Mountain Gorillas of Rwanda Status Report

This study investigates potential toxic hazards in the environment surrounding Volcanoes National Park (VNP) in Rwanda, a habitat for endangered mountain gorillas. Data collected from local residents revealed four main categories of hazards: household chemicals, pharmaceutical products, agricultural pesticides, and poisonous plants. The findings highlight inadequate community awareness regarding these hazards and emphasize the need for education and proper disposal practices to mitigate risks to wildlife, especially in light of planned park expansion. The study underscores the importance of a One Health approach involving environmental, veterinary, and public health professionals to ensure the safety of wildlife and ecosystems.

This article explores the physical characteristics, social behavior, habitat, diet, threats, and conservation of Mountain gorillas (Gorilla beringei beringei). Endemic to the Albertine Rift montane forests in Africa, these endangered primates inhabit protected areas such as the Virunga Mountains and Bwindi Impenetrable National Park. With a population of approximately 1,063 individuals as of 2018, they are primarily herbivorous, highly social, and possess remarkable intelligence, sharing 98% of their DNA with humans. Threats include human encroachment, poaching, disease transmission from tourists, and political instability. Conservation efforts and eco-tourism, especially gorilla trekking in Rwanda, Uganda, and Congo, play vital roles in their survival. Despite their size, they are gentle giants, and observing them offers a unique and meaningful safari experience.

This article explores the physical characteristics, social behavior, habitat, diet, threats, and conservation of Mountain gorillas (Gorilla beringei beringei). Endemic to the Albertine Rift montane forests in Africa, these endangered primates inhabit high-altitude, misty forests within protected national parks in Rwanda, Uganda, and the Democratic Republic of Congo. With a population of approximately 1,063 individuals as of 2018, they are primarily herbivorous, social animals living in family groups led by a Silverback male. Despite their size and strength, they are gentle and shy, communicating through vocalizations, facial expressions, and body postures. Threats include human encroachment, poaching, habitat fragmentation, political instability, and disease transmission from humans. Conservation efforts and eco-tourism, such as gorilla trekking, are vital for their survival. Visiting these primates offers a unique opportunity to observe their behavior and support their preservation.

This doctoral dissertation investigates community conservation enterprises as a potential model for enhancing community livelihoods and conserving mountain gorillas within the Greater Virunga Transboundary Landscape. The study explores perceptions, behaviors, and the effectiveness of community-based tourism initiatives, analyzing their role in reducing illegal resource use and fostering sustainable conservation practices. Through qualitative and quantitative methods, the research assesses the impact of community enterprises on local communities and wildlife conservation, providing insights into strategies that promote community engagement, economic development, and biodiversity preservation in East Africa.

Cestodes of the family Anoplocephalidae parasitize a wide range of usually herbivorous hosts including rodents, ungulates, primates, elephants and hyraxes. While in some hosts, the epidemiology of the infection is well studied, information is lacking in others. This study of mountain gorillas in the Virunga Massif analyzed extensive samples including necropsies, fecal proglottids, and fecal samples from night nests and identified individuals. The dominant species detected was Anoplocephala gorillae, with only one individual hosting a Bertiella sp. Diagnostic tools such as microscopy and PCR assays were developed to distinguish between species based on egg morphology and genetic markers. Phylogenetic analyses confirmed the placement of A. gorillae within the genus Anoplocephala and revealed genetic diversity among isolates. The study found that A. gorillae is a common, apparently non-pathogenic parasite of mountain gorillas, with high prevalence across groups and significant intra-individual egg shedding fluctuation. Multiple samples are recommended for reliable detection, and fecal egg counts vary widely, indicating fluctuating infection intensity. The findings suggest that A. gorillae does not impair host health and that non-invasive fecal sampling is effective for monitoring parasite prevalence in wild populations.

The mountain gorilla population is critically small, with only about 1,000 individuals remaining, making them one of the most-endangered animals on earth. They live in a small forest that is surrounded by human development, among the highest density in Africa. Our trackers, researchers and anti-poaching teams are in the forest every day to protect, monitor and study the gorillas, as well as other biodiversity in the forest. Our community programs include initiatives on food and water security, livelihoods and education. They help lessen human reliance on the forest as a source of food or income, and help local communities thrive. Our programs reach some 30,000 people each year.

