Background of the study
The vast lowland forests of central Africa host the western lowland gorilla, which is scientifically referred to as the ‘gorilla gorilla gorilla.’ This is the most widespread and common of the four distinct subspecies of gorillas. Accurate and reliable estimations of their numbers are so far not possible because these primates live in some of the most remote and densest parts of Africa’s rainforests (Berthelet & Chavaillon, 1993). Regardless the total population of these primates was approximated at 100000 individuals in 1980s and has been declining ever since then.
Golden lion tamarins are another group of the primate family. These are orange-yellow-like monkeys, which are relatively small in size. They inhabit the Brazilian coast, where a meager part of the forest still remains. These primates are highly endangered because of the fragmentation of their habitat (Berthelet & Chavaillon, 1993). Each habitat is quite small and this leads to congestion. Human intervention has facilitated the shifting of some of these primates to other habitats so as to ensure that they do not become extinct. This is due to the fact that inbreeding poses a great threat to the sustainability of these primates. Human intervention refers to the actions taken by the Brazilian government, the national zoo, partnering organizations and other zoos.
Graphics
Courtesy of Martin HARVEY / WWF-Canon
Courtesy of Flickr Photo Sharing
Geographic Distribution in the Wild
The lowland swamps and forests in central Africa are the natural habitat of the western lowland gorilla. These habitats are found in Cameroon, Angola, Gabon, and Equatorial Guinea. The wild populations of these primates are unfortunately critically endangered (Fuentes & Wolfe, 2002). Illegal hunting and infection with Ebola are among the major sources of threats to their continued existence. Human activities such as farming, deforestation and grazing are some of the other factors that lead to this situation.
Golden lion tamarins (GLTs) are found in lowland and coastal rainforest areas. They are extremely endangered since their natural habitat has been divided into small areas, which are not connected. There are an estimated 1,500 golden lion tamarins that are in the wild. Most of these primates inhabit the area near the state of Rio de Janeiro, particularly Reserva Biologica de Poço das Antas. Another 450 live in zoos all over the world.
Social Behavior
Of the gorilla family, the western lowland gorillas exhibit the smallest family size of all gorillas of between four to eight members. Generally the adult males do not live in bachelor groups. They prefer to have the company of adult females around them. However, according to Fuentes & Wolfe (2002), the composition of the primate groups typically comprise of one adult male, juvenile females, and juvenile males. When the adult male passes on, the reproductively active adult females move into other groups (Fuentes & Wolfe, 2002). This type of behavior is highly attributed to infanticide.
Similarly, the family group of golden lion tamarins often consists of between two to eight individuals. Basically these are a mated pair and their offspring, and sometimes other members of the family. In zoos, GLTs are enclosed according to family groups. In the wild, groups are relatively small, that is, between 2-9 primates and often comprise of one adult male, one adult female and younger primate. Family relations may exist between group members. In spite of that the movement of individuals from one group to another is relatively common (Fuentes & Wolfe, 2002). Each group of tamarins is expected to protect its territory against intrusion by other tamarin groups. The protection of a territory is achieved through marking of scent during ritualized group confrontations and vocalizations. The tamarins do not actually physically fighting.
Conservation status
Currently, western lowland gorillas and golden lion tamarins are critically endangered. Their numbers have been dwindling over the years because of increased human activity that leads to the disturbance of their habitat (Gavan, 1955).The projects initiated by various stakeholders need to be supported in order to save these primates from extinction.
Other information that you see fit
Golden lion tamarins have a gestation period of between 126-130 days. The time to weaning is about 90 days (Gavan, 1955). The sexual maturity age is approximately 18 months. While in captivity, the life expectancy is about 8 years for tamarins that manage to survive past the stage of infancy—40 percent of infants die before 1 year. Their longevity record currently stands at 31 years.
Conclusion and recommendation
In summary, increased human activity has continued to make it more difficult for non-human primates to survive. The constant conflict between then human activity and wildlife conservation is an issue that needs to be adequately addressed by all stakeholders. Activities such as illegal logging and the encroachment of wildlife habitats for farming and human settlements is a matter that governments need to address in order to ensure that important primates such as the Western lowland gorilla and the golden lion tamarin are not driven into extinction (Gavan, 1955). Some of the projects that can be initiated to protect these primates include:
- Improving on the security of protected areas where western lowland gorillas, golden lion tamarins, and other threatened species live.
- Intensifying the use of tracking devices to monitor the movement of the primates in the protected areas.
- Sensitizing the local communities on the importance of safeguarding these primates from human aggression. The programs should teach locals on how to handle the primates properly in case of trespass on their property.
(Berthelet & Chavaillon, 1993)
References
Berthelet, A., & Chavaillon, J. (1993). The Use of tools by human and non-human primates. Oxford [England: Clarendon Press.
Fuentes, A., & Wolfe, L. D. (2002). Primates face to face: Conservation implications of human and nonhuman primate interconnections. Cambridge, UK: Cambridge University Press.
Gavan, J. A. (1955). The Non-human primates and human evolution. Detroit: Wayne University Press.
Golden Lion Tamarin | Flickr - Photo Sharing! (n.d.). Retrieved from http://www.flickr.com/photos/nationalzoo/5998210030/?rb=1
Primate Seasonality Symposium, B., Schaik, C., & International Primatological Society (2005). Seasonality in primates: Studies of living and extinct human and non-human primates. Cambridge: Cambridge University Press.
WWF - Western lowland gorilla. (n.d.). Retrieved from http://wwf.panda.org/what_we_do/endangered_species/great_apes/gorillas/western_lowland_gorilla/
(Gavan, 1955) (Fuentes & Wolfe, 2002)
