Primate Action Blog
  • Primate Conservation Inc. - All the World's Primates Book Giveaway to Habitat Country NGOs


    A generous donor to Primate Conservation, Inc. (PCI) has offered to subsidize the purchase and distribution of a number of All the World’s Primates books to primate habitat country conservation organizations. If you are a member of one of these organizations and could use copies of this book (for a description go to, please answer the following questions and send your information to Noel Rowe at

    Your organization's name, mailing address, and email.

    Name and CV of a principal in your organization.

    Date your organization was founded.

    URL of your website, if any.

    Are you affiliated with or primarily supported by a larger organization?

    Is your annual budget under $10,000 US, $10,000 to $100,000 US, or over $100,000?

    How many books would you like (up to 3, which can be mailed in one box)

    What primates does your organization work to protect?

    In 500 words or less, how will the book(s) be used by your organization?

    Please, do not include any information as attachments. Only material in the body of the email will be considered. The decision about which organizations will be awarded these books is up to the donor and the Board of Directors of PCI. Submissions must be made no later than August 10, 2017. Only winners will be notified. We will not share any of your information with others. You may get an annual email from PCI.

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  • Free Download: Lemurs of Ranomafana


    All The World’s Primates is sharing a free ebook, The Lemurs of Ranomafana. Created for the participants in the recent Prosimian Congress in Ranomafana National Park, Madagascar (August 2013), we thought others might like it. It’s available as either a mobi file (for Kindle) or epub for iPad, tablet, smart phone or other reader. Download link below.

    The Lemurs of Ranomafana is adapted from Pogonias Press’ new ebook  All the World’s Lemurs, Lorises, Bushbabies, and Pottos (Amazon $9.95). Planned as the first volume in a series, it illustrates the diversity of the fascinating suborder Strepsirhini, a group which contains many of our oddest, rarest, most beautiful, and least-known primate relatives. More than 100 photographers and primatologists who contributed to this website were involved.

    All the World’s Lemurs, Lorises, Bushbabies, and Pottos is a portable resource to help to introduce you to this fascinating group of primates. It has general information about each super family and family followed by profiles of 134 species. Every species profile includes a color photograph or illustration, a color range map, and information on the species’ taxonomy, distinguishing characteristics, physical characteristics, locomotion, diet, life history, social organization, behavior, habitat, IUCN conservation status, and threats the species faces in its natural habitat. The information is fully referenced (Lemurs of Ranomafana is not). Get the ebooks:

    All the World’s Lemurs, Lorises, Bushbabies, and Pottos is available at Amazon. $9.95

    The Lemurs of Ranomafana is available, free here.

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  • Three New Species of the Masked Slow Loris are Newly Recognized

      Kayan Slow Loris is new to science
    photo courtesy Chien C. Lee,

    By R. Munds, S. Ford & K.A.I. Nekaris

    An international team of scientists studying the elusive nocturnal primate the slow loris in the jungles of Borneo have discovered an entirely new species. The team’s analysis of the primate’s distinctive facial fur markings, published in the American Journal of Primatology, reveals the existence of one entirely new species, while two of species, previously considered as possible sub-species, are being officially recognized as unique.

    “Technological advances have improved our knowledge about the diversity of several nocturnal mammals,” said Rachel Munds from the University of Missouri Columbia. “Historically many species went unrecognized as they were falsely lumped together as one species. While the number of recognized primate species has doubled in the past 25 years some nocturnal species remain hidden to science.” The slow loris (Nycticebus) is found across South East Asia, from Bangladesh and China’s Yunnan province to the island of Borneo, the slow loris is rare amongst primates for having a toxic bite, and is rated as Vulnerable or Endangered on the IUCN Red List. Slow lorises are recognized by their unique fur coloration on the body and face, yet while traits such as fur patterns are often used to distinguish between species; nocturnal species are cryptic in coloration and have less obvious external differences. The team’s research focused on the distinctive colorings of Borneo’s slow loris, whose faces have an appearance of a mask, with the eyes being covered by distinct patches and their heads having varying shapes of caps on the top. Differences among these face masks resulted in recognition of four species of Bornean and Philippine lorises, N menagensis, N. bancanus, N. borneanus and N. kayan. Of these Nycticebus kayan is a new group unrecognized before as distinct. This new species is found in the central-east highland area of Borneo and is named for a major river flowing in its region, the Kayan.