Increasing population density can increase infectious disease risk and thus reduce population growth and size. Host-parasite interactions of threatened animals that remain in small protected forest fragments therefore need to be monitored carefully. Due to extreme conservation efforts, the mountain gorilla (Gorilla beringei beringei) population in the 450-km2 Virunga Massif has more than doubled since 1973, reaching 604 individuals in 2016. To better understand changes in the transmission risks of soil-borne and other enteric pathogens for mountain gorillas, we determined defecation outputs of different age-sex classes and the diurnal variation in feces deposition. We weighed 399 wet fecal samples deposited at nest sites and on trails between nest sites by gorillas of varying age and sex, determined by lobe diameter, from five social groups (n = 58 gorillas) that range in the Volcanoes National Park, Rwanda. We found increasing daily average defecation outputs with increasing age-sex class (infants, 435 g; juveniles, 1346 g; medium-sized gorillas, 2446 g; silverbacks, 3609 g). Gorillas deposited two– to threefold the amount of feces at nest sites compared to on trails, suggesting that nest sites may function as hotspots for enteric pathogen infections through direct contact or when gorillas ingest foods contaminated with infectious larvae during site revisits in intervals matching the maturation period of environmentally transmitted gastrointestinal parasites. In combination with ranging and demographic data, these findings will enable the modeling of spatiotemporal variation in soil contamination and infectious disease risk for Virunga gorillas as their population density continues to increase.

The mountain gorilla (Gorilla beringei beringei) is one of two endangered subspecies of eastern gorilla. The principle approach to monitoring the two extant mountain gorilla populations has been to use fecal surveys to obtain DNA profiles for individuals that are then used for capture-recapture-based estimates of abundance. To date, 11 to 14 microsatellites have been used for this purpose. To adapt to ongoing changes in genotyping technologies and to facilitate the analysis of fecal DNA samples by multiple laboratories, we developed a panel of single nucleotide polymorphism (SNP) markers that can be used for future gorilla monitoring. We used published short read data sets for 3 individuals to develop a suite of 79 SNPs, including two sex markers, for a Fluidigm platform. This marker set provided high resolution to differentiate individuals and will facilitate future monitoring, leaving room for additional SNPs to be included in a 96-assay format.

The Virunga Massif mountain gorilla population has been periodically monitored since the early 1970s, with efforts increasing over time. The population declined drastically in the 1970s but stabilized in the 1980s and has since been steadily increasing within a limited habitat surrounded by dense human populations. This study examined fecal samples collected during the 2015–2016 surveys from both monitored and unmonitored gorilla groups to quantify strongylid and tapeworm infections using egg counts per gram. Results indicated that higher strongylid infections were associated with smaller habitat areas, higher gorilla densities, and environmental factors such as higher elevations, precipitation, and specific vegetation types. The impact of habituation was minor, affecting tapeworms only in interaction with environmental variables. The findings suggest that strongylid nematodes may partially regulate gorilla populations at higher densities. Conservation success has increased gorilla numbers but limited habitat expansion poses new health challenges, with environmental and host factors shaping helminth infection patterns. Further research is needed to understand the epidemiology and potential population regulation by helminths in this endangered species.

The world's 1063 mountain gorillas (Gorilla beringei beringei) live in two subpopulations at the borders of the Democratic Republic of Congo, Rwanda, and Uganda. The majority of mountain gorillas are human‐habituated to facilitate tourism and research, which brings mountain gorillas into close proximity of people daily. Wild great apes are proven to be susceptible to human pathogens, including viruses that have caused fatal respiratory disease in mountain gorillas (e.g., human metapneumovirus1). This is the result of the close genetic relatedness of humans and gorillas as species, and the structural and genetic similarity in molecular receptors that allow viruses to infect cells2. At the time of writing, there is no evidence that severe acute respiratory syndrome coronavirus 2, the coronavirus that causes coronavirus disease 19 (COVID‐19), has infected a mountain gorilla. However, due to the significant potential for human‐to‐gorilla transmission, mountain gorilla range States took immediate steps to minimize the COVID‐19 threat. These actions included a combination of preventive practice around gorillas and other great apes (e.g., mandatory face mask use, increased “social” minimum distancing from gorillas) as well as human public health measures (e.g., daily health/fever screenings, COVID‐19 screening, and quarantines). Minimization of the COVID‐19 threat also required socioeconomic decision‐making and political will, as all gorilla tourism was suspended by late March 2020 and guidelines developed for tourism reopening. A consortium that collaborates and coordinates on mountain gorilla management and conservation, working within an intergovernmental institutional framework, took a multifaceted One Health approach to address the COVID‐19 threat to mountain gorillas by developing a phased contingency plan for prevention and response. The aim of this paper is to describe how range States and partners achieved this collaborative planning effort, with intent that this real‐world experience will inform similar actions at other great ape sites.

