Monitoring Endangered Gorillas in Africa
Daily monitoring of endangered gorillas provides protection, as well as scientific information on their lives and behavior.
Gorilla monitoring involves daily data collection on multiple aspects of the gorillas’ lives: births, deaths, transfers, health, ranging patterns, social behavior, feeding patterns.
Dr. Dian Fossey initiated this research in the 1960s in order to learn about the mountain gorillas' social organization and behavior. The studies she started at the Karisoke™ Research Center in Rwanda in 1967 are still ongoing today -- a period that included eight years of civil unrest in the 1990s -- and is one of the longest running studies of any animal species anywhere in the world.
Only two of the individual gorillas Dr. Fossey first identified are still being observed today. However, new generations of gorillas have grown up and we have data on their entire lives. This combination of longevity and detail on individual gorillas is unique to Karisoke™ and has allowed us to learn a significant amount about the social organization and behavior of the gorillas and how these change under different conditions.
Monitoring provides important information about gorilla life
As an example, in the 1970s and '80s the groups monitored by Karisoke™ staff were typical in size and composition for gorilla groups: they averaged 10-15 individuals, including one or two silverbacks and one or two blackbacks. By 2006, the three main groups we monitored had grown to 25-65 individuals and each group contained an average of nine silverbacks and blackbacks. Pablo's group, with 65 individuals and six silverbacks by late 2006, was the largest group of gorillas ever observed. As if this incredible growth wasn’t enough, beginning in March 2007, the groups began to split up and reorganize such that by mid-2009 the three groups had become nine! Such considerable changes have not previously been seen in our many years of observation and show the importance of long-term studies to fully understanding gorilla behavior.
By being present on a daily basis through all these changes, we have been able to observe relatively rare gorilla behaviors such as multiple female transfers, male dispersal, and dominance changes. It also has offered an unusual opportunity to observe changes in social dynamics as group sizes changed. The diversity in group makeup has also allowed us to investigate the differences between small and large groups, and between multi-male and single-male groups. We expect to see more dramatic changes, as some individuals have already formed temporary groups that continue to evolve.
At the Karisoke™ Research Center, we recognize that the more we know about mountain gorillas - about their lives, behavior and social systems - the better equipped we are to help them survive. For example, given that so little mountain gorilla habitat remains, the following question is often asked: has this population reached the carrying capacity of the park and if not, how long will it take them to do so? An enormous amount of data is required to answer this question. Estimating carrying capacity requires knowing what foods gorillas eat, how these foods are distributed throughout the habitat and how they vary seasonally as well as how much space a gorilla group requires. Estimating population growth rates requires a knowledge of the current population size, how many infants a female is likely to have in her lifetime (female reproductive output) and how many of those will survive to adulthood (infant survivorship). Daily monitoring provides much of this information and helps to develop conservation strategies for Karisoke™ and our conservation partners in Africa.
Monitoring results: gorilla protection
Daily observation of the gorillas plays an important role in their protection. Trackers and researchers note the presence of snares and other evidence of poachers, and inform our anti-poaching patrols; they note unusual absences of individual gorillas from their group; and if they see that a gorilla is ill or injured they will inform Gorilla Doctors, a Fossey Fund partner. As a result of daily, all-day monitoring as well as anti-poaching and other efforts, the mountain gorillas of the Virungas are the only great ape population to have increased in recent decades, from about 260 in Fossey’s time to 480 individuals at the last census in 2010.
Monitoring gorillas in the Congo
Following Karisoke’s success, communities in the Democratic Republic of Congo established a network of 10 unique community-based nature reserves, on land donated by local families. They link two national parks to create a wildlife corridor that includes almost the entire range of the endangered and little-known Grauer’s (eastern lowland) gorilla. The Fossey Fund has established a Grauer's Gorilla Research and Conservation Program based on the Karisoke model and managed by the Fund, to learn more about the Grauer's gorillas and begin direct monitoring and protection. The program has established an operations and field research center deep in the forest, in a community-based reserve, and trained Congolese field staff to survey, locate and monitor selected groups of gorillas. They are studying the Grauer's gorillas' density, feeding ecology and ranging patterns, and are identifying gorilla groups in the area.