    The recognition of these new species strongly suggests that there is more diversity yet to be discovered in the jungles of Borneo and on the surrounding islands, including the Philippines. However, much of this territory is threatened by human activity so the possibility that more slow loris species exist in small and fragile ranges raises urgent questions for conservation efforts.

    “The pet trade is a serious threat for slow lorises in Indonesia, and recognition of these new species raises issues regarding where to release confiscated Bornean slow lorises, as recognition by non-experts can be difficult,” said co-author Professor Nekaris, from Oxford Brookes University.

    “In the first study to quantify facial mask differences we have recognized three new species of slow loris, two of which were recognized as subspecies at some point in the past, but are now elevated to species status, and one previously unrecognized group.” concluded Ms. Munds. “This finding will assist in conservation efforts for these enigmatic primates, although survey work in Borneo suggests the new species are either very difficult to locate or that their numbers may be quite small.”

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  • Unmanned Drones Used to Count Orangutan Nests

      Lian Pin Koh and Serge Wich with drone
    photo courtesy conservationdrones

    Note that this post is a departure as the project is not presently supported by Primate Conservation, Inc. (PCI). This technology has potential in conserving primates and so is presented here. Dr. Wich is a contributor to All The World’s Primates for orangutans and Thomas’ Langur. He has also reviewed proposals on PCI’s behalf.

    Adapted from an article by Lian Pin Koh (ETH Zurich) and Serge Wich (Liverpool John Moores University) for the Orangutan Conservancy

    The distribution and density of orangutan nests, critical to conservation efforts, have traditionally been obtained by costly and time consuming ground surveys. High resolution satellite imagery that might serve the same purpose has been too costly or simply unavailable.

    But Researchers Lian Pin Koh and Serge Wich proposed what seemed at first to be a wild idea: conservation drones. The researchers have tested the conservation drones above orangutan habitat in Sumatra and Sabah (Borneo). The aim of these tests was to determine whether the system could really detect orangutan’s nests. The results are in and it can!

    Conservation Drones are inexpensive, autonomous and operator-friendly unmanned aerial vehicles for surveying and mapping forests and biodiversity. They are able to fly pre-programmed missions autonomously for a total flight time of up to ~50 minutes and over a distance of ~25 km. Depending on the camera system installed, these drones can record videos at up to 1080 pixel resolution, and acquire aerial photographs of <10 cm pixel resolution. Aerial photographs can be stitched together to produce near real-time geo-referenced land use/cover maps of surveyed areas.

    In addition the images from the drone are of a high enough resolution that one can easily distinguish land cover and land use including forests, corn fields, plantations, logging, fires, small roads, mining, banana plantings, etc. The drone approach therefore seems extremely promising as a tool in orangutan conservation and we look forward developing this further in close collaboration with our partners.

      detail of an orangutan nest as seen from the air
    photo courtesy conservationdrones

    Although Wich and Koh conceived of the idea of the conservation drone while discussing orangutan research and conservation, the drones are now being tested in various countries for a whole range of projects. As Dr. Wich explains, “A main aim of our work is to share our knowledge for building low-cost Conservation Drones to help conservation workers and researchers in developing countries do their jobs a lot more effectively and cost efficiently.” Visit the Conservation Drone Project website for more details on this high-flying project. Details from the Orangutan Conservancy here.

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  • Evaluation Begun on the Role Rare and Recently Recognized Gibbons Play in Their Environment

      The northern buff-cheeked gibbon (Nomascus annamensis)
    was first described in 2010. Photo by Jackson Frechette

    Jackson Frechette and Kathryn Sieving

    Since June, I [Jackson] have been working on my dissertation project, “The effects of crested gibbon (Nomascus annamensis) seed dispersal patterns on tree regeneration,” in the Veun Sai–Siem Pang Conservation Area, 55,000 ha managed by Conservation International and the Cambodian Forestry Administration in a remote part of northeastern Cambodia. I have been working with local ethnic minority researchers and one American volunteer (who hopes to go to graduate school) to understand the importance of northern buffed-cheek crested gibbons to trees. This is a new gibbon species that was described in 2010 using acoustic and genetic data. I am looking at seed dispersal patterns of these gibbons and how those patterns may be important for trees to regenerate. To do this, I quantified the gibbon seed dispersal pattern by mapping where every seed of a particular tree (Microcos paniculata) was defecated. Then, using that pattern, I planted 9,000 seeds of that tree, mimicking the gibbon pattern, a bird dispersal pattern (which I quantified as well), and a pattern where all the seeds just fall beneath the fruiting trees. The purpose of this is to test if there is a difference in seed germination between these dispersal patterns.

