{"id":231887,"date":"2025-10-22T12:45:12","date_gmt":"2025-10-22T12:45:12","guid":{"rendered":"https:\/\/www.newsbeep.com\/ca\/231887\/"},"modified":"2025-10-22T12:45:12","modified_gmt":"2025-10-22T12:45:12","slug":"how-mountain-gorillas-defy-the-rules-of-reproduction-and-survival","status":"publish","type":"post","link":"https:\/\/www.newsbeep.com\/ca\/231887\/","title":{"rendered":"How mountain gorillas defy the rules of reproduction and survival"},"content":{"rendered":"<p>Female mountain gorillas don\u2019t simply fade after giving birth to their offspring. Many keep living \u2013 vigorous and socially engaged \u2013 for a decade or more beyond the years of reproduction, according to a new study.\u00a0<\/p>\n<p>The study is based on more than 30 years of observations in Uganda\u2019s Bwindi Impenetrable National Park.\u00a0<\/p>\n<p><a href=\"https:\/\/earthsnap.onelink.me\/3u5Q\/ags2loc4\" rel=\"noopener nofollow\" target=\"_blank\">&#13;<br \/>\n    <img decoding=\"async\" class=\"fit-picture\" loading=\"lazy\" src=\"https:\/\/www.newsbeep.com\/ca\/wp-content\/uploads\/2025\/10\/earthsnap-banner-news.webp.webp\" alt=\"EarthSnap\"\/>&#13;<br \/>\n<\/a><\/p>\n<p>The findings add <a href=\"https:\/\/www.earth.com\/news\/mountain-gorillas-have-their-own-strategy-to-avoid-inbreeding\/\" rel=\"nofollow noopener\" target=\"_blank\">mountain gorillas<\/a> to the short list of mammals with a substantial post-reproductive lifespan, including humans, a few whale species, and one chimpanzee population.<\/p>\n<p>The research was led by the <a href=\"https:\/\/www.eva.mpg.de\/index\/\" target=\"_blank\" rel=\"noreferrer noopener nofollow\">Max Planck Institute for Evolutionary Anthropology<\/a> and the <a href=\"https:\/\/www.utu.fi\/en\" target=\"_blank\" rel=\"noreferrer noopener nofollow\">University of Turku<\/a>.<\/p>\n<p>A rare pattern in the animal world<\/p>\n<p>Most female animals reproduce until they die. That\u2019s why a long life beyond reproduction has puzzled biologists for decades.\u00a0<\/p>\n<p>In humans and some whales, \u201cgrandmother\u201d effects \u2013 where older females boost the survival of kin \u2013 are one explanation. Whether something similar operates in gorillas has been an open question, largely because definitive, long-term field data have been scarce.<\/p>\n<p>This study changes that. Tracking four wild groups across three decades, the researchers found that nearly one-third of adult females stopped reproducing yet survived more than ten years afterward.\u00a0<\/p>\n<p>Given that wild female mountain gorillas rarely reach 50, that post-reproductive span represents at least a quarter of adult life.\u00a0<\/p>\n<p>\u201cWe wanted to formally test the presence of long post-reproductive <a href=\"https:\/\/www.earth.com\/news\/animals-species-some-live-days-others-for-centuries-maximum-lifespan-potential-mlsp\/\" rel=\"nofollow noopener\" target=\"_blank\">lifespan<\/a> in mountain gorillas, as we had observed old females that had ceased reproduction for a long time, yet still appeared in very good health,\u201d said senior author Martha Robbins, who directs the Bwindi project.\u00a0<\/p>\n<p>\u201cTwo females that were mature when we started the study in 1998 are still alive, yet had their last offspring in 2010.\u201d<\/p>\n<p>Menopause \u2013 or something like it?<\/p>\n<p>Pinning down a true menopause in wild animals is difficult. Demonstrating a sustained stop in births is one thing. Showing that ovarian function has permanently shut down is another, and requires hormonal data that are tough to collect in remote forests.\u00a0<\/p>\n<p>Even so, several lines of evidence point toward a <a href=\"https:\/\/www.earth.com\/news\/new-pill-reduces-menopause-symptoms-hot-flashes-by-73-percent-without-hormones\/\" rel=\"nofollow noopener\" target=\"_blank\">menopause<\/a>-like transition in mountain gorillas: extended birthless years in older females, reduced or absent mating, and previous endocrine hints of waning ovarian activity late in life.\u00a0<\/p>\n<p>\u201cThe evolutionary pressures which might have favored the evolution of post-reproductive lifespan, or even menopause, in gorillas remain unclear \u2013 we are still far from deciphering the evolutionary roots of these traits in gorillas and beyond,\u201d noted study lead author Nikos Smit.<\/p>\n<p>Mountain gorillas thrive after reproduction<\/p>\n<p>In humans and some whales, post-reproductive females can lift the survival odds of children and grandchildren by sharing knowledge, food, and social support.