Hello again, welcome back to animals under threat. Today,
we will be covering a subspecies of Western Gorilla that is found near the Cross
River in Nigeria. This subspecies was once considered to be extinct in the wild
until scientists found a small population in 1980’s. Classed by the IUCN as
Critically endangered and is one of Africa’s most endangered species. Say hello
to the Cross River Gorilla (Gorilla gorilla spp. diehli).
This subspecies looks similar to the Western
lowland Gorilla with the only differences in the skull size and tooth dimensions
(Bergl et al, 2016). Cross River Gorillas prefer dense forest habitat but can
live in riparian forests and high altitude grasslands. Their diet depends on
which habitat they reside in as they prefer fruit during periods of seasonal
abundance and herbs and bark through out the rest of the year (Etiendem &
Tagg, 2013).
Photo
of Cross River Gorilla eating by Nicky Lankester, Limbe Wildlife Centre (above) and Male gorilla by Wildlife Conservation Society (below).
Cross River Gorilla are one of the lesser known species
as current studies estimated that there are 200-300 individuals left in the
wild with estimated number of individuals in a group to be around 11 by examining
nests left by the Gorillas (Funwi-Gabga et al, 2012). Each group is led by a
male and the females and his young make up the rest of the group. Lead male
Gorillas are sometimes called “silverbacks” due to the silver colour on their
back (Worldwildlife.org, 2020).
Poaching, habitat destruction, climate change and
inbreeding are some of the major threats to the Cross River Gorilla survival. Gorillas
are sometimes caught in snares set by poachers to catch other animal species.
The trapped Gorilla struggles to escape the snare this can result in injury or
death. Habitat destruction of their major food sources for agricultural reasons
has led to conflict between humans and Gorillas and with increasing climate
change has force the Cross River Gorilla to move to other areas where they may
be unable to survive in. Due to the small population, inbreeding is a big risk
as lack of genetic flow between groups and lead to deformities in future
generations and higher risk of diseases due to poor immune systems (Bergl et
al, 2016).
Next time, we will be covering a species of wombat from
Australia.
References
Bergl, R.A., Dunn, A., Fowler, A., Imong, I., Ndeloh, D.,
Nicholas, A. & Oates, J.F. 2016. Gorilla gorilla ssp. diehli (errata
version published in 2016). The IUCN Red List of Threatened Species 2016:
e.T39998A102326240.
Etiendem, D.N. & Tagg, N. 2013, "Feeding Ecology
of Cross River Gorillas (Gorilla gorilla diehli) at Mawambi Hills: The
Influence of Resource Seasonality", International Journal of Primatology,
vol. 34, no. 6, pp. 1261-1280.
Funwi-Gabga, N., Funwi-Gabga, N., Mateu, J. & Mateu,
J. 2012, "Understanding the nesting spatial behaviour of gorillas in the
Kagwene Sanctuary, Cameroon", Stochastic Environmental Research and Risk
Assessment, vol. 26, no. 6, pp. 793-811.
https://www.worldwildlife.org/species/cross-river-gorilla
retrieved 28/6/2020
Picture references
https://www.iucnredlist.org/species/39998/102326240