    This research explicitly tests the often theorized impact one primate species has on the patterns of seed dispersal and seed survival in its environment. The results will provide information on the importance of this endangered gibbon to tree regeneration and ecosystem health. I have been training local people on how to conduct research and to be interpretive guides for gibbon-centered community-based tourism. Increasing the local capacity develops sustainable alternatives to hunting and logging, reducing pressure on the community’s natural resources.

      Jackson (on the far left) with his team in Cambodia.
    Photo by Cheb Chanton-CI Staff

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  • Survey Locates Critically Endangered Tonkin Snub-nosed Monkey in Vietnam

        Tonkin Snub-Nosed Monkeys  
      Tonkin snub-nosed monkeys
    (Rhinopithecus avunculus)

    Adapted from the report of
    Thach Mai Hoang,
    HUS, Vietnam National University - Hanoi

    Two years of intensive surveys have confirmed the continued existence of one of the world's rarest primates in the forests of the Na Hang Nature Reserve, Vietnam. Once thought extinct, the Tonkin snub-nosed monkey (Rhinopithecus avunculus Dollman, 1912) was rediscovered in the late 1980's in two adjacent forests about 250 kilometers north of Hanoi. But despite action by the Vietnamese government establishing these forests as nature reserves and conservation efforts by multiple NGOs including Primate Conservation, the construction of a hydroelectric dam in the midst of their range at the beginning of this century appeared to have sealed their fate. Surveys since construction had reported no snub-nosed for several years and many thought them to locally be extinct.

    Outside Na Hang Nature Reserve the world population of the Tonkin snub-nosed monkey is thought to be much less and 100 individuals so the Na Hang Reserve is of the highest importance to its survival. Despite this, conservation efforts had faltered because of the lack of snub-nosed sitings. Our recent field surveys, training and conservation work is an attempt to re-energize efforts in the Reserve.

    The project began in 2009 and focused mainly on field work to determine if the snub-nosed monkeys remained in the forests surrounding Na Hang. In the long first year no R. avunculus were seen. Work was redoubled in 2010. Most important, the active cooperation of the Peoples' Resource and Conservation Foundation (PRCF) and Tuyen Quang Forestry Protection Department’s (FPD) Conservation Division allowed us to stay longer in the field and attract more participation by forest rangers and community members.


      An adult Tonkin snub-nosed monkey leaping up
    in the Ban Bung Sector 31st October, 2010.
    It’s head is obscured by foliage.
    (Photo by Thach Mai Hoang)

      An adult Tonkin snub-nosed monkey looking at observer
    from about 200 – 250 meters on 1st November, 2010.
    (Photo by Hoang Trung Thanh)
      Hunting rifle confiscated in Khau Tep Area, Tat Ke Sector 

    Then on 29th September, 2010 at 12:10 PM in Tat Ke Sector, we saw our first group of Tonkin snub-nosed monkeys. The local guide Quan Van Thiet, observed five animals including two adult males, three adult females and more animals behind dense foliage. This group likey  consists of two subgroups because two adult males were observed. If the subgroups have the same organization with an average size of 4-5 adults in a One-Male-Unit pattern, the number of individuals may be ten (or more).

    Subsequently, three groups of Tonkin snub-nosed monkeys were observed in the Ban Bung Sector. The first group with a maximum of ten individuals including at least one infant was observed on four occasions. On two of those occasions the group was seen  foraging in association with a group of 20-25 stump-tailed macaques (Maccaca arctoides), the first time this behavior has been documented. The second Ban Bung group of Tonkin snub-nosed monkey was detected by vocalization in Pa Puc Area by a survey party on 2nd November, 2010 at 12:06 p.m. According to our estimates this group has from two to four individuals. A local guide, Nong Van Huan, observed two adults at 5:30 p.m. on 7th November, 2010. He thought that it was the same group we encountered on 2nd November but they were observed after five days at at second location so may represent a third group.