This article explores the experience of gorilla tracking in Rwanda's Volcanoes National Park, highlighting the opportunities for close encounters with endangered mountain gorillas, the management and conservation efforts ensuring their protection, and the socio-economic benefits for local communities. It details the logistics of tracking permits, the habituation of gorilla families, and the significance of events like the Kwita Izina gorilla-naming ceremony. The piece also emphasizes the role of various conservation organizations working to preserve gorilla populations and promote sustainable tourism.

This document provides comprehensive information about gorilla trekking in East Africa, including what it entails, the best times to go, safety considerations, permit costs, necessary preparations, and guidelines for responsible behavior. It covers the locations where gorilla trekking is available, the threats faced by mountain gorillas, and additional insights into related wildlife experiences such as chimpanzee tracking and lowland gorillas. The FAQs aim to assist travelers in planning their gorilla trekking safari, ensuring a safe, respectful, and rewarding wildlife encounter while contributing to conservation efforts.

Conservation efforts have led to the recovery of the endangered mountain gorilla populations. Due to their limited potential for spatial expansion, population densities increased, which may alter the epidemiology of infectious diseases. Recently, clinical gastrointestinal illnesses linked to helminth infections have been recorded in both gorilla populations. To understand drivers and patterns of helminth infections we quantified strongylid and tapeworm infections across both Virunga Massif and Bwindi populations using fecal egg counts. We assessed the impact of age, sex, group size, season and spatial differences used as a proxy, which reflects observed variation in the occurrence of gastrointestinal problems, vegetation types, gorilla subpopulation growth and associated social structure on helminth infections. We revealed striking geographic differences in strongylid infections with higher egg counts mostly in areas with high occurrences of gastrointestinal disease. Increased helminth egg counts were also associated with decreasing group size in some areas. Observed spatial differences may reflect mutual effects of variations in subpopulation growth rates, gorilla social structure, and vegetation associated with altitude across mountain gorilla habitat. Helminth infection intensities in Virunga gorillas were lowest in the youngest and the oldest animals. Elucidating parasite infection patterns of endangered species with low genetic diversity is crucial for their conservation management.

Respiratory illness (RI) accounts for a large proportion of mortalities in mountain gorillas (Gorilla beringei beringei), and fatal outbreaks, including disease caused by human metapneumovirus (HMPV) infections, have heightened concern about the risk of human pathogen transmission to this endangered species, which is not only critically important to the biodiversity of its ecosystem but also to the economies of the surrounding human communities. Our goal was to conduct a molecular epidemiologic study to detect the presence of HRSV and HMPV in fecal samples from wild human-habituated free-ranging mountain gorillas in Rwanda and to evaluate the role of these viruses in RI outbreaks. Fecal samples were collected from gorillas with clinical signs of RI between June 2012 and February 2013 and tested by real-time and conventional polymerase chain reaction (PCR) assays; comparison fecal samples were obtained from gorillas without clinical signs of RI sampled during the 2010 Virunga gorilla population census. PCR assays detected HMPV and HRSV first in spiked samples; subsequently, HRSV-A, the worldwide-circulating ON1 genotype, was detected in 12 of 20 mountain gorilla fecal samples collected from gorillas with RI during outbreaks, but not in samples from animals without respiratory illness. Our findings confirmed that pathogenic human respiratory viruses are transmitted to gorillas and that they are repeatedly introduced into mountain gorilla populations from people, attesting to the need for stringent biosecurity measures for the protection of gorilla health.

The International Gorilla Conservation Programme (IGCP) has played a pivotal role in the protection and recovery of mountain gorillas over the past four decades. Originating from regional conservation efforts in Rwanda, IGCP evolved into a formal coalition of international organizations, expanding its scope across Rwanda, Uganda, and the Democratic Republic of Congo. The program has implemented anti-poaching measures, community engagement, habitat protection, and transboundary collaboration, resulting in significant population increases—census data indicate a rise to over 1,000 mountain gorillas globally. IGCP also responded to challenges such as war, conflict, and the COVID-19 pandemic by supporting patrols, training, and health measures to ensure the species' survival. Its mission focuses on securing the future of mountain gorillas through collaboration, science, responsible tourism, and community involvement, contributing to regional conservation efforts and long-term species sustainability.

