Gorilla gorilla

Assessment Information: Justification: Gorilla gorillahas a large geographic range, covering over 700,000 km². The size of the population is currently being evaluated, but thought to be in the order of a few hundred thousand (Strindberg et al. in prep). Only a very small number of Western Gorillas are the G. g. diehli subspecies, therefore this rationale focuses on the G. g. gorilla subspecies. The country of Gabon lost over half its Gorilla population between 1983 and 2000 (Walsh et al. 2003). More recent population declines have been estimated using a predictive model that incorporated survey data collected between 2003 and 2013 across the entire range of Western Lowland Gorillas. The results reveal an 18.75% decline between 2005 and 2013, corresponding to an annual loss of ~2.56% (Strindberg et al. in prep). These population decreases were driven by poaching and disease (Ebolavirus) outbreaks.Despite their abundance and wide geographic range, Western Gorillas qualify as Critically Endangered under criterion A: a population reduction of more than 80% over three generations (one generation is ~22 years). This listing is based on ongoing population losses due to illegal hunting, disease and habitat loss: poaching is intensifying with the expansion of access routes into forests and Zaire Ebolavirus remains a highly significant threat. At a conservative rate of reduction (2.56% per year rather than 4%, calculated from Walsh et al. 2003), the reduction in the Western Gorilla population is predicted to exceed 80% over three generations (i.e., 66 years, 2005-2071). Illegal hunting has not ceased despite intense anti-poaching efforts, and the threat of Ebolavirus has not been removed. In addition, the scale of habitat conversion to industrial agriculture will increase, and the effects of climate change will become more evident.Gorilla gorillathus qualifies as Critically Endangered (A4bcde)

Lignes directrices pour de meilleures pratiques en matière d’inventaire et de suivi des populations de grands singes

From Executive Summary: The combination of threats currently facing the remaining great apes requires immediate conservation action at all scales — from site-level initiatives, through national and regional strategies, to international conventions and action plans. Baseline density estimates and subsequent monitoring of ape populations are essential for assessing the impacts of particular threats and measuring whether conservation programmes are succeeding.  Available at: https://portals.iucn.org/library/node/922

Ape Population Abundance Estimates

This annex presents ape abundance estimates at the site level. The term “site” refers to a protected area and its buffer zone, a logging concession or group of concessions, or any discrete area where a survey has taken place in the past two decades, although this annex also lists a few sites that were last surveyed in the 1970s and 1980s.Output Type: Online-only anne

Pan troglodytes (errata version published in 2018)

Assessment Information: Although Pan troglodytes is the most abundant and widespread of the great apes, and many populations exist in protected areas, the declines that have occurred are expected to continue, satisfying the criteria for an Endangered listing (Oates 2006). Due to high levels of poaching, infectious diseases, and loss of habitat and habitat quality caused by expanding human activities, this species is estimated to have experienced a significant population reduction in the past 20–30 years and it is suspected that this reduction will continue for the next 30–40 years. Due to their slow life history and a generation time estimated to be 25 years, Chimpanzee populations cannot sustain high levels of mortality, whether disease-induced or caused by poaching. The maximum population reduction over a three-generation (75 year) period from 1975 to 2050 is suspected to exceed 50%, hence qualifying this taxon as Endangered under criterion A. Although conservation efforts directed at Chimpanzees and other wildlife have increased significantly in recent years, the assumption that population reductions will continue is a precautionary approach based on the rapid growth of human populations in sub-Saharan Africa, continuing poaching for bushmeat, the commercial bushmeat trade, the arrival of industrial agriculture (which requires clearcutting of forest), corruption and lack of law enforcement, lack of capacity and resources, and political instability in some range states. At the same time, zoonosis and disease outbreaks present significant risks; there is, for example, evidence that Ebolavirus will continue to spreadin some parts of the Chimpanzee's geographic range(Walshet al.2005)

Best Practice Guidelines for Surveys and Monitoring of Great Ape Populations

First paragraph: Les menaces qui touchent aujourd'hui les grands singes appellent à des actions immédiates de conservation à tous les niveaux : initiatives locales, stratégies nationales et régionales, conventions internationales et plans d'action. Une estimation préalable de la densité des grands singes est nécessaire pour avoir une base de suivi des impacts de menaces spécifiques et pour évaluer le succès des programmes de conservation

Lignes directrices pour de meilleures pratiques en matiere d’inventaire et de suivi des populations de grands singes

First paragraph: Les menaces qui touchent aujourd'hui les grands singes appellent à des actions immédiates de conservation à tous les niveaux : initiatives locales, stratégies nationales et régionales, conventions internationales et plans d'action. Une estimation préalable de la densité des grands singes est nécessaire pour avoir une base de suivi des impacts de menaces spécifiques et pour évaluer le succès des programmes de conservation

Do primate action plans work?

John Oates authored the first primate conservation Action Plan in 1986, which assessed the status of and proposed conservation actions for all mainland African primate species. A revised version of the continent-wide plan was published in 1996, but since then, action plans have generally evolved into prioritizing actions for specific species, often within defined landscapes. We will review and evaluate the content and success of conservation action plans for the nine currently recognized taxa of chimpanzees and gorillas in Africa. Since 2003, six detailed action plans and one population viability analysis have been published, covering priority actions and landscapes for seven of the nine great ape taxa in Africa. Two further action plans (for gorillas and chimpanzees in Eastern DRC and for bonobos) are in the final stages of review and may also be included in the analysis. Assessments for western chimpanzees, Cross River gorillas, western lowland gorillas and central chimpanzees have been peer reviewed, and we will consider their recommendations and the challenges of quantitatively evaluating the success of primate conservation action plans

Les grands singes et le FSC: Mise en oeuvre de pratiques d’exploitation favorables aux grands singes dans les concessions forestières en Afrique centrale

La survie des grands singes est de plus en plus incertaine en Afrique. Plusieurs facteurs comme la chasse, la disparition des milieux naturels et les maladies infectieuses se conjuguent et entrainent une diminution spectaculaire des populations. Ce déclin se poursuit alors que les grands singes africains sont des espèces de préoccupation internationale pour la conservation et que des efforts concertés ont porté depuis les années 1980 sur la création de réseaux d'aires protégées, l'élaboration de plans d'action pour la conservation et l'établissement d'accords politiques. Selon les prévisions, les tendances actuelles se poursuivront en l'absence de mesures immédiates et majeures d'atténuation des menaces. La disparition d'une espèce de grands singes, quelle qu'elle soit, serait une immense perte en termes de biodiversité africaine, de rôle écologique et de notre patrimoine commun d'évolution

Great apes and FSC: Implementing 'ape friendly' practices in Central Africa's logging concessions

First paragraph: The long-term survival of Africa's great apes has become increasingly uncertain. Dramatic declines in their population numbers have resulted from a combination of factors, including hunting, habitat loss and infectious disease. Although African apes are species of international concern, and despite concerted efforts since the 1980s to create protected area networks, develop conservation action plans and establish policy agreements, their populations continue to decrease. Future projections indicate that this trend will continue unless significant measures to reduce existing threats are taken immediately. The permanent disappearance of any ape species from the wild would be a huge loss to African biodiversity, to the important ecological function they play, and to our shared evolutionary heritage.  Also available at: https://portals.iucn.org/library/node/1037