Displaying publications 1 - 20 of 44 in total

Abstract:
Sort:
  1. Smith TM, Arora M, Austin C, Nunes Ávila J, Duval M, Lim TT, et al.
    Elife, 2024 Mar 08;12.
    PMID: 38457350 DOI: 10.7554/eLife.90217
    Studies of climate variation commonly rely on chemical and isotopic changes recorded in sequentially produced growth layers, such as in corals, shells, and tree rings, as well as in accretionary deposits-ice and sediment cores, and speleothems. Oxygen isotopic compositions (δ18O) of tooth enamel are a direct method of reconstructing environmental variation experienced by an individual animal. Here, we utilize long-forming orangutan dentitions (Pongo spp.) to probe recent and ancient rainfall trends on a weekly basis over ~3-11 years per individual. We first demonstrate the lack of any consistent isotopic enrichment effect during exclusive nursing, supporting the use of primate first molar teeth as environmental proxies. Comparisons of δ18O values (n=2016) in twelve molars from six modern Bornean and Sumatran orangutans reveal a high degree of overlap, with more consistent annual and bimodal rainfall patterns in the Sumatran individuals. Comparisons with fossil orangutan δ18O values (n=955 measurements from six molars) reveal similarities between modern and late Pleistocene fossil Sumatran individuals, but differences between modern and late Pleistocene/early Holocene Bornean orangutans. These suggest drier and more open environments with reduced monsoon intensity during this earlier period in northern Borneo, consistent with other Niah Caves studies and long-term speleothem δ18O records in the broader region. This approach can be extended to test hypotheses about the paleoenvironments that early humans encountered in southeast Asia.
    Matched MeSH terms: Pongo pygmaeus
  2. Unwin S, Commitante R, Moss A, Bridges E, Farmer KH, Jaya RL, et al.
    Am J Primatol, 2021 May 21.
    PMID: 34018623 DOI: 10.1002/ajp.23273
    One Health is increasingly being used as a tool in ecosystem protection. The Orangutan Veterinary Advisory Group (OVAG) is working to address One Health concerns in Pongo spp. (orangutan) welfare and conservation. Orangutans are vital contributors to the ecosystem health of their range areas. Strengthening national capacity is crucial to make a lasting difference in the currently bleak outlook for orangutan species survival. OVAG is a capacity strengthening and expertise network that brings together all those working with orangutans, in- and ex-situ, to share knowledge, skills, and to collectively learn. Using the One Health paradigm embedded to enhance professional development, the OVAG network is successfully supporting conservation outcomes and impact. As part of our adaptive management approach, and to assess individual and organizational change attributable to the capacity strengthening work of OVAG, we evaluated technical skill test data, program satisfaction data, and asked participants to complete a self-reflective survey. This pilot study of our work demonstrates statistically significant improvements in conservation medicine (t = 5.481, p 
    Matched MeSH terms: Pongo pygmaeus
  3. Kamaluddin SN, Matsuda I, Md-Zain BM
    J Appl Anim Welf Sci, 2021 Apr 10.
    PMID: 33843367 DOI: 10.1080/10888705.2021.1910032
    Assessments of the welfare status of captive and semi-captive animals often compare how their expression of natural behaviors differs from that of free-ranging conspecifics. From December 2015-2016, we recorded and analyzed the activity budget and postural behaviors of three orangutans in Bukit Merah Orang Utan Island (BMOUI) to evaluate their welfare status. The orangutans' activity budget was dominated by resting (60%), feeding (13%), playing (14%), and moving (9%). Behavioral categories followed a similar trend: resting > feeding > moving > playing, except that the subadult male spent significantly more time playing than the two adults. The most predominant posture was sitting (47.0%), followed by pronograde standing (29.4%), lying (10.5%), and clinging (4.5%). Our results suggest that orangutans on BMOUI engage in less feeding but more resting, and show less postural diversity than free-ranging individuals. We propose that appropriate interventions to shift activity budgets, especially feeding vs. resting, and postural behaviors of captive orangutans toward those found in free-ranging orangutans might be beneficial for their welfare and survival.
