Cross River Gorilla
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Cross River Gorilla ( Gorilla gorilla diehli ) |
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| Gorilla gorilla diehli | ||||||||||||
| Matschie , 1904 |
The Cross River gorilla ( Gorilla gorilla diehli ) is one of two subspecies of western gorillas from the primate family of apes (Hominidae). It is the most north-westerly and with only a few hundred animals one of the most threatened gorilla populations.
features
From the western lowland gorilla , the second subspecies of the western gorilla, it differs in the structure of the skull and teeth. The cross-river gorilla, for example, has narrower teeth, a narrower palate and a shorter skull. Dimensions on a single animal suggest that it could have shorter hands and feet, although otherwise it is no different in size and length of limbs from the second subspecies.
distribution
Cross River gorillas occur exclusively in the border region between Nigeria and Cameroon and are named after the Cross River that runs there. They are thus the most north-westerly gorilla population and 250 to 260 kilometers from the range of the western lowland gorillas. In the 19th century the area inhabited by the species covered around 22,000 km², today it is still 4000 km². Within this area, interchangeable populations of the species occur in eleven different locations, which together have an area of only 400 km². In contrast to the western lowland gorilla, cross-river gorillas do not live in deep-lying forests, but only in mountain regions with submontane forests up to 2000 meters above sea level. Only occasionally do they switch to the lowlands between the hills. The average annual rainfall in the distribution area is 1800 to 4500 mm, the minimum temperature is 14 to 25 ° C, the maximum temperature is 24 to 36 ° C.
Way of life
Little is known about the way of life. The monkeys live in family groups, which in most cases consist of fewer than 6 animals. A large group of around 20 individuals is known only from the Afi Mountains . The distribution area of the Cross-River-Gorilla is characterized by distinct seasons. The animals prefer ripe fruits, but during the four to five month dry season these are less available and the gorillas feed more on leaves, saplings, pith and bark. In the Afi Mountains in the Nigerian part of the range, the leaves of Landolphia are a staple food for the monkeys in the dry season.
Systematics
When they were discovered in 1904, they were systematically described as a separate species ( Gorilla diehli ), later they were simply listed as a population of the western lowland gorilla. Investigations on museum specimens by Esteban E. Sarmiento and John F. Oates in 2001 finally came to the result that it is a separate subspecies due to the morphological differences.
Danger
The total population of cross-river gorillas is estimated at 250 to 300 animals, the IUCN lists them as " critically endangered ". Their distribution area is split up into around ten small regions, which cover approx. 8000 km², whereby the animals in most of them enjoy no legal protection. In Nigeria this affects the areas on the Obudu Plateau . The destruction of their natural habitat and hunting are the main threats, although efforts are now being made to convert some of the habitats of the Cross River gorillas into protected areas. This affects the areas in the Afi Mountains and Mbe Mountains . These projects try to win over the local population to protect the gorillas.
To protect the Cross River gorillas, the governments of Cameroon and Nigeria have established Takamanda National Park and Cross River National Park .
In 2011 and 2013, the Central African Central Bank put silver coins with the image of the Cross River gorilla into circulation. They have a face value of 1,000 Francs CFA and were issued in a limited number of 888 pieces each.
literature
- EA Williamson & Thomas Butynski : Gorilla gorilla Western Gorilla, page 39-45 in Thomas Butynski, Jonathan Kingdon and Jan Kalina (eds.): Mammals of Africa Volume II. Primates. Bloomsbury, London, 2013, ISBN 978-1-4081-2252-5
Individual evidence
- ^ Williamson & Butynski (2013), p. 40.
- ^ Williamson & Butynski (2013), p. 43.
- ^ Williamson & Butynski (2013), p. 42.
- ↑ Esteban E. Sarmiento, John F. Oates: The Cross River Gorillas: A Distinct Subspecies. In: American Museum Novitates 3304 (2000), pp. 1-55. Abstract
- ↑ Gorilla gorilla ssp. diehli in the endangered Red List species the IUCN 2006 Posted by: T. Butynski & Members of the Primate Specialist Group, 2000. Retrieved on June 14 of 2007.
- ↑ Report on Primate Surveys and Conservation On the Obudu Plateau Cross River State, Nigeria ( page no longer available , search in web archives ) Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice. Author: Daniel Louk (The Biodiversity Research Program The Nigerian Conservation Foundation and the Wildlife Conservation Society) (PDF file; 157 kB)
- ↑ Mbe Mountains Community Wildlife Sanctuary on WCS Nigeria (English)
- ↑ http://news.bbc.co.uk/2/hi/science/nature/7754544.stm
- ↑ Description of the Cross River National Park on Nigeria Park Service ( Memento of the original from March 15, 2013 in the Internet Archive ) Info: The archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this notice. (English)
- ↑ Description of the silver coin (edition) 2011 ( Memento of the original from April 14, 2013 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. (German)
- ↑ Description of the silver coin (2013 edition) (German)
Web links
- IUCN / SSC Primate Specialist Group data sheet
- Gorilla gorilla. In: Animal Info. March 2, 2005, archived from the original on November 11, 2018 ; accessed on May 11, 2019 (English, information on lifestyle and population numbers).
- KA Cawthon Lang: Primate Factsheets: Gorilla (Gorilla) Taxonomy, Morphology, & Ecology. In: Primate Info Net . October 4, 2005, accessed May 11, 2019 .