Mountain Gorillas: Three Decades of Research at Karisoke. Robbins, M. M., P. Sicotte, and K. J. Stewart . 2001 . Cambridge University Press , New York, NY . 444 pp. $80.00 (hardcover). ISBN 0-521-78004-7 .

Mountain gorillas ( Gorilla gorilla beringei ) are surely the most remarkable animals on Earth. They are at the top of the charisma stakes and, with the giant panda, have become a symbol of conservation in the eyes of the general public. The gorillas have proved perfect ambassadors, and their image has been effectively harnessed to raise funds from the general public and awareness at home and abroad. Threatened with extinction in the 1970s, mountain gorillas were saved by a pioneering integrated conservation program of law enforcement, education, and tourism. Conservation efforts were driven initially by researchers, who refused to see their study animals disappear. This edited book, based on a conference held in 1999, provides a synthesis of scientific knowledge of the mountain gorillas of Karisoke, the research center established by Dian Fossey in Rwanda in 1967, against the backdrop of the conservation saga of the past three decades.

Mountain gorillas live in the stunning landscape of the Virunga Volcanoes, eight peaks that straddle the boundaries of Rwanda, The Democratic Republic of Congo ( DRC, formerly Zaire ), and Uganda. Contiguous national parks protect 430 km2 in which about 320 gorillas live. Horror beyond description has buffeted the area with enduring wars, genocide, and massive movement of refugees within and between the three habitat countries. Yet, miraculously, the gorillas survive. Research and researchers have played a central role by collecting and analyzing a wealth of data, including long-term demographic records of the habituated study groups and periodic censuses of the whole population. The long-term scientific study of the ecology and especially the behavior of the gorillas provides unique insights into the complexity of gorilla society. Research at Karisoke also has fueled many popular articles, films, and public lectures. A committee could not have designed a better flagship species than mountain gorillas. Their physical appearance combines high cuddle factor ( infants and juveniles ) with imposing majesty (silverback males ); their ecology is non-threatening ( gentle salad-eaters ); and their behavior evokes respect ( males protect females and young from intruders with terrifying displays, yet humans have been able to enter their daily lives and observe them at very close range ).

The editors begin the book with a concise overview of the history of Karisoke since 1967 and set the scene for the following 13 chapters. These are grouped in four sections: “The Social System of Gorillas,”“Within-group Social Behavior,”“Feeding Behavior,” and “Conservation and Management.” The book ends with an afterword, “Mountain Gorillas at the Turn of the Century,” which reflects on the momentous conservation effort that has brought a viable population of mountain gorillas into the twenty-first century and suggests how this should best continue. Most chapters present synthetic overviews of topics based on long-term data; a minority report on studies more limited in time and scope. Comparisons with other populations of gorillas are made in two chapters to place the Karisoke gorillas in a broader context.

Overall, the editors have done an excellent job of making the book cohesive and informative. All chapters contain useful summaries and independent bibliographies, which make the book accessible to both general readers and those with more specific interests. The book deserves wide attention as, in addition to the solid academic content of behavioral and ecological research, the conservation context provides a classic case study. In this review, I focus on the parts of the book that address conservation issues most directly. None of the content is irrelevant to conservation. Information about demography, social organization, and behavior are essential for planning, and the long-term research at Karisoke has revealed trends and variability, for example, in group size and composition within the population that reflect its conservation status.

The long, intertwined history of research and conservation at Karisoke described briefly in the introductory chapter is developed in chapter 14 ( Plumptre & Williamson ), which details the different threats faced by the Karisoke gorillas over time and examines the role of research in management. The bare facts about the gorillas of the Virungas are dire. After the first census, the population declined from about 450–500 in 1960 to 252 in the 1970s and then recovered to about 320 by 1989. No complete census has been possible since 1989 because of civil unrest, but research groups have been monitoring, and the population is believed to be stable or even increasing. The alarming decline during the 1970s was due principally to the loss of 100 km2 of prime habitat that was cleared for industrial plantations. Illegal cattle grazing was also a problem, and hunting for trophies ( heads, hands, and feet of adult males) and live infants ( obtained by killing the mother and often males trying to defend the group) took a significant toll on the habituated study groups. The major threats currently facing the gorillas are war and exposure to human disease.

In the early years, Karisoke researchers drove the fight to protect the gorillas from poaching and illegal cattle grazing by organizing patrols to remove snares and prevent encroachment. The scale and scope of conservation activities changed in the 1970s in the face of a plan to excise an additional 52 km2 of the park for agricultural development. A successful fund-raising campaign led to the creation of The Digit Fund ( for research and antipoaching measures at Karisoke) and The Mountain Gorilla Project ( MGP ). The MGP developed a multifaceted conservation strategy based on law enforcement, education, and ecotourism and had the organizational capacity and funds to convince the Rwandan government that this avant garde, integrated conservation and development proposal was preferable to agricultural conversion.