    Matched MeSH terms: Pongo pygmaeus
  4. Ampeng A, Liam J, Simpson B, Traelholt C, Md Nor S, Abdan-Saleman MSB, et al.
    Biodivers Data J, 2021;9:e60753.
    PMID: 33531863 DOI: 10.3897/BDJ.9.e60753
    Wildlife surveys were conducted in Usun Apau National Park (UANP), Sarawak from Oct 2017 to Oct 2020. This was the first attempt to document fauna diversity in Usun Apau National Park on the UANP plateau at 1200-1400 m a.s.l. On 17 September 2020, 10 AM, we observed an orangutan individual, Pongo pygmaeus, over a period of one minute at Libut Camp UANP (E: 114039'.546, N: 2052'36.44) at 1,020 m a.s.l. We also recorded four nests and orangutan vocalisation twice. This observation is important for Bornean orangutan conservation as this was the first orangutan sighting in UANP and well outside the species distribution range for in Sarawak.
    Matched MeSH terms: Pongo pygmaeus
  5. Tamrin NAM, Zainudin R, Esa Y, Alias H, Isa MNM, Croft L, et al.
    Animals (Basel), 2020 Dec 10;10(12).
    PMID: 33321745 DOI: 10.3390/ani10122359
    Taste perception is an essential function that provides valuable dietary and sensory information, which is crucial for the survival of animals. Studies into the evolution of the sweet taste receptor gene (TAS1R2) are scarce, especially for Bornean endemic primates such as Nasalis larvatus (proboscis monkey), Pongo pygmaeus (Bornean orangutan), and Hylobates muelleri (Muller's Bornean gibbon). Primates are the perfect taxa to study as they are diverse dietary feeders, comprising specialist folivores, frugivores, gummivores, herbivores, and omnivores. We constructed phylogenetic trees of the TAS1R2 gene for 20 species of anthropoid primates using four different methods (neighbor-joining, maximum parsimony, maximum-likelihood, and Bayesian) and also established the time divergence of the phylogeny. The phylogeny successfully separated the primates into their taxonomic groups as well as by their dietary preferences. Of note, the reviewed time of divergence estimation for the primate speciation pattern in this study was more recent than the previously published estimates. It is believed that this difference may be due to environmental changes, such as food scarcity and climate change, during the late Miocene epoch, which forced primates to change their dietary preferences. These findings provide a starting point for further investigation.
    Matched MeSH terms: Pongo pygmaeus
  6. Testamenti VA, Surya M, Saepuloh U, Iskandriati D, Tandang MV, Kristina L, et al.
    Vet World, 2020 Nov;13(11):2459-2468.
    PMID: 33363342 DOI: 10.14202/vetworld.2020.2459-2468
    Background and Aim: Melioidosis is a potentially fatal disease affecting humans and a wide range of animal species; it is often underdiagnosed and underreported in veterinary medicine in Indonesia. This study aimed to characterize morphological and molecular features of Burkholderia pseudomallei, the causative agent of melioidosis which caused the death of a Bornean orangutan.

    Materials and Methods: Pulmonary abscess samples were cultured on several types of media, including Ashdown agar, Ashdown broth, and MacConkey agar. Type three secretion system orf 2 real-time polymerase chain reaction (PCR) and latex agglutination tests were performed to identify the bacteria. Morphological characteristics were compared to all previously published morphotypes. Subsequently, the bacteria were characterized by multilocus sequence typing (MLST) and Yersinia-like flagellum/Burkholderia thailandensis-like flagellum and chemotaxis PCR. The results of the genotyping were afterward compared to all genotypes from Southeast Asia.

    Results: Multiple morphotypes of B. pseudomallei were perceived during the growth on Ashdown agar. Furthermore, it was identified by MLST that the Type I and Type II morphotypes observed in this study were clones of a single ST, ST54, which is predominantly found in humans and the environment in Malaysia and Thailand, although a very limited number of reports was published in association with animals. Moreover, the E-BURST analysis showed that the ST is grouped together with isolates from Southeast Asian countries, including Malaysia, Thailand, Singapore, and Cambodia. ST54 was predicted to be the founding genotype of several STs from those regions.

