Chimpanzee mothers may carry dead infants longer depending on infant age, cause of death, maternal care, and temperature.<\/p>\n
Humans are not the only animals that stay close to the dead. <\/p>\n
Chimpanzee and bonobo mothers sometimes continue carrying an infant after it has died, sometimes for a few hours and sometimes for many weeks.<\/p>\n
That behavior matters because it touches a difficult question: what does another animal<\/a> understand about death? <\/p>\n Looking at these mothers may help researchers think about how human responses to death developed over evolutionary time.<\/p>\n Chimpanzee mothers carry infants longer<\/p>\n The behavior is known as infant corpse carrying. It is widely reported in primates<\/a>, but the reason one mother stops quickly while another keeps carrying for days has been difficult to explain.<\/p>\n A new analysis found that carrying time was linked most clearly with how the infant died. <\/p>\n Older infants also tended to be carried longer, and mothers at sites with longer gaps between births tended to continue carrying for longer.<\/p>\n Comparing multiple studies<\/p>\n The work was led by Reece Hammond, a doctoral candidate at the University of Oxford<\/a>. <\/p>\n Dr. Thomas A. P\u00fcschel, Wendy James Associate Professor in Evolutionary Anthropology, also worked on the analysis.<\/p>\n \u201cBy bringing together a large multisite sample of ICC cases from 15 distinct sites we can draw species<\/a>-level generalizable conclusions about the behavior: this is something that cannot be done by using cases from just one site or subspecies,\u201d Hammond said.<\/p>\n \u201cThis means that our findings can be used to make inferences as to the evolution of death related behavior in humans after we diverged from chimpanzees some 6-8 million years ago.\u201d<\/p>\n Looking beyond one group<\/p>\n Instead of watching a single chimpanzee community, the team brought together 83 published cases from 15 sites. <\/p>\n Most involved chimpanzees<\/a>, while only four involved bonobos.<\/p>\n The shortest carrying event lasted about 30 minutes. The longest continued for 126 days, while the average lasted a little over 11 days.<\/p>\n The researchers compared carrying time with possible explanations including the infant\u2019s age, cause of death, the mother\u2019s age and experience, climate, group size, and whether mothers may have seen this behavior before.<\/p>\n Cause of death mattered<\/p>\n The clearest result involved how the infant died. <\/p>\n Infants that died from disease were carried longer than infants killed through infanticide, which means the killing of an infant by another member of the same species.<\/p>\n Other causes of death did not show the same clear difference from infanticide. The result should not be simplified to mean that all natural deaths lead to longer carrying.<\/p>\n One idea is that disease can make death less immediately obvious than a violent attack. <\/p>\n But some chimpanzee mothers have carried infants long after the bodies became mummified, when death would likely have been clear.<\/p>\n The authors also suggest that carrying after infanticide may sometimes bring social risks, such as further aggression. Their data could not test that possibility directly.<\/p>\n Older infants stayed longer<\/p>\n Infant age showed another pattern. Mothers tended to carry older infants for longer than younger ones.<\/p>\n The researchers used age as a rough sign of how long the mother-infant relationship<\/a> had developed. <\/p>\n This does not prove that a stronger emotional bond directly caused longer carrying, but it fits the idea that maternal behavior may continue after an infant dies.<\/p>\n Mothers living in populations with longer average gaps between births also tended to carry dead infants for longer. Those longer gaps can reflect a longer period of maternal care for each infant.<\/p>\n The authors suggest that maternal care may be so persistent that it does not immediately stop after death. <\/p>\n In that sense, corpse carrying may partly be a continuation of behavior that normally helps a mother care for a living infant.<\/p>\n Cooler weather may matter<\/p>\n Carrying also tended to last longer during cooler periods. This result was less reliable than the links with cause of death, infant age, and birth intervals.<\/p>\n One possible explanation is decomposition, the natural breakdown of a body after death. Cooler conditions can slow that process and may delay some of the strong smells linked with decay.<\/p>\n The paper discusses putrescine, a chemical produced during decomposition that chimpanzees<\/a> avoid in experiments. <\/p>\n The researchers did not measure this chemical in the 83 cases, so its role remains only a possible explanation.<\/p>\n The temperature link also disappeared in some alternative analyses. It should therefore be treated more cautiously than the other main findings.<\/p>\n What this says about death<\/p>\n The most important point is what the findings do not show. They do not prove that chimpanzees or bonobos understand death in the same way humans do, and they do not prove that these animals fail to understand it.<\/p>\n \u201cOur findings show that we don\u2019t need to assume that chimpanzee and bonobo mothers understand death as irreversible to explain how long they carry their dead infants,\u201d Dr. P\u00fcschel said. <\/p>\n \u201cThe patterns can be explained by the persistence of maternal behavior and by social, life-history and environmental factors, but importantly, that does not mean these animals are incapable of recognizing death.\u201d<\/p>\n Maternal care may persist<\/p>\n A mother may continue carrying because the behavior tied to caring for an infant does not stop at once. <\/p>\n How long it lasts may also depend on the infant\u2019s age, the circumstances of death, the normal length of maternal care, and possibly the condition of the body.<\/p>\n That is why the behavior matters beyond chimpanzees themselves. <\/p>\n It offers a way to examine the basic pieces of behavior around death without assuming that another species thinks about death exactly as humans do.<\/p>\n Important limits remain<\/p>\n The analysis used published observations collected by different teams at different places, and many cases were missing information for some factors. The bonobo sample was especially small, with only four cases.<\/p>\n Climate was measured at the site level rather than directly around each body. Some ideas, such as whether mothers learn corpse carrying by watching others, were also difficult to measure accurately.<\/p>\n Even with those limits, cause of death remained the most consistent clue to carrying duration. The wider pattern points to persistent maternal care, infant age, local reproductive patterns, and perhaps temperature.<\/p>\n For humans, the value of the work is not that it gives a simple answer about animal grief or awareness. <\/p>\n It shows how behavior around death may emerge from several social and biological processes, offering another clue about how human responses to death may have evolved.<\/p>\n The study is published in the journal Biology Letters<\/a>.<\/p>\n \u2014\u2013<\/p>\n Like what you read? Subscribe to our newsletter<\/a> for engaging articles, exclusive content, and the latest updates.<\/p>\n Check us out on EarthSnap<\/a>, a free app brought to you by Eric Ralls<\/a> and Earth.com.<\/p>\n \u2014\u2013<\/p>\n","protected":false},"excerpt":{"rendered":"Chimpanzee mothers may carry dead infants longer depending on infant age, cause of death, maternal care, and temperature.…\n","protected":false},"author":2,"featured_media":629533,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[26],"tags":[61,60,82,263],"class_list":["post-629532","post","type-post","status-publish","format-standard","has-post-thumbnail","category-wildlife","tag-ie","tag-ireland","tag-science","tag-wildlife"],"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/posts\/629532","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/comments?post=629532"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/posts\/629532\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/media\/629533"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/media?parent=629532"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/categories?post=629532"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/tags?post=629532"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}