{"id":7951,"date":"2023-08-07T15:33:02","date_gmt":"2023-08-07T12:33:02","guid":{"rendered":"https:\/\/www.cfwt.sua.ac.tz\/ecosystems\/?p=7951"},"modified":"2023-08-07T15:33:04","modified_gmt":"2023-08-07T12:33:04","slug":"oil-palms-attract-macaques-and-boars-impacting-biodiversity","status":"publish","type":"post","link":"https:\/\/www.cfwt.sua.ac.tz\/ecosystems\/news\/oil-palms-attract-macaques-and-boars-impacting-biodiversity","title":{"rendered":"Oil Palms Attract Macaques and Boars, Impacting Biodiversity"},"content":{"rendered":"<div class=\"bulletpoints\">\n<ul>\n<li><em>A new study documents the \u201chyperabundance\u201d of two generalist mammals around oil palm plantations in Southeast Asia, highlighting the indirect ecological impacts of oil palm expansion across the region.<\/em><\/li>\n<li><em>The research team found local numbers of wild pigs and macaques \u201cexploded\u201d in proximity to oil palm plantations, where they believe the animals derive enormous fitness benefits by consuming high-calorie palm fruit.<\/em><\/li>\n<li><em>Scientists caution that while these species can aggregate in some areas, their overall numbers are in decline due to a wide range of threats, including habitat loss, environmental degradation, disease outbreak, and poaching for the pet trade and biomedical research.<\/em><\/li>\n<li><em>The researchers <a title=\"Call for proposals: Conservation of Terrestrial Landscapes and Buffer Zones\" href=\"https:\/\/www.cfwt.sua.ac.tz\/ecosystems\/news\/call-for-proposals-conservation-of-terrestrial-landscapes-and-buffer-zones\">call for the establishment of buffer zones<\/a> around oil palm plantations and avoiding encroachment into intact forest as a way to address any problems arising from negative human-wildlife interactions and ecological impacts.<\/em><\/li>\n<\/ul>\n<\/div>\n<p>Many <a title=\"Wild Animal Small Grants Program\" href=\"https:\/\/www.cfwt.sua.ac.tz\/ecosystems\/news\/wild-animal-small-grants-program\">wild animals<\/a> are wise to the fact that where there are humans, there is typically food \u2014 often a cornucopia of food. A new study documents dramatically elevated numbers of two generalist mammals around oil palm plantations in Southeast Asia, where the <a title=\"Researcher in Applied Entomology in Fruit Trees for the Sustainable Plant Protection Program\" href=\"https:\/\/www.cfwt.sua.ac.tz\/ecosystems\/news\/researcher-in-applied-entomology-in-fruit-trees-for-the-sustainable-plant-protection-program\">research team believe they derive enormous benefits from eating high-calorie palm fruit<\/a>.<\/p>\n<p>The researchers looked at two decades\u2019 worth of camera trap <a title=\"Spatial Data Scientist\" href=\"https:\/\/www.cfwt.sua.ac.tz\/ecosystems\/news\/spatial-data-scientist\">data<\/a> in a range of degraded and intact habitats across the region, finding what they term a \u201chyperabundance\u201d of two monkey and two pig species \u2014 long-tailed macaques (Macaca fascicularis), pig-tailed macaques (M. nemestrina), bearded pigs (<em>Sus barbatus<\/em>) and wild boar (<em>S. scrofa<\/em>) \u2014 in proximity to oil palm plantations.<\/p>\n<p>While prior studies have documented wild boars and macaques \u201craiding\u201d plantations for palm fruit and their general preference for forest edge habitats, the intensity of their attraction to oil palm above all other land uses analyzed in the new study is more extreme than previously reported, Jonathan Moore, lead author of the study and Ph.D. candidate at the University of East Anglia in the U.K., told Mongabay.