    Conclusion: B. pseudomallei ST54 that caused the death of a Bornean orangutan has a distant genetic relationship with other STs which were previously reported in Indonesia, implying a vast genetic diversity in Indonesia that has not been discovered yet.

    Matched MeSH terms: Pongo pygmaeus
  7. Takeshita RSC, Mendonça RS, Bercovitch FB, Huffman MA
    PMID: 31549180 DOI: 10.1007/s00360-019-01235-7
    Non-invasive measures of stress are crucial for captive and conservation management programs. The adrenal hormone dehydroepiandrosterone-sulfate (DHEAS) has recently been adopted as a stress marker, but there is little investigation of its relationship to glucocorticoids (GC), well-known indicators of stress. This study examined the influence of age, reproductive state and environment on GC and DHEAS levels in orangutans, to test whether the GC/DHEAS ratio can provide an index of stress response in primates. We measured fecal GC (fGC) and fecal DHEAS (fDHEAS) concentrations in 7 captive orangutans from zoological parks in Japan and 22 wild orangutans from Danum Valley Conservation Area, Malaysia. We found that in a stressful condition (transportation), fDHEAS levels increased 2 days after the fGC response, which occurred 1 day after the stressor. One pregnant female had elevated levels of both hormones, and a higher fGC/fDHEAS ratio than baseline. Females in the first year of lactation had fGC levels and the fGC/fDHEAS ratio significantly higher than both baseline and females in the second and subsequent years of lactation. There was no effect of age on fGC levels, but the fGC/fDHEAS ratio was higher in infants than adults and adolescents. fDHEAS concentrations were lower in infants than juveniles, adolescents and adults, a phenomenon known as adrenarche, shared with humans and other great apes. We suggest that changes in DHEAS during orangutan life history are associated with changes in the dynamics of maintaining homeostasis that vary with age and reproductive state. The GC/DHEAS ratio index is useful to evaluate age-related abilities of responding to stressful challenges.
    Matched MeSH terms: Pongo pygmaeus/growth & development*; Pongo pygmaeus/physiology
  8. Seaman DJI, Bernard H, Ancrenaz M, Coomes D, Swinfield T, Milodowski DT, et al.
    Am J Primatol, 2019 08;81(8):e23030.
    PMID: 31328289 DOI: 10.1002/ajp.23030
    The conversion of forest to agriculture continues to contribute to the loss and fragmentation of remaining orang-utan habitat. There are still few published estimates of orang-utan densities in these heavily modified agricultural areas to inform range-wide population assessments and conservation strategies. In addition, little is known about what landscape features promote orang-utan habitat use. Using indirect nest count methods, we implemented surveys and estimated population densities of the Northeast Bornean orang-utan (Pongo pygmaeus morio) across the continuous logged forest and forest remnants in a recently salvage-logged area and oil palm plantations in Sabah, Malaysian Borneo. We then assessed the influence of landscape features and forest structural metrics obtained from LiDAR data on estimates of orang-utan density. Recent salvage logging appeared to have a little short-term effect on orang-utan density (2.35 ind/km 2 ), which remained similar to recovering logged forest nearby (2.32 ind/km 2 ). Orang-utans were also present in remnant forest patches in oil palm plantations, but at significantly lower numbers (0.82 ind/km 2 ) than nearby logged forest and salvage-logged areas. Densities were strongly influenced by variation in canopy height but were not associated with other potential covariates. Our findings suggest that orang-utans currently exist, at least in the short-term, within human-modified landscapes, providing that remnant forest patches remain. We urge greater recognition of the role that these degraded habitats can have in supporting orang-utan populations, and that future range-wide analyses and conservation strategies better incorporate data from human-modified landscapes.