    The field surveys in Tat Ke and Ban Bung Sector covered most of the potential habitats for Tonkin snub-nosed monkey. Risks to the animal are still considered great. Hunting stands out as the most serious threat in both sectors. During our survey in Tat Ke Sector, forest rangers confiscated one rifle from a local hunter. Photos and the coordinates of timber extraction sites and hunter campsites were recorded and reported to the Forestry Department. Habitat destruction was the second largest risk and is more severe in Ban Bung Sector than in Tat Ke. Lack of enforcement personnel is also a difficulty. The new hydropower dam has increased accessibility to the Nature Reserve creating another obstacle for forest protection. To date, one floating ranger station on the Gam River and another on the Nang River have been established to control the access by river.

    To maximize the effectiveness of existing staff, we provided a technical training course for rangers and Community Patrol members of Na Hang Nature Reserve. Local forest rangers and CPG members were trained on conservation status and survey techniques for the Tonkin snub-nosed monkey. There was also training in the use of map, GPS, compass, records keeping and interview skills. Threats to TSNM and biodiversity of Na Hang Nature Reserve were discussed extensively to strengthen awareness of conservation for forest rangers and Community Patrol members.


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  • Survey of the Habitat of Rare Bolivian Monkeys Aids the Establishment of a Municipal Reserve

        Lesley Lopez and Ariel Reinaga Class about Environmental Conservation
      Heidy Lopez-Strauss and Jesus Martinez at a school teaching
    a class about environmental conservation.
    (Photo by WCS)

    Jesus Martinez, Heidy Lopez-Strauss and Robert Wallace

    Between 2004 and 2010, with funding from PCI and the Wildlife Conservation Society, we documented the distribution of the two titi monkeys (Callicebus) in the central and western parts of the Beni Department in Bolivia. Living only in Bolivia, these titis both have extremely restricted ranges. The information was provided to local authorities, helping to establish a Municipal Reserve in the Santa Rosa del Yacuma Municipality. This important conservation initiative protects both titi monkeys, encompassing the majority of their distribution.

    Olalla Brothers’ titi (Callicebus olallae) has the most restricted distribution, limited to the southwestern part of Beni Department with a range of only 5000 hectares. Beni titi monkey (C. modestus) has a slightly larger distribution with an occupancy area of 45,000 hectares. Several research projects have been simultaneously conducted, to learn about diet, demography and population abundance of both species. We determined that C. olallae forms groups of on average two individuals, and we estimate that the maximum population is only 1,927 individuals. For C. modestus each group is formed by an average of 2.64 individuals, with a maximum number of 20,072 individuals. Diet and behavior studies are currently being analyzed for publication in 2012. With the information gathered, we had enough evidence to determine the IUCN threat category of “Endangered” for both species.

    The challenges we face now are 1) to provide help with the development of a management plan for the reserve, and the extent of the main threats facing the monkeys 2) to learn how the species are responding to increasing threats in the region and establish environmental monitoring programs, and 3) to develop locally appropriate outreach and environmental education activities. Current support from PCI is allowing us to assess the historical and current deforestation, and begin to plan appropriate conservation actions including coordination with the Bolivian road authorities which are planning a new road in the middle of the ranges of the titis.

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  • World Population of the Endangered Western Hoolock Gibbons Now Less than Previously Thought

    Eastern Hoolock Gibbon Female
      Eastern hoolock gibbon female
    (Hoolock leuconedys)

    Rekha Chetry Ph.D and Dilip Chetry,Ph.D

    The endangered western hoolock gibbon's (Hoolock hoolock) world population is now less than previously estimated. This lesser ape and close relative to man, known for its beautiful songs, was thought to be the only gibbon in Assam, India. Assam was thought to be one of the few places where it still had a viable population.

    We surveyed six forest reserves in Sadiya, a part of Tinsukia district on the extreme east boundary of Assam. Instead of the western hoolock, we determined that the gibbon population is the vulnerable eastern gibbon (Hoolock leuconedys). A total of 33 individuals in 10 groups were recorded from direct sighting. We estimate the occurrence of another 16 groups from calls counted. The average group size was 3 with individuals ranging from 1 to 5. Sadly our survey found no gibbons present in 3 of the 6 forest reserves.