<\/p>\n<p>\u201cThese species are tolerant in <a title=\"Reversing Environmental Degradation in Africa and Asia \u2014 Project Grants\" href=\"https:\/\/www.cfwt.sua.ac.tz\/ecosystems\/news\/reversing-environmental-degradation-in-africa-and-asia-project-grants\">degraded<\/a> landscapes, but when you add oil palm into the mix, it just makes the populations explode,\u201d Moore said. \u201cThey have an unlimited food source [the palm fruit], and they can benefit and reproduce as much as they like, so there is no longer any limitation on their population size.\u201d<\/p>\n<p>These four <a title=\"Biodiversity: state of habitats and species\" href=\"https:\/\/www.cfwt.sua.ac.tz\/ecosystems\/news\/biodiversity-state-of-habitats-and-species\">species species accounted for some 80% of the 164,055 camera trap detections Moore and his colleagues analyzed across 58 separate habitats<\/a>. In landscapes with more than 60% oil palm coverage, wild boar and pig-tailed macaques were 337% and 447% more abundant respectively, compared to landscapes with very little oil palm. The team published their\u00a0<a href=\"https:\/\/onlinelibrary.wiley.com\/doi\/full\/10.1111\/brv.12985\" target=\"_blank\" rel=\"noopener external\" data-wpel-link=\"external\">findings<\/a>\u00a0in\u00a0<em>Biological Reviews.<\/em><\/p>\n<figure id=\"attachment_271790\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" class=\"size-full wp-image-271790\" src=\"https:\/\/imgs.mongabay.com\/wp-content\/uploads\/sites\/20\/2023\/08\/03152606\/Banner_Pig-tailed-macaque.jpg\" sizes=\"auto, (max-width: 2554px) 100vw, 2554px\" srcset=\"https:\/\/imgs.mongabay.com\/wp-content\/uploads\/sites\/20\/2023\/08\/03152606\/Banner_Pig-tailed-macaque.jpg 2554w, https:\/\/imgs.mongabay.com\/wp-content\/uploads\/sites\/20\/2023\/08\/03152606\/Banner_Pig-tailed-macaque-768x518.jpg 768w, https:\/\/imgs.mongabay.com\/wp-content\/uploads\/sites\/20\/2023\/08\/03152606\/Banner_Pig-tailed-macaque-1536x1036.jpg 1536w, https:\/\/imgs.mongabay.com\/wp-content\/uploads\/sites\/20\/2023\/08\/03152606\/Banner_Pig-tailed-macaque-2048x1382.jpg 2048w, https:\/\/imgs.mongabay.com\/wp-content\/uploads\/sites\/20\/2023\/08\/03152606\/Banner_Pig-tailed-macaque-610x412.jpg 610w\" alt=\"Pig-tailed macaque\" width=\"2554\" height=\"1723\" \/><figcaption class=\"wp-caption-text\">A camera-trap photo of a pig-tailed macaque in a lowland tropical forest in Southeast Asia. Image courtesy of Jonathan Moore.<\/figcaption><\/figure>\n<h3><strong>Cascading impacts on nearby ecosystems<\/strong><\/h3>\n<p>The gravitation of hefty herds of pigs and troops of macaques toward oil palm could have cascading impacts on the natural ecology of intact forests surrounding plantations. According to the study, both types of mammal are capable of outcompeting or predating on sensitive forest species, and wild boar have been shown to\u00a0<a href=\"https:\/\/news.mongabay.com\/2017\/12\/palm-oils-ecological-footprint-extends-to-distant-forests-study-finds\/\" target=\"_blank\" rel=\"noopener\" data-wpel-link=\"internal\">heavily degrade forest vegetation<\/a>\u00a0surrounding oil palm plantations when they\u2019re locally overly abundant.<\/p>\n<p>Scientists not involved in the study caution, however, that we must not overlook the many positive effects macaques and wild pigs have on ecosystems when they\u2019re present at normal population densities. Through seed dispersal and soil turnover, they enable forest plants to thrive, for instance, and by eating a wide range of prey, including rats, they provide natural <a title=\"Scientists make inroads against tree-killing pests\" href=\"https:\/\/www.cfwt.sua.ac.tz\/ecosystems\/news\/scientists-make-inroads-against-tree-killing-pests\">pest<\/a> control.