Cross River gorilla
|Cross River gorilla|
|Subspecies:||G. g. diehli|
|Gorilla gorilla diehli
The Cross River gorilla (Gorilla gorilla diehli) is a subspecies of the western gorilla (Gorilla gorilla). In 2009, the Cross River gorilla was finally captured on professional video on a forested mountain in Cameroon.
Description, comparison to other subspecies 
The morphological distinctiveness of the Cross River Gorilla was first recognized in 1998. Subsequent analyses of cranial and tooth morphology lent support to the distinctiveness of the Cross River gorilla and the gorilla was described as a distinct subspecies in 2000.
A study published in 2007 in the American Journal of Primatology announced the discovery of the subspecies fighting back against possible threats from humans. They "found several instances of gorillas throwing sticks and clumps of grass". This is unusual. When encountered by humans, gorillas usually flee and rarely charge.
Geographical distribution 
This subspecies is populated at the border between Nigeria and Cameroon, in both tropical and subtropical moist broadleaf forests which are also home to the Nigeria-Cameroon chimpanzee, another subspecies of great ape.
Estimates on the number of Cross River gorillas remaining is 250–300 in the wild, concentrated in approximately 9–11 locations. Genetic research published in 2007 and field surveys suggest these locations are linked by the occasional migration of individual gorillas. The nearest population of western lowland gorilla is about 250 km (160 mi) away.
Conservation status 
While all western gorillas are Critically Endangered (in the case of the western lowland gorilla due in part to Ebola virus), the Cross River gorilla is the most endangered of the African apes. It is one of the world's 25 most endangered primates according to the IUCN Primate Specialist Group.
Both loss of habitat and intense hunting for bushmeat have contributed to the decline of this subspecies. A conservation plan for the Cross River gorilla was published in 2007 and outlines the most important actions necessary to preserve this subspecies. In 2008, the government of Cameroon created the Takamanda National Park on the border with Nigeria as an attempt to protect these gorillas. The park now forms part of an important trans-boundary protected area with Nigeria’s Cross River National Park, safeguarding an estimated 115 gorillas—a third of the Cross River gorilla population—along with other rare species. The hope is that the gorillas should be able to move between the Takamanda reserve in Cameroon over the border to Nigeria's Cross River National Park.
- Oates, J. F., Bergl, R. A., Sunderland-Groves, J. & Dunn, A. (2008). Gorilla gorilla ssp. diehli. In: IUCN 2008. IUCN Red List of Threatened Species. Retrieved 4 January 2009.
- "World's rarest gorilla ready for its close-up", EurekAlert, 16 December 2009
- Stumpf, R.M., JG Fleagle, WL Jungers, J Oates, & CP Groves (1998). Morphological distinctiveness of Nigerian gorilla crania. American Journal of Physical Anthropology. Supplement 26: 213.
- Sarmiento, E. E. & Oates, J. F. (2000), "Cross River gorillas: A distinct subspecies, Gorilla gorilla diehli Matschie, 1904", American Museum Novitates 3304: 1–55, doi:10.1206/0003-0082(2000)3304<0001:TCRGAD>2.0.CO;2
- Stumpf, RM, JD Polk, JF Oates, WL Jungers, CP Heesy, CP Groves, & JG Fleagle (2002). Patterns of diversity in gorilla cranial morphology. In: Gorilla Biology: A Multidisciplinary Perspective. (A. Taylor and M Goldsmith, eds.). Cambridge University Press. Cambridge. pp 35-61.
- Wittiger, J. & Sunderland-Groves (2007), "Tool use during display behavior in wild cross river gorillas", American Journal of Primatology 69 (11): 1307–1311, doi:10.1002/ajp.20436
- "World's Most Endangered Gorilla Fights Back", Science Daily, December 11, 2007
- "Video - Rare Gorillas Caught on Camera". National Geographic. 2012. Retrieved 2012-05-09.
- Bergl, R. A. & Vigilant, L. (2007), "Genetic analysis reveals population structure and recent migration within the highly fragmented range of the Cross River gorilla (Gorilla gorilla diehli)", Molecular Ecology 16 (3): 501–516, doi:10.1111/j.1365-294X.2006.03159.x
- Mittermeier, R.A.; Wallis, J.; Rylands, A.B.; Ganzhorn, J.U.; Oates, J.F.; Williamson, E.A.; Palacios, E.; Heymann, E.W.; Kierulff, M.C.M.; Long Yongcheng; Supriatna, J.; Roos, C.; Walker, S.; Cortés-Ortiz, L.; Schwitzer, C., eds. (2009). Primates in Peril: The World's 25 Most Endangered Primates 2008–2010 (PDF). Illustrated by S.D. Nash. Arlington, Virginia: IUCN/SSC Primate Specialist Group (PSG), International Primatological Society (IPS), and Conservation International (CI). pp. 1–92. ISBN 978-1-934151-34-1.
- Regional Action Plan for the Conservation of the Cross River Gorilla
- Black, Richard (28 November 2008), "Protection boost for rare gorilla", BBC News
- "New National Park Protects World's Rarest Gorilla", Newswise, retrieved November 28, 2008
|Wikimedia Commons has media related to: Gorilla gorilla diehli|
- Cross River Gorilla Species Profile from the African Conservation Foundation
- Images and movies of the western gorilla (Gorilla gorilla) at ARKive
- Information on the Cross River Gorilla at WWF