    And these eastern hoolocks are under threat. The reserves, unlike a sanctuary or national park, do not enjoy strong legal protection and face numerous threats, including hunting, illegal logging, commercial harvesting of bamboo, cane, ferns, tora, and cattle grazing. Almost half of the forest reserve land is under encroachment with 6070 hectares out of 12,512 lost. This is due to a lack of community awareness and inadequate protection. The forest department has a staff of only 8 people to combat illegal activities and there are no staff quarters or offices in any of the reserves.

    We initiated the first education and awareness program and our new findings received wide media coverage. We plan to recommend that the 3 reserve forests become wildlife sanctuaries with the eastern hoolock gibbon as a flagship species for conservation.

    Rehka Chetry (wearing cap) with her survey team


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  • The First Study of the Bale monkey, a Species Unique to the Central Mountains of Ethiopia

       Juvenile Bale Monkey
      Juvenile Bale Monkey

    Addisu Mekonnen and Anagaw Atickem

    Bale monkey (Chlorocebus djamdjamensis) is an Old world monkey endemic to the Bale Mountains of Ethiopia. Discovered in 1902, little was known about the ecology and distribution of the species. Our PCI funded research aims to provide reliable data on the distribution and basic ecology of the species vital for conservation efforts. We began by using high resolution satellite images to find potential sites for the Bale monkey survey. This lead to the discovery of three new Bale monkey populations.

    The results of our research show that the Bale monkey is found exclusively in the bamboo forest. Bale monkeys feed on 11 plant species but bamboo compromises about 77% of their diet. They consumed mainly bamboo young leaves. Thus, bamboo is a key resource for the species. This is especially surprising given that all of their close relatives including vervet monkeys and green monkeys are very adaptable generalists who eat diverse, varied diets and occupy a wide variety of habitats. This habitat specialist behavior of the Bale monkey on bamboo forest makes the species vulnerable.

      Omer Hajeleye (left, villager) and
    Addisu Mekonnen (right, principal investigator) in
    the Odobullu Forest of Ethiopia
    The amount of bamboo forest is small and it is cut by local people. Currently, we are continuing to survey for Bale monkey populations in Sidamo highlands areas, south west of Bale Mountains. Additionally, we are collaborating with the University of Oslo to determine the genetics of this taxon. We strongly recommended a conservation action plan be developed for all the Bale monkey populations.


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  • Conservation Implications of Hybridization Between Two Species of Brown Lemur

       Kira Delmore with 2 Red Fronted Lemurs
      Kira Delmore with 2 red fronted lemurs
    she captured and released. (Photo by Margaux Keller)

    Kira Delmore

    Hybridization, interbreeding between individuals from distinct populations or species, can be either a risk or a benefit to the survival of rare animals. Uncommon species may be overwhelmed by the gene flow from a more abundant animal and the offspring of such pairings runs the risk the of sterile children. But hybridization also serves as a conservation opportunity by introducing variation into a rare animal's gene pool. Variation is important for the survival and adaptability. If a species’ environment changes, the possession of variation will enable it to adapt and compete successfully in their new environment.

    We evaluated these two possibilities in a hybrid zone between the red-fronted lemur (Eulemur rufifrons) and the gray headed (E. albocollaris). The red-fronted lemur has a large range; it can be found in both western dry forests and eastern rainforests. The gray-headed lemur has a much more restricted range; it consists of only two isolated populations on the southeastern coast which suffer from fragmentation and hunting. The gray-headed lemur is currently listed as endangered on the IUCN Red List and considered one of IUCN’s Top 25 most endangered primates in the world.

    We established 18 sampling sites along transects through the hybrid zone. We captured a minimum of 10 individuals at each site, measured them for standard morphological variables and obtained blood samples for genetic analyses. Results from our analyses suggest that hybridization between red-fronted and gray-headed lemurs is serving as a conservation opportunity. First, there was no evidence of unidirectional gene flow (i.e., the gray-headed lemur is not being swamped by gene flow from the red-fronted lemur). Second, hybrids appear to be equally as fit as parental forms and exhibit unique traits (e.g., longer tails), suggesting that hybrid populations are isolated from the other two species. These findings suggest that evolution restricted to hybrids may be occurring. The remaining forest in the hybrid zone’s range is currently threatened of slash-and-burn agriculture, small-scale mining, logging, hunting and trapping. Given the potential for evolutionary innovation in this hybrid zone and its function as a conservation opportunity for gray-headed lemurs, we encourage the protection of the Andringitra region and its corridors.


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