<\/p>\n<p>Nadine Ruppert, a primatologist and <a title=\"Science Communication Course\" href=\"https:\/\/www.cfwt.sua.ac.tz\/ecosystems\/news\/science-communication-course\">conservation<\/a> biologist at Universiti Sains Malaysia, who was not involved in the study, questioned whether the new study\u2019s use of camera-trap data is a sufficiently reliable method of calculating abundances of group-living primates like macaques.<\/p>\n<p>\u201cThere\u2019s a few issues with camera trapping to calculate real abundances in open populations, such as how to assess independent sightings and avoid double counting the same individuals, and the quite different detection probabilities of arboreal and terrestrial species when using ground camera traps,\u201d Ruppert told Mongabay, adding that long-tailed macaques spend a lot of time in the tree canopy, whereas pig-tailed macaques are largely ground-dwelling.<\/p>\n<figure id=\"attachment_271803\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" class=\"size-full wp-image-271803\" src=\"https:\/\/imgs.mongabay.com\/wp-content\/uploads\/sites\/20\/2023\/08\/04050851\/3.-Bearded-pig_INBorneo_RAB.jpg\" sizes=\"auto, (max-width: 1200px) 100vw, 1200px\" srcset=\"https:\/\/imgs.mongabay.com\/wp-content\/uploads\/sites\/20\/2023\/08\/04050851\/3.-Bearded-pig_INBorneo_RAB.jpg 1200w, https:\/\/imgs.mongabay.com\/wp-content\/uploads\/sites\/20\/2023\/08\/04050851\/3.-Bearded-pig_INBorneo_RAB-768x512.jpg 768w, https:\/\/imgs.mongabay.com\/wp-content\/uploads\/sites\/20\/2023\/08\/04050851\/3.-Bearded-pig_INBorneo_RAB-610x407.jpg 610w\" alt=\"Bearded pig\" width=\"1200\" height=\"800\" \/><figcaption class=\"wp-caption-text\">A bearded pig eating rambutan fruit in Borneo. Image by Rhett A. Butler for Mongabay<\/figcaption><\/figure>\n<p>Ruppert said it\u2019s crucial that the new study findings aren\u2019t interpreted as a sign that the four species highlighted are doing well. The overall populations of all four species are struggling due to a wide range of differing threats, she said, including habitat loss, environmental degradation,\u00a0<a href=\"https:\/\/news.mongabay.com\/2021\/09\/borneos-bearded-pigs-and-traditional-hunters-adapted-to-oil-palms-then-came-swine-fever\/\" target=\"_blank\" rel=\"noopener\" data-wpel-link=\"internal\">disease outbreak<\/a>, and\u00a0<a href=\"https:\/\/news.mongabay.com\/2022\/08\/endangered-species-listing-of-long-tailed-macaques-shocking-painful-predictable-commentary\/\" target=\"_blank\" rel=\"noopener\" data-wpel-link=\"internal\">poaching<\/a>\u00a0for the pet trade and biomedical research.<\/p>\n<p>Bearded pig and wild boar populations have both suffered recent population crashes due to outbreaks of African swine fever that have ripped through parts of Southeast Asia since 2018. Meanwhile, long-tailed macaques and pig-tailed macaques are both listed as endangered on the IUCN Red List, with long-term monitoring <a title=\"Global Biodiversity Information Facility \u2014 Data Papers on Freshwater Species\" href=\"https:\/\/www.cfwt.sua.ac.tz\/ecosystems\/news\/global-biodiversity-information-facility-data-papers-on-freshwater-species\">data suggesting both species<\/a> are in sharp decline in many parts of their range.