    Matched MeSH terms: Pongo pygmaeus*
  9. Simon D, Davies G, Ancrenaz M
    PLoS One, 2019;14(7):e0218819.
    PMID: 31314781 DOI: 10.1371/journal.pone.0218819
    The Bornean orangutan is critically endangered and monitoring its population is needed to inform effective conservation management. In this paper, we present results of 2014-17 aerial nest surveys of the major orangutan populations in Sabah and compare them with baseline data produced during surveys conducted in 2002-03 using similar methods. Our results show three important points: a) by increasing the survey effort (estimated at 15-25% cover), sparsely scattered orangutan sub-populations not recorded in the previous aerial surveys were located and the accuracy of the nest count estimates is expected to improve; b) large populations in the interior forests of Sabah, occupying sustainably managed logged and unlogged forests, have been stable over 15 years and are of vital importance for the species' conservation; c) fragmented populations located in eastern Sabah, that are surrounded by extensive oil palm plantations, have declined at varying rates.
    Matched MeSH terms: Pongo pygmaeus/physiology*
  10. van Noordwijk MA, Utami Atmoko SS, Knott CD, Kuze N, Morrogh-Bernard HC, Oram F, et al.
    J Hum Evol, 2018 12;125:38-49.
    PMID: 30502896 DOI: 10.1016/j.jhevol.2018.09.004
    Orangutans (Pongo spp.) are reported to have extremely slow life histories, including the longest average interbirth intervals of all mammals. Such slow life history can be viable only when unavoidable mortality is kept low. Thus, orangutans' survivorship under natural conditions is expected to be extremely high. Previous estimates of orangutan life history were based on captive individuals living under very different circumstances or on small samples from wild populations. Here, we combine birth data from seven field sites, each with demographic data collection for at least 10 years (range 12-43 years) on wild orangutans to better document their life history. Using strict criteria for data inclusion, we calculated infant survival, interbirth intervals and female age at first reproduction, across species, subspecies and islands. We found an average closed interbirth interval of 7.6 years, as well as consistently very high pre-weaning survival for males and females. Female survival of 94% until age at first birth (at around age 15 years) was higher than reported for any other mammal species under natural conditions. Similarly, annual survival among parous females is very high, but longevity remains to be estimated. Current data suggest no major life history differences between Sumatran and Bornean orangutans. The high offspring survival is remarkable, noting that modern human populations seem to have reached the same level of survival only in the 20th century. The orangutans' slow life history illustrates what can be achieved if a hominoid bauplan is exposed to low unavoidable mortality. Their high survival is likely due to their arboreal and non-gregarious lifestyle, and has allowed them to maintain viable populations, despite living in low-productivity habitats. However, their slow life history also implies that orangutans are highly vulnerable to a catastrophic population crash in the face of drastic habitat change.
    Matched MeSH terms: Pongo pygmaeus/physiology*
  11. Meijaard E, Sherman J, Ancrenaz M, Wich SA, Santika T, Voigt M
    Curr Biol, 2018 11 05;28(21):R1241-R1242.
    PMID: 30399343 DOI: 10.1016/j.cub.2018.09.052
    A recent report, published by the Government of Indonesia with support from the Food and Agricultural Organization and Norway's International Climate and Forest Initiative, states that orangutan populations (Pongo spp.) have increased by more than 10% in Indonesia from 2015 to 2017, exceeding the government target of an annual 2% population increase [1]. This assessment is in strong contrast with recent publications that showed that the Bornean orangutan (P. pygmaeus) lost more than 100,000 individuals in the past 16 years [2] and declined by at least 25% over the past 10 years [3]. Furthermore, recent work has also demonstrated that both Sumatran orangutans (P. abelii) and the recently described Tapanuli orangutan (P. tapanuliensis) lost more than 60% of their key habitats between 1985 and 2007, and ongoing land use changes are expected to result in an 11-27% decline in their populations by 2020 [4,5]. Most scientific data indicate that the survival of these species continues to be seriously threatened by deforestation and killing [4,6,7] and thus all three are Critically Endangered under the International Union for Conservation of Nature's Red List.
