{"id":531159,"date":"2026-03-18T16:47:15","date_gmt":"2026-03-18T16:47:15","guid":{"rendered":"https:\/\/www.newsbeep.com\/us\/531159\/"},"modified":"2026-03-18T16:47:15","modified_gmt":"2026-03-18T16:47:15","slug":"monarch-butterflies-in-mexico-forests-rebounded-slightly-this-year","status":"publish","type":"post","link":"https:\/\/www.newsbeep.com\/us\/531159\/","title":{"rendered":"Monarch butterflies in Mexico forests rebounded slightly this year"},"content":{"rendered":"

For the past quarter century, the future of monarch butterflies has looked dire, with these iconic American insects flitting toward extinction. Now, however, there is at least a small reason for hope: New data from WWF Mexico, a large conservation group, offers further evidence that the decline of eastern monarchs \u2014 the world\u2019s largest population \u2014 has stopped, even as the insects face worsening threats across their range.<\/p>\n

Each fall, tens of millions of monarchs that live east of the Rocky Mountains migrate, rather miraculously, to the same forested region of central Mexico. The featherweight insects can be so plentiful there during winter that the tree branches droop under their collective weight.<\/p>\n

In December and January, researchers hike into the forest and measure the area of monarch-covered trees to estimate how abundant they are. And this winter, the numbers were up \u2014 monarchs aggregated in trees covering about 7.2 acres of forest in Mexico, up substantially from 4.4 acres the year before and from 2.2 acres the year before that.<\/p>\n

The new numbers are still way below the average from the first 10 years of monitoring (about 21 acres) and what scientists consider sustainable (about 15 acres). But they still amount to good news, said Karen Oberhauser, a professor emeritus at the University of Wisconsin Madison, and one of the nation\u2019s leading monarch experts.<\/p>\n

\u201cWe are in a period of relative stability where the population has stopped declining,\u201d Oberhauser, who was not involved in the new WWF Mexico report, told me.<\/p>\n

Oberhauser largely attributes the latest monarch bump to weather \u2014 there was plenty of rain last year in the middle of the country, along the butterflies\u2019 migratory path, providing adult monarchs with lots of flowers to feed on. But it\u2019s also a sign, she said, that scattered efforts<\/a> across<\/a> the country<\/a> to restore milkweed are helping monarchs hold on. (Even in the middle of New York City, small private gardens and city parks are fueling monarchs<\/a>.)<\/p>\n

\u201cOur efforts can make a difference,\u201d Oberhauser said.<\/p>\n

\"Tons<\/a><\/p>\n

Monarch butterflies aggregate on oyamel fir trees in Michoacan, Mexico, in winter 2022. Claudio Cruz\/AFP via Getty Images<\/p>\n

The crash in US monarch populations is largely rooted in perhaps an unexpected source: genetically modified seeds. A few decades ago, farmers across the Midwest began planting new corn and soybean seeds that were modified to withstand a common herbicide known as glyphosate. That made it easier for farmers to spray their fields and kill the weeds growing in them.<\/p>\n

Milkweed, the only plant that monarch caterpillars can eat, was one such weed. And as it vanished in the 1990s, so did monarchs.<\/p>\n

Responding to this decline, the Biden administration proposed at the end of 2024 to list monarchs as threatened under the Endangered Species Act, the strongest wildlife law in the country. Before the listing was finalized, however, Donald Trump\u2019s second term began. In September, his administration punted the decision<\/a>, and indicated<\/a> it would not make a final rule in the next 12 months. A spokesperson for the US Fish and Wildlife Service confirmed that it does not expect to issue a final rule before late September 2026.<\/p>\n

Two environmental groups have since sued<\/a> the US Fish and Wildlife Service \u2014 the federal agency that enforces the Endangered Species Act \u2014 in an effort to set a binding date<\/a> by which it needs to finalize the rule. When that happens, it\u2019s possible that the administration could grant the species protection or reverse course and decide that protection isn\u2019t warranted, said Lori Nordstrom, a retired Fish and Wildlife Service official, who was closely involved in the 2024 proposal to list monarchs as threatened.<\/p>\n

\u201cThe US Fish and Wildlife Service continues to evaluate the monarch butterfly using the best available science and in accordance with all requirements of the Endangered Species Act,\u201d the agency spokesperson told Vox. \u201cThe administration continues to emphasize voluntary, locally driven conservation as a proven tool for supporting species and reducing the need for additional federal regulation.\u201d<\/p>\n

Still, however, both eastern and western<\/a> monarch populations are at historic lows. Good weather can certainly boost their numbers for a year, like we have seen last winter. But bad weather, too, can precipitate future declines \u2014 and monarch populations don\u2019t have much room for more loss. Researchers suspect<\/a> that climate change is likely to worsen weather conditions for monarchs.<\/p>\n

To truly stabilize monarch populations \u2014 and to make them more resilient in the face of further warming \u2014 they will need more than a few patches of milkweed. \u201cWe need to regain a lot of habitat to be able to get numbers back up,\u201d Nordstrom said. \u201cWe are still a long way from where we need to be.\u201d<\/p>\n","protected":false},"excerpt":{"rendered":"For the past quarter century, the future of monarch butterflies has looked dire, with these iconic American insects…\n","protected":false},"author":2,"featured_media":531160,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[47],"tags":[1687,9168,192,79],"class_list":{"0":"post-531159","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-environment","8":"tag-climate","9":"tag-down-to-earth","10":"tag-environment","11":"tag-science"},"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/posts\/531159","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/comments?post=531159"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/posts\/531159\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/media\/531160"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/media?parent=531159"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/categories?post=531159"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/tags?post=531159"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}