<\/p>\n<p>Kurnia Ilham, a long-tailed macaque researcher at Andalas University in Indonesia, who was not involved in the study, told Mongabay that long-tailed macaque numbers are in \u201csignificant\u201d decline in Indonesia. This is \u201ctied to habitat alteration, overexploitation for biomedical research and killing by local people due to crop damage,\u201d Kurnia told Mongabay in an email. \u201cWe urgently need to take the necessary measures to <a title=\"Climate change mitigation: reducing emissions\" href=\"https:\/\/www.cfwt.sua.ac.tz\/ecosystems\/news\/climate-change-mitigation-reducing-emissions\">mitigate<\/a> the extinction risk of this species.\u201d<\/p>\n<p>\u201cThese species need attention to better <a title=\"Protected and Conserved Area Fund\" href=\"https:\/\/www.cfwt.sua.ac.tz\/ecosystems\/news\/protected-and-conserved-area-fund\">protect<\/a> them \u2026 various populations are in fact declining,\u201d Ruppert said. \u201cIn these oil palm plantations where [pig-tailed macaques] seem to be thriving as mentioned in the new study, in fact, they could also be locally declining because in our study population in Perak [state in Malaysia] over the span of 10 years, we assessed infant mortality and that can sometimes reach 100% in a year. We\u2019re losing these young individuals and we think there could be issues with pesticides in agricultural landscapes that can have long-term effects on mammalian fitness that might not be immediately visible right now, but maybe will become a more concerning threat down the line, in two or three generations.\u201d<\/p>\n<figure id=\"attachment_271804\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" class=\"size-full wp-image-271804\" src=\"https:\/\/imgs.mongabay.com\/wp-content\/uploads\/sites\/20\/2023\/08\/04051026\/2.-Pig-tailed-macaque-baby.jpg\" sizes=\"auto, (max-width: 2361px) 100vw, 2361px\" srcset=\"https:\/\/imgs.mongabay.com\/wp-content\/uploads\/sites\/20\/2023\/08\/04051026\/2.-Pig-tailed-macaque-baby.jpg 2361w, https:\/\/imgs.mongabay.com\/wp-content\/uploads\/sites\/20\/2023\/08\/04051026\/2.-Pig-tailed-macaque-baby-768x522.jpg 768w, https:\/\/imgs.mongabay.com\/wp-content\/uploads\/sites\/20\/2023\/08\/04051026\/2.-Pig-tailed-macaque-baby-1536x1045.jpg 1536w, https:\/\/imgs.mongabay.com\/wp-content\/uploads\/sites\/20\/2023\/08\/04051026\/2.-Pig-tailed-macaque-baby-2048x1393.jpg 2048w, https:\/\/imgs.mongabay.com\/wp-content\/uploads\/sites\/20\/2023\/08\/04051026\/2.-Pig-tailed-macaque-baby-610x415.jpg 610w\" alt=\"Pig-tailed macaque camera-trap image\" width=\"2361\" height=\"1606\" \/><figcaption class=\"wp-caption-text\">A camera-trap photo of a young pig-tailed macaque in a forest clearing. Image courtesy of Jonathan Moore.<\/figcaption><\/figure>\n<p>Ruppert said the elevated numbers of animals around oil palm plantations is unlikely to be down to high population turnover or enhanced reproductive output. What is more likely at play is that animals are <a title=\"Mandatory biodiversity disclosures are coming\" href=\"https:\/\/www.cfwt.sua.ac.tz\/ecosystems\/news\/mandatory-biodiversity-disclosures-are-coming\">coming out of the forest<\/a> to \u201cseek out places near forest edges where humans are present,\u201d she said, so their numbers deeper in the forest are diminishing.<\/p>\n<p>\u201cFrom a human perspective, we may see 40 [macaques] in one open spot near the <a title=\"Postdoc \u2013 3D Modeling and Virtual Reality Creation of Natural Forest Environments\" href=\"https:\/\/www.cfwt.sua.ac.tz\/ecosystems\/news\/postdoc-3d-modeling-and-virtual-reality-creation-of-natural-forest-environments\">forest edge and automatically assume that there are maybe 400 more in the immediate natural<\/a> surroundings that we cannot see,\u201d she said. \u201cBut in reality, there might actually just be 40 macaques in the whole of the wider area, including the forest.