Group-living animals face a number of threats from extragroup conspecifics: from individuals seeking mating opportunities to rival groups attempting to access limited resources. The consequences of intergroup interactions can therefore include loss of mates, increased energy expenditure, and injury or death. There is increasing evidence that aggressive intergroup interactions can affect subsequent intragroup behavior, and that such post-conflict behavior may be directly related to the threats posed by different opponent groups (e.g., familiar vs. unfamiliar). However, empirical evidence for changes in intragroup behavior following intergroup conflict in social animals is limited. We compared the proximity and behavior of group members before and after 84 aggressive intergroup interactions involving 14 study groups of wild, habituated mountain gorillas (Gorilla beringei beringei) in Volcanoes National Park, Rwanda. Intergroup conflict affected subsequent intragroup behavior in several ways. We found that immediate movement away from the opponent following intergroup conflict was less likely between familiar groups compared to unfamiliar groups. However, both winning and losing groups spent twice as much time moving post-conflict, and losing groups spent less time resting. There was an increase in female intragroup affiliative interactions and a decrease in male intragroup agonistic interactions post-conflict. These results demonstrate that such intergroup contests can influence intragroup dynamics beyond the immediate period of interaction.

Rwanda is an African country that has many mountains covered by forests. These forests are friendly homes to different animal’s species that make them a favorite environment for tourists. The most attractive geographical ecosystem is Rwanda's national volcano park(NVP) forest, the place where mountain gorillas are located. Gorillas are among the animals that are mostly visited by tourists in Rwanda, and they are moving inside the large forest looking where there is enough food. These displacements in such an environment complicate the guards and tourists to located them easily. In this research thesis, we provide a solution to determine the gorillas’ location in real-time using Internet of Things (IoT) technology. The resources used include various sensors, Arduino microcontroller, ESP8266 module and communication protocols such as MQTT. Gorillas can be detected using different parameters such as their colors and height among others.

The mountain gorilla is a subspecies of the eastern gorilla species, living in tropical forests at high altitudes in central Africa. They are characterized by a heavy body shape, dark coat, and can weigh up to 180kg for males and 90kg for females. Mountain gorillas live in groups typically consisting of several females and their young, led by a dominant silverback male. They mainly move on the ground, walking on all fours, but can climb trees if needed. They inhabit isolated populations in Uganda, Rwanda, and the Democratic Republic of Congo, and are classified as Critically Endangered, with around 880 individuals remaining in the wild. Conservation efforts are underway to protect and increase their population, despite threats from habitat loss, human conflict, and disease.

Forty years ago, mountain gorillas faced near extinction due to poaching and habitat loss, with only about 240 individuals remaining. Thanks to long-term protection efforts initiated by Dian Fossey and continued by organizations like the Fossey Fund, their population has increased to over 600, leading to a reclassification of their conservation status from critically endangered to endangered. This success highlights the importance of sustained conservation efforts, international collaboration, and community involvement. Despite this progress, significant threats such as limited habitat, disease, human pressures, and climate change remain, requiring ongoing protection. The case of mountain gorillas demonstrates the impact of dedicated conservation work and the need for continued efforts to ensure their survival.

Illegal activities and use of park resources are the main challenges facing mountain gorilla (Gorilla beringei beringei) conservation and the protection of their habitats in the East Africa’s Greater Virunga Transboundary Landscape (GVTL). Indigenous residents around GVTL are considered the primary illegal users of park resources. Despite this, there is limited understanding of the current and past perceptions of indigenous residents living in communities adjacent to two GVTL parks; Volcanoes National Park in Rwanda and Mgahinga Gorilla National Park in Uganda. Equally, there is also limited understanding regarding the actual incidences of illegal activities inside both parks. This paper addresses these gaps. Perception data were collected from indigenous residents living adjacent to both parks. Further, Ranger-based Monitoring (RbM) data from both parks were analyzed to determine actual numbers and types of illegal activities over the 9-year period. Interestingly, findings indicated that residents perceived the prevalence of illegal activities to be decreasing across GVTL. To the contrary, RbM findings indicated that the number of actual illegal activities was increasing significantly, particularly in Volcanoes National Park. The discrepancy found between the two perspectives provides for a discussion of the social biases potentially present in these data, and their implications for management. Results also illuminated the subsistence-related nature of most illegal behaviors and suggest that to reduce illegal activities and local dependency on park resources, park management must work with communities and support them in tapping into alternative livelihoods and finding ways to address community household subsistence needs.

Ebola virus is highly lethal for great apes, with estimated mortality rates up to 98%, reducing the global gorilla population by approximately one-third. Mountain gorillas (Gorilla beringei beringei), with just over 1000 individuals remaining, are endangered and vulnerable to decimation from outbreaks. Using simulation modeling, this study evaluates the potential impact of an Ebola outbreak on the Virunga Massif gorilla population, indicating rapid spread due to high contact rates among groups, with less than 20% survival projected at 100 days post-infection of a single gorilla. Vaccination strategies increase survival but do not prevent widespread infection; however, vaccinating at least half the habituated gorillas within 3 weeks of initial infection could achieve survival rates over 50%. The findings highlight the importance of proactive vaccination and disease management to mitigate the devastating effects of Ebola on this endangered species.