    Matched MeSH terms: Pongo pygmaeus
  12. Nasution A, Perwitasari-Farajallah D, Utami-Atmoko SS
    Trop Life Sci Res, 2018 Jul;29(2):77-87.
    PMID: 30112142 DOI: 10.21315/tlsr2018.29.2.6
    Habitat loss and hunting are major threats to the long-term survival of the viable orangutan population in Batang Toru. East Batang Toru Forest Block (EBTFB) is the most threatened area due to low forest cover and high encroachment. Based on a preliminary survey in 2008, Hopong forest which is located in EBTFB, had the highest orangutan density (0.7 ind/km2). However illegal logging and hunting of protected species were occuring in this unprotected forest. Since this location has been gazetted as unprotected forest from the first survey until this study was conducted, it is important to assess orangutans population trends. This study aims to provide an updated density of orangutan in Hopong forest. The study included the location of the original survey but covered a wider overall area. The line transect method was used to record orangutan nests, ficus and trees bearing fruits. A quadrat method was used to record vegetation. The encounter rate of orangutan declined from 0.7 ind/km2 to 0.4 ind/km2 between 2008 and 2015. Forest cover has also changed in the seven years between surveys and this has influenced orangutan and orangutan nest encounter rates in Hopong. Since unprotected forest is at more risk in comparison with protected forest, allocation status of the Hopong forest is critical to reduce the threats it faces.
    Matched MeSH terms: Pongo pygmaeus
  13. Spehar SN, Sheil D, Harrison T, Louys J, Ancrenaz M, Marshall AJ, et al.
    Sci Adv, 2018 06;4(6):e1701422.
    PMID: 29963619 DOI: 10.1126/sciadv.1701422
    Conservation benefits from understanding how adaptability and threat interact to determine a taxon's vulnerability. Recognizing how interactions with humans have shaped taxa such as the critically endangered orangutan (Pongo spp.) offers insights into this relationship. Orangutans are viewed as icons of wild nature, and most efforts to prevent their extinction have focused on protecting minimally disturbed habitat, with limited success. We synthesize fossil, archeological, genetic, and behavioral evidence to demonstrate that at least 70,000 years of human influence have shaped orangutan distribution, abundance, and ecology and will likely continue to do so in the future. Our findings indicate that orangutans are vulnerable to hunting but appear flexible in response to some other human activities. This highlights the need for a multifaceted, landscape-level approach to orangutan conservation that leverages sound policy and cooperation among government, private sector, and community stakeholders to prevent hunting, mitigate human-orangutan conflict, and preserve and reconnect remaining natural forests. Broad cooperation can be encouraged through incentives and strategies that focus on the common interests and concerns of different stakeholders. Orangutans provide an illustrative example of how acknowledging the long and pervasive influence of humans can improve strategies to preserve biodiversity in the Anthropocene.
    Matched MeSH terms: Pongo pygmaeus
  14. Voigt M, Wich SA, Ancrenaz M, Meijaard E, Abram N, Banes GL, et al.
    Curr Biol, 2018 03 05;28(5):761-769.e5.
    PMID: 29456144 DOI: 10.1016/j.cub.2018.01.053
    Unsustainable exploitation of natural resources is increasingly affecting the highly biodiverse tropics [1, 2]. Although rapid developments in remote sensing technology have permitted more precise estimates of land-cover change over large spatial scales [3-5], our knowledge about the effects of these changes on wildlife is much more sparse [6, 7]. Here we use field survey data, predictive density distribution modeling, and remote sensing to investigate the impact of resource use and land-use changes on the density distribution of Bornean orangutans (Pongo pygmaeus). Our models indicate that between 1999 and 2015, half of the orangutan population was affected by logging, deforestation, or industrialized plantations. Although land clearance caused the most dramatic rates of decline, it accounted for only a small proportion of the total loss. A much larger number of orangutans were lost in selectively logged and primary forests, where rates of decline were less precipitous, but where far more orangutans are found. This suggests that further drivers, independent of land-use change, contribute to orangutan loss. This finding is consistent with studies reporting hunting as a major cause in orangutan decline [8-10]. Our predictions of orangutan abundance loss across Borneo suggest that the population decreased by more than 100,000 individuals, corroborating recent estimates of decline [11]. Practical solutions to prevent future orangutan decline can only be realized by addressing its complex causes in a holistic manner across political and societal sectors, such as in land-use planning, resource exploitation, infrastructure development, and education, and by increasing long-term sustainability [12]. VIDEO ABSTRACT.