\u201d<\/p>\n<h3><strong>Oil palm plantations need buffer zones<\/strong><\/h3>\n<p>Notwithstanding how local numbers compare to overall populations sizes, Moore agreed that the basic ecology of the four species highlighted in the study is not at fault. \u201cIt\u2019s not the animals \u2026 they\u2019re just taking advantage of a food source that they can consume easily,\u201d he said. \u201cIt\u2019s us as humans modifying the landscape and planting oil palm everywhere [that triggers] problems associated with hyperabundance.\u201d<\/p>\n<figure id=\"attachment_271802\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" class=\"size-full wp-image-271802\" src=\"https:\/\/imgs.mongabay.com\/wp-content\/uploads\/sites\/20\/2023\/08\/04050643\/4.-Wild-boars-cuddling.jpg\" sizes=\"auto, (max-width: 979px) 100vw, 979px\" srcset=\"https:\/\/imgs.mongabay.com\/wp-content\/uploads\/sites\/20\/2023\/08\/04050643\/4.-Wild-boars-cuddling.jpg 979w, https:\/\/imgs.mongabay.com\/wp-content\/uploads\/sites\/20\/2023\/08\/04050643\/4.-Wild-boars-cuddling-768x523.jpg 768w, https:\/\/imgs.mongabay.com\/wp-content\/uploads\/sites\/20\/2023\/08\/04050643\/4.-Wild-boars-cuddling-610x416.jpg 610w\" alt=\"Wild boars\" width=\"979\" height=\"667\" \/><figcaption class=\"wp-caption-text\">A camera-trap photo of wild boars in a lowland forest in Southeast Asia. Image courtesy of Jonathan Moore.<\/figcaption><\/figure>\n<p>Moore added that besides their impacts on nearby <a title=\"Forest ecosystems of Tanzania\" href=\"https:\/\/www.cfwt.sua.ac.tz\/ecosystems\/knowledge-base\/forest-ecosystems-of-tanzania\">forest ecosystems<\/a>, aggregations of pigs and macaques are often viewed as a nuisance, necessitating careful and at times expensive mitigation measures to manage their interactions with people.<\/p>\n<p>He also warned that aggregations of <a title=\"Wild Animal Initiative\" href=\"https:\/\/www.cfwt.sua.ac.tz\/ecosystems\/news\/wild-animal-initiative\">wild animals<\/a> in close proximity to humans can be potential disease reservoirs, heightening the risk of zoonotic disease transfer to humans. However, primate specialists not involved with the study told Mongabay that there\u2019s no data-backed evidence that either free-ranging macaques or wild pigs can communicate disease to humans.<\/p>\n<p>Moore and his colleagues called on the oil palm industry and <a title=\"Forest Governance Scholarship for PhD\" href=\"https:\/\/www.cfwt.sua.ac.tz\/ecosystems\/news\/forest-governance-scholarship-for-phd\">governments in producer countries to avoid encroachment into intact forest<\/a> and to establish buffer zones around plantations as a way to limit wildlife access to oil palm fruit and reduce the likelihood of large aggregations of generalist species and their associated knock-on consequences for surrounding forests and people.<\/p>\n<p>\u201cThere\u2019s not many ways to stop these species from going into the oil palm,\u201d Moore said. \u201cAvoiding building oil palm <a title=\"A Tree Girdling Beetle, Paranaleptes reticulata Thoms in Forest Plantation and Woodlots of Tanzania\" href=\"https:\/\/www.cfwt.sua.ac.tz\/ecosystems\/news\/a-tree-girdling-beetle-paranaleptes-reticulata-thoms-in-forest-plantation-and-woodlots-of-tanzania\">plantations close to forests<\/a> is the only way to really stop this from happening \u2026 otherwise the plantations will keep having these cascading effects.