved is narrower and more useful, which is that a camera pointed at a calm animal is not evidence of anything at all.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>A bear stands in a harvested Minnesota cornfield with its head down, working steadily through the broken stalks. A small quadcopter comes over the treeline and holds position above it, and the animal&nbsp;does not look up. On the video it reads as an animal that could not care less about the thing above it. Sewn &#8230; <a title=\"Drones watched 4 black bears carry on grazing through 18 drone flights, and the monitors stitched under their skin caught 1 animal going from 41 to 162 heartbeats a minute\" class=\"read-more\" href=\"https:\/\/www.ecoportal.net\/en\/black-bears-drone-stress\/31466\/\" aria-label=\"Read more about Drones watched 4 black bears carry on grazing through 18 drone flights, and the monitors stitched under their skin caught 1 animal going from 41 to 162 heartbeats a minute\">Read more<\/a><\/p>\n","protected":false},"author":28,"featured_media":31467,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"rank_math_focus_keyword":"drone stress","rank_math_title":"Drones watched 4 black bears carry on grazing through 18 drone flights, and the monitors stitched under their skin caught 1 animal going from 41 to 162 heartbeats a minute","rank_math_description":"A University of Minnesota study strapped heart monitors to wild black bears and found a 400% stress spike from a single drone pass \u2014 even when the bear lo","footnotes":""},"categories":[83],"tags":[],"class_list":["post-31466","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\/31466","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=31466"}],"version-history":[{"count":0,"href":"https:\/\/www.ecoportal.net\/en\/wp-json\/wp\/v2\/posts\/31466\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.ecoportal.net\/en\/wp-json\/wp\/v2\/media\/31467"}],"wp:attachment":[{"href":"https:\/\/www.ecoportal.net\/en\/wp-json\/wp\/v2\/media?parent=31466"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.ecoportal.net\/en\/wp-json\/wp\/v2\/categories?post=31466"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.ecoportal.net\/en\/wp-json\/wp\/v2\/tags?post=31466"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}