Plumptre and Williamson stress the importance of broadening the scope of research at Karisoke to take into account the ecosystem in which the gorillas live. They underline the need for socioeconomic research around the park to assess threats, monitor the success of education programs, and improve the effectiveness of conservation activities. Chapter 10 ( McNeilage ) provides an excellent example of conservation-orientated research that has identified key features of habitat quality in different parts of the Virungas and allowed estimation of the habitat's carrying capacity for gorillas at about 650 individuals, thus giving a concrete target for management.

The role of tourism in saving the mountain gorillas of the Virungas is well known. The experience of seeing these magnificent animals going about their daily business is unique. The Rwandan model has been replicated in both Uganda and the RDC, and revenue from tourism allows the gorillas to more than “pay their way,” creating a strong positive incentive for their protection. Plumptre and Williamson present a salient analysis of the pros and cons of gorilla tourism in Rwanda. The advantages of job creation and in-country earnings of up to $1 million per year have made the gorillas a national symbol and a source of pride reinforced by strong international concern. Improved law enforcement protects the gorillas from poaching and encroachment and affords them a remarkable degree of protection even during the horrendous times of civil war. The negative impacts of tourism include increased stress, behavioral disruption, and vulnerability to poaching due to the loss of fear of humans, but the biggest threat is disease transmission.

This concern is addressed in chapter 13 ( Mudakikwa et al. ), which describes the veterinary program for gorilla health care that began in 1985. An astonishing 60% of the Virunga gorillas are habituated to humans and are contacted on a daily basis by researchers, park guards, or tourists. The present policy on veterinary management restricts their field of action to observation and collection of noninvasive samples, except in unambiguously life-threatening situations, such as gorillas being caught in snares. Mudakikwa et al. point out that detecting any negative impacts on gorilla health requires baseline data on their naturally occurring infections. They make a case for a more proactive approach involving periodic anesthetizing of gorillas in order to collect baseline data and allow early detection of infectious disease. Decisions about invasive procedures for preventative medicine (collecting blood or administering vaccines) or for clinical intervention ( treating disease or injuries sustained in fights ) remain controversial. The present system relies on explaining the risks carefully to tourists and enforcing strict guidelines during visits to gorillas. People suffering from any illness are turned away, children under 15 years are not allowed, a minimum distance of 7 m is kept between people and gorillas, and human feces are buried at least 30 cm deep. No proven case of disease transmission between mountain gorillas and humans has been recorded, but it remains a potent threat.

In the final chapter of part IV, Steklis and Gerald-Steklis review the conservation status of the Virunga gorillas. The importance of the long-term data on population size and structure and the need for regular monitoring are made clear. It is not easy to collect population-wide data because the Virunga conservation area is shared by three countries. Threats and circumstances have often varied, notably hunting for meat, which is more common in the RDC for cultural reasons and because antipoaching patrols are less intense there. This chapter provides a factual account of the changes in status of the gorilla population over the past 30 years and identifies degree of protection and habitat quality as factors influencing group size, which is a proxy for population health.

Discussion of various PVA analyses follows, and the chapter ends with the encouraging conclusion that the Virunga population is robust, despite a small effective population size of 80–120 ( based on the 1989 census results ), because it is buffered from stochastic events by a long generation time and strong growth potential. Modeling the effects of viral disease or the chronic effects of war did not produce catastrophic scenarios, with the probability of extinction within 100 years never reaching 10%. Based on this, Steklis and Gerald-Steklis conclude that mountain gorillas ( regardless of whether or not this includes the Bwindi population in Uganda whose taxonomic status remains unclear ) should be downgraded from critically endangered to endangered status. I was surprised to read this and disagree strongly. The fact that over 9 months ( 1998–1999 ) in Kahuzi-Biega National Park, RDC, park guards were disarmed and unable to patrol effectively, when 60 of 94 habituated eastern lowland gorillas were killed by bushmeat poachers, should shake all PVA modelers to their roots ( Yamagiwa and Kahekwa's account, chapter 4 ). The suggestion to downgrade the World Conservation Union's conservation category of the Virunga gorillas is at best premature and at worst irresponsible.

The Virunga mountain gorillas represent a classic case history for students of conservation biology, who need to learn that in practice conservation requires compromise, partnerships, and adaptive management responsive to feedback and changes. This message is eloquently made in the book's finale by Weber and Vedder, which presents an insightful account of the huge achievements that grew from research at Karisoke. Taken as a whole, this well-written book provides an unparalleled vision of mountain gorilla society against a background of a conservation saga that could so easily have ended with extinction. The introduction, chapter 14, and the afterword should be read by all students of conservation biology. Chapter 4 should be read by everyone as a reminder that if the Virunga gorillas have truly been saved, an element of luck has been involved.