\u201d<\/p>\n<p><strong><em>Carolyn Cowan<\/em><\/strong><em>\u00a0is a staff writer for Mongabay. Follow her on Twitter\u00a0<\/em><a href=\"https:\/\/twitter.com\/CarolynCowan11\" target=\"_blank\" rel=\"external noopener\" data-wpel-link=\"external\"><em>@CarolynCowan11<\/em><\/a><em>.<\/em><\/p>\n<p><em>Banner image: A camera-trap photo of a pig-tailed macaque in a lowland tropical forest. Image courtesy of Jonathan Moore.<\/em><\/p>\n<p><strong>Citation:<\/strong><\/p>\n<p>Moore,\u00a0J.\u00a0H., Gibson,\u00a0L., Amir,\u00a0Z., Chanthorn,\u00a0W., Ahmad,\u00a0A.\u00a0H., Jansen,\u00a0P.\u00a0A., \u2026 Luskin,\u00a0M.\u00a0S. (2023). The rise of hyperabundant <a title=\"Invasive species versus native counterparts: nature\u2019s doppelg\u00e4ngers.\" href=\"https:\/\/www.cfwt.sua.ac.tz\/ecosystems\/news\/invasive-species-versus-native-counterparts-natures-doppelgangers\">native generalists threatens both humans and nature<\/a>.\u00a0<em>Biological Reviews<\/em>. doi:<a href=\"https:\/\/doi.org\/10.1111\/brv.12985\" target=\"_blank\" rel=\"external noopener\" data-wpel-link=\"external\">10.1111\/brv.12985<\/a><\/p>\n<p><strong>FEEDBACK:\u00a0<\/strong><a href=\"https:\/\/docs.google.com\/forms\/d\/e\/1FAIpQLSdwYikhkUZHBMgkZY-4fufZwd-SPyT66xsPyJoy8dYx1FYMaA\/viewform\" target=\"_blank\" rel=\"external noopener\" data-wpel-link=\"external\"><strong>Use this form<\/strong><\/a><strong>\u00a0to send a message to the author of this post. If you want to post a public comment, you can do that at the bottom of the page.<\/strong><\/p>\n<div id=\"single-article-footer\">\n<div id=\"single-article-meta\"><\/div>\n<\/div>\n","protected":false},"excerpt":{"rendered":"<p>A new study documents the \u201chyperabundance\u201d of two generalist mammals around oil palm plantations in Southeast Asia, highlighting the indirect ecological impacts of oil palm expansion across the region. The research team found local numbers of wild pigs and macaques \u201cexploded\u201d in proximity to oil palm plantations, where they believe the animals derive enormous fitness [&hellip;]<\/p>\n","protected":false},"author":2,"featured_media":7952,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[4],"tags":[],"class_list":["post-7951","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-news"],"_links":{"self":[{"href":"https:\/\/www.cfwt.sua.ac.tz\/ecosystems\/wp-json\/wp\/v2\/posts\/7951","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.cfwt.sua.ac.tz\/ecosystems\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.cfwt.sua.ac.tz\/ecosystems\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.cfwt.sua.ac.tz\/ecosystems\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.cfwt.sua.ac.tz\/ecosystems\/wp-json\/wp\/v2\/comments?post=7951"}],"version-history":[{"count":5,"href":"https:\/\/www.cfwt.sua.ac.tz\/ecosystems\/wp-json\/wp\/v2\/posts\/7951\/revisions"}],"predecessor-version":[{"id":7957,"href":"https:\/\/www.cfwt.sua.ac.tz\/ecosystems\/wp-json\/wp\/v2\/posts\/7951\/revisions\/7957"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.cfwt.sua.ac.tz\/ecosystems\/wp-json\/wp\/v2\/media\/7952"}],"wp:attachment":[{"href":"https:\/\/www.cfwt.sua.ac.tz\/ecosystems\/wp-json\/wp\/v2\/media?parent=7951"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.cfwt.sua.ac.tz\/ecosystems\/wp-json\/wp\/v2\/categories?post=7951"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.cfwt.sua.ac.tz\/ecosystems\/wp-json\/wp\/v2\/tags?post=7951"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}