    Matched MeSH terms: Pongo pygmaeus/physiology*
  15. Tajima T, Malim TP, Inoue E
    Primates, 2018 Mar;59(2):127-133.
    PMID: 29387973 DOI: 10.1007/s10329-017-0648-1
    The reproductive success of male primates is not always associated with dominance status. For example, even though male orangutans exhibit intra-sexual dimorphism and clear dominance relationships exist among males, previous studies have reported that both morphs are able to sire offspring. The present study aimed to compare the reproductive success of two male morphs, and to determine whether unflanged males sired offspring in a free-ranging population of Bornean orangutans, using 12 microsatellite loci to determine the paternity of eight infants. A single flanged male sired most of the offspring from parous females, and an unflanged male sired a firstborn. This is consistent with our observation that the dominant flanged male showed little interest in nulliparous females, whereas the unflanged males frequently mated with them. This suggests that the dominant flanged male monopolizes the fertilization of parous females and that unflanged males take advantage of any mating opportunities that arise in the absence of the flanged male, even though the conception probability of nulliparous females is relatively low.
    Matched MeSH terms: Pongo pygmaeus/classification; Pongo pygmaeus/genetics; Pongo pygmaeus/physiology*
  16. Hayashi M, Kawakami F, Roslan R, Hapiszudin NM, Dharmalingam S
    Primates, 2018 Mar;59(2):135-144.
    PMID: 29383576 DOI: 10.1007/s10329-018-0650-2
    The Bukit Merah Orang Utan Island (OUI) Foundation has been conducting behavioral and veterinary research on orangutans as an attempt at ex situ conservation. Since 2010, the Primate Research Institute, Kyoto University has been collaborating with OUI to promote environmental enrichment and infant rearing by biological mothers in addition to the continuous efforts of refining the veterinary management of the endangered species. In 2011, three Bornean orangutans (Pongo pygmaeus pygmaeus) were released on an island, called BJ Island, adjacent to OUI. This island is approximately 5.6 ha in size, and 635 trees belonging to 102 plant species were identified prior to their release. Behavioral monitoring of the released individuals has been conducted to evaluate their behavioral adaptation to the new environment. Two of the three released orangutans were born in the wild, whereas the youngest individual was born on OUI and expected to learn forest survival strategies from the two older individuals. One of the orangutans was pregnant at the time of release and subsequently gave birth to two male infants on BJ Island. The behavioral monitoring indicated that these orangutans traveled more and spent more time on trees following their release onto BJ Island. However, resting was longer for two females both on OUI and BJ Island when compared to other populations. The orangutans consumed some natural food resources on BJ Island. The release into a more naturalistic environment may help the orangutans to develop more naturalistic behavioral patterns that resemble their wild counterparts.
    Matched MeSH terms: Pongo pygmaeus/physiology*
  17. Nater A, Mattle-Greminger MP, Nurcahyo A, Nowak MG, de Manuel M, Desai T, et al.
    Curr Biol, 2017 Nov 20;27(22):3487-3498.e10.
