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The
population of mountain gorillas has been the subject of research
and debate over the last 35 years. However, during the past
18 years, the region has frequently been affected by political
instability and war, resulting in unreliable accounts of a
proper gorilla population. In 2003, the mountain gorilla population
surrounding the Virunga Volcanoes was estimated to be in the
vicinity of 380 individuals (16 habituated groups consisting
of 269 individuals, 12 non- habituated groups consisting of
80 individuals, and 11 lone silverbacks).
History
of population
In
1959-60, George Schaller estimated a population size of between
400 and 500 Virunga mountain gorillas. His population estimate
was based on detailed observations of gorilla groups around
Kabera meadow in Virunga National Park and within the Ugandan
area of the VVR, limited observations in the area between
Sabyinyo and Visoke volcanoes and extrapolations based on
estimations of available gorilla habitat.
Between
1971 and 1973, detailed censuses were conducted and the
total population was found to have declined to 260 and 290
individuals (Harcourt & Groom, 1972; Groom, 1973). Further
census efforts were then undertaken in 1976 and 1978 and
the population was estimated to be between 252 and 285 individuals
(Webber & Vedder, 1983).
A
census conducted in 1981 showed a continued gradual decline
in total population size (Aveling & Harcourt, 1984)
with an estimate of between 242 and 266 individuals. During
the mid-80’s, the Virunga mountain gorilla population
began to increase in size and the 1986 census reported a
total population size of between 252 and 285 individuals
(Vedder & Aveling, 1986). A subsequent census in 1989
showed further growth in the gorilla population (Sholley,
1991). A total of 309 individuals were counted resulting
in an estimated population size of 324. There was an increase
in both the number of individuals and groups since the 1986
census. The population growth during the 1980’s is
widely attributed to increased monitoring and protection
efforts throughout the park.
From
1989 to 2003, it was not possible to undertake a census
due to insecurity. However, it was known that gorillas had
died as a direct result of the insecurity in the park (Kalpers
et al., 2003). An estimation of the population size was
made in 2000 based on knowledge of regularly monitored groups
and information gathered during…………..
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