species of gorilla are currently recognized: a western species (Gorilla
gorilla) and an eastern species (Gorilla beringei) (Groves,
2001; Grubb et al., 2003). The western gorilla species is divided
into two subspecies: the western lowland gorilla (Gorilla gorilla
gorilla) and the Cross River gorilla (Gorilla gorilla diehli)
(Sarmiento and Oates 2000; Groves 2001; Grubb et al., 2003). Eastern
gorillas are divided into two subspecies, mountain gorillas (Gorilla
beringei beringei) and Grauer's gorillas (Gorilla beringei
graueri), with the mountain gorillas further divided into two
distinct subpopulations (Virunga and Bwindi).
Bwindi, mountain, or Virunga gorilla
G.b. graueri: eastern lowland gorilla or Grauer's gorilla
G.g. diehli: Cross River gorilla
G.g. Gorilla: western lowland gorilla
Species (Gorilla gorilla)- CRITICALLY
Precise estimates of the numbers of western lowland and Cross River
gorillas are not available. In the late 1990s it was estimated that
there were as many as 110,000 western gorillas in Central Africa
(Harcourt 1996; Butynski 2001). However, high levels of hunting
and recent outbreaks of Ebola mean that the number of animals is
likely considerably less today. Though tens of thousands of western
lowland gorillas still remain, the number of Cross River gorillas
is orders of magnitude less. Current estimates suggest that fewer
than 300 individuals of this subspecies are left (Oates et al.,
to the extreme threat of extinction faced by Cross River gorillas
and western lowland gorillas, The
World Conservation Union (IUCN) classifies both species as Critically
Endangered. The Cross River gorillas are the most endangered ape
- Text by Richard Bergl, Ph.D.
and Lash, G.g. gorilla, Jacksonville Zoo and Gardens
(photo by Marian Brickner)
Species (Gorilla beringei)- ENDANGERED
Both subpopulations of mountain gorillas are classified
as Critically Endangered by
The World Conservation Union (IUCN). Recent census work found
populations of 380 Virunga and 320 Bwindi mountain gorillas (Gray
et al., 2005). Grauer's gorillas (formerly known as eastern lowland
gorillas) are listed as Endangered by the IUCN but their current
numbers are unknown. It is thought that the population has suffered
declines during the recent civil war in the Democratic Republic
of Congo, and it is estimated that between 5,500 and 28,000 remain
Text by Tara S. Stoinski, Ph.D.
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