\u00a0<\/p>\n<p>Mountain gorilla societies are cohesive and hierarchical, with older females often playing stabilizing roles in their groups. They may influence foraging decisions, mediate conflict, or bolster the wellbeing of descendants, even if they\u2019re not direct caregivers.\u00a0<\/p>\n<p>The new findings don\u2019t prove a gorilla version of the \u201cgrandmother hypothesis,\u201d but they make it plausible \u2013 and worth testing.<\/p>\n<p>The broader evolutionary story<\/p>\n<p>The gorilla result rests on a rare scientific asset: continuous, individual-based tracking over decades. Without known ages and life histories, long gaps between births could be mistaken for post-reproductive life or vice versa.\u00a0<\/p>\n<p>The Bwindi record, built by daily observations of habituated groups, provides the resolution needed to say, with confidence, that many females truly stop reproducing and keep on living.<\/p>\n<p>That timeline also helps place gorillas in our broader evolutionary story. If a substantial post-reproductive lifespan appears in mountain gorillas as well as humans and <a href=\"https:\/\/www.earth.com\/news\/whale-songs-share-very-similar-patterns-with-human-language\/\" rel=\"nofollow noopener\" target=\"_blank\">whales<\/a>, the roots of human menopause may reach deeper into the great ape family tree than once assumed.<\/p>\n<p>At minimum, the study widens the comparative map: <a href=\"https:\/\/www.earth.com\/news\/human-bodies-undergo-very-rapid-change-aging-at-two-very-specific-times\/\" rel=\"nofollow noopener\" target=\"_blank\">human aging<\/a> is unusual, but perhaps not unique, in its long, productive years beyond the last birth.<\/p>\n<p>Female gorillas beyond reproduction <\/p>\n<p>The researchers call for targeted hormone studies to confirm whether Bwindi\u2019s older females experience a physiological menopause.\u00a0<\/p>\n<p>They also want to understand what post-reproductive females do for their groups: Do they help rear grand-offspring? Do they reduce stress or conflict? Do their presence and experience improve survival for kin?\u00a0<\/p>\n<p>Answering those questions could reveal why natural selection keeps this life stage around.<\/p>\n<p>For now, the headline is simple and striking: many female mountain gorillas live well past their reproductive years.\u00a0<\/p>\n<p>That single fact reshapes how we think about aging in one of our closest relatives and offers a fresh angle on how, and why, humans evolved to live long after reproduction ends.<\/p>\n<p>The study is published in the journal <a href=\"https:\/\/www.pnas.org\/doi\/10.1073\/pnas.2510998122\" target=\"_blank\" rel=\"noreferrer noopener nofollow\">Proceedings of the National Academy of Sciences<\/a>.<\/p>\n<p>\u2014\u2013<\/p>\n<p>Like what you read? <a href=\"https:\/\/www.earth.com\/subscribe\/\" rel=\"nofollow noopener\" target=\"_blank\">Subscribe to our newsletter<\/a> for engaging articles, exclusive content, and the latest updates.<\/p>\n<p>Check us out on <a href=\"https:\/\/www.earth.com\/earthsnap\/\" rel=\"nofollow noopener\" target=\"_blank\">EarthSnap<\/a>, a free app brought to you by <a href=\"https:\/\/www.linkedin.com\/in\/eric-ralls\/\" rel=\"nofollow noopener\" target=\"_blank\">Eric Ralls<\/a> and Earth.com.<\/p>\n<p>\u2014\u2013<\/p>\n","protected":false},"excerpt":{"rendered":"Female mountain gorillas don\u2019t simply fade after giving birth to their offspring. Many keep living \u2013 vigorous and&hellip;\n","protected":false},"author":2,"featured_media":231888,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[26],"tags":[49,48,66,323],"class_list":{"0":"post-231887","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-wildlife","8":"tag-ca","9":"tag-canada","10":"tag-science","11":"tag-wildlife"},"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/posts\/231887","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/comments?post=231887"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/posts\/231887\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/media\/231888"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/media?parent=231887"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/categories?post=231887"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/tags?post=231887"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}