    PMID: 29103940 DOI: 10.1016/j.cub.2017.09.047
    Six extant species of non-human great apes are currently recognized: Sumatran and Bornean orangutans, eastern and western gorillas, and chimpanzees and bonobos [1]. However, large gaps remain in our knowledge of fine-scale variation in hominoid morphology, behavior, and genetics, and aspects of great ape taxonomy remain in flux. This is particularly true for orangutans (genus: Pongo), the only Asian great apes and phylogenetically our most distant relatives among extant hominids [1]. Designation of Bornean and Sumatran orangutans, P. pygmaeus (Linnaeus 1760) and P. abelii (Lesson 1827), as distinct species occurred in 2001 [1, 2]. Here, we show that an isolated population from Batang Toru, at the southernmost range limit of extant Sumatran orangutans south of Lake Toba, is distinct from other northern Sumatran and Bornean populations. By comparing cranio-mandibular and dental characters of an orangutan killed in a human-animal conflict to those of 33 adult male orangutans of a similar developmental stage, we found consistent differences between the Batang Toru individual and other extant Ponginae. Our analyses of 37 orangutan genomes provided a second line of evidence. Model-based approaches revealed that the deepest split in the evolutionary history of extant orangutans occurred ∼3.38 mya between the Batang Toru population and those to the north of Lake Toba, whereas both currently recognized species separated much later, about 674 kya. Our combined analyses support a new classification of orangutans into three extant species. The new species, Pongo tapanuliensis, encompasses the Batang Toru population, of which fewer than 800 individuals survive. VIDEO ABSTRACT.
    Matched MeSH terms: Pongo pygmaeus/genetics
  18. Davies AB, Ancrenaz M, Oram F, Asner GP
    Proc Natl Acad Sci U S A, 2017 Aug 01;114(31):8307-8312.
    PMID: 28720703 DOI: 10.1073/pnas.1706780114
    The conservation of charismatic and functionally important large species is becoming increasingly difficult. Anthropogenic pressures continue to squeeze available habitat and force animals into degraded and disturbed areas. Ensuring the long-term survival of these species requires a well-developed understanding of how animals use these new landscapes to inform conservation and habitat restoration efforts. We combined 3 y of highly detailed visual observations of Bornean orangutans with high-resolution airborne remote sensing (Light Detection and Ranging) to understand orangutan movement in disturbed and fragmented forests of Malaysian Borneo. Structural attributes of the upper forest canopy were the dominant determinant of orangutan movement among all age and sex classes, with orangutans more likely to move in directions of increased canopy closure, tall trees, and uniform height, as well as avoiding canopy gaps and moving toward emergent crowns. In contrast, canopy vertical complexity (canopy layering and shape) did not affect movement. Our results suggest that although orangutans do make use of disturbed forest, they select certain canopy attributes within these forests, indicating that not all disturbed or degraded forest is of equal value for the long-term sustainability of orangutan populations. Although the value of disturbed habitats needs to be recognized in conservation plans for wide-ranging, large-bodied species, minimal ecological requirements within these habitats also need to be understood and considered if long-term population viability is to be realized.
    Matched MeSH terms: Pongo pygmaeus
  19. Santika T, Ancrenaz M, Wilson KA, Spehar S, Abram N, Banes GL, et al.
    Sci Rep, 2017 07 07;7(1):4839.
    PMID: 28687788 DOI: 10.1038/s41598-017-04435-9
    For many threatened species the rate and drivers of population decline are difficult to assess accurately: species' surveys are typically restricted to small geographic areas, are conducted over short time periods, and employ a wide range of survey protocols. We addressed methodological challenges for assessing change in the abundance of an endangered species. We applied novel methods for integrating field and interview survey data for the critically endangered Bornean orangutan (Pongo pygmaeus), allowing a deeper understanding of the species' persistence through time. Our analysis revealed that Bornean orangutan populations have declined at a rate of 25% over the last 10 years. Survival rates of the species are lowest in areas with intermediate rainfall, where complex interrelations between soil fertility, agricultural productivity, and human settlement patterns influence persistence. These areas also have highest threats from human-wildlife conflict. Survival rates are further positively associated with forest extent, but are lower in areas where surrounding forest has been recently converted to industrial agriculture. Our study highlights the urgency of determining specific management interventions needed in different locations to counter the trend of decline and its associated drivers.
    Matched MeSH terms: Pongo pygmaeus/growth & development*
Filters
Contact Us

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links