[32], In the 1980s, a census of the gorilla populations in equatorial Africa was thought to be 100,000. They can be found from Cameroon, south to Angola, and across the Congo and the Central African Republic. From 2003–2004, two epizootics infected the western lowland gorilla, which caused two-thirds of their population to disappear. Female gorillas give birth to one infant after a pregnancy of nearly nine months. She can be found playing with Elle and Gladys or sitting near her dad, Jomo. These samples came from four field sites, all located in southern Cameroon. [13] Another of these factors is infertility. The simian immunodeficiency virus infected various African primates such as gorillas and chimpanzees.[54]. Standing height for males 5 feet 6 inches, arm span 7 feet 8 inches, weight 325 pounds. Western lowland gorillas are mainly herbivores, which means they eat plants. Snowflake, a male gorilla, was taken from the wild and brought to the Barcelona Zoo in 1966 at a very young age. The face only has hair along the … [42] Negative vigilance of visitor behaviors have been identified as starting, posturing and charging at visitors. They protect the gorillas with the isolation of their large swampy forest areas. The western lowland gorilla is the most numerous and widespread of all gorilla subspecies. Western lowland gorillas are the smallest of the four gorilla subspecies, which also include the Cross River gorillas, Grauer’s gorillas, and mountain gorillas. Their considerable size gives them a good defence against predators and they live in relative safety on the ground, more so than any other primate. A male does this in order to have the opportunity to mate with the mother, who otherwise would have been unavailable while caring for her young offspring.[17]. Habitat 4 is behind Habitat 3, and Habitat 5 is out of view. Among these teeth are strong sets of frontal canines and large molars in the back of the mouth for grinding fruits[3] and vegetables.[4]. An average refrigerator is 5.8 feet tall. Western lowland gorillas, although still the most abundant of the four types of gorillas, are listed as critically endangered by the International Union for Nature (IUCN), with threats including poaching and disease. [23], Western lowland gorillas primarily live in rain forest, swamp forest, brush, secondary vegetation, clearing and forest edges, abandoned farming fields and riverine forest. Although logging diminishes gorilla habitats, it may also provide for increased herbaceous vegetation as a result of gaps in the tree cover. Therefore, because of variation in these gorillas, it has been concluded that they display a moderate substructure within the western lowland population in general. [3] They may also eat insects from time to time. [50][51][52][53] The HIV-1 virus exhibits phylogeographic clustering, which is due to large rivers. This demonstrates the gorillas' acquisition of high level sensorimotor intelligence, similar to that of young human children. Females are significantly more likely to engage and participate in sexual behavior and activity on a day when another female is sexually active. In 1964 Ivan and another young gorilla -- a female named Burma -- were captured by poachers. Central Africa Endangered Status. Western Lowland Gorillas have broad shoulders, a muscular neck and strong hands and feet. [18], In the past, there was a gorilla that used a stick to measure the depth of water. It is the second child for the Western lowland gorilla, whose first baby, Yola, was born in 2015 when Nadiri was 19 years old. Varying exposure to different Anopheles mosquitoes transmitting Plasmodium species is known to be the origin of malaria in western lowland gorillas. [13], Female western lowland gorillas do not produce many offspring due to the fact that they do not reach sexual maturity until the age of 8 or 9. These infants ride on their mothers’ backs from the age of four months through the first two or three years of their lives. [40] Playing naturalistic auditory stimuli as opposed to classical music, rock music, or no auditory enrichment (which allows for crowd noise, machinery, etc. This species of gorilla is most likely to eat in the morning and afternoon. [39] Such stress reactions could be caused by sounds, light conditions, odors, temperature and humidity conditions, material makeup of enclosures, habitat size constraints, lack of proper hiding areas, forced closeness to humans, routine husbandry and feeding conditions, or abnormal social groups to name a few. The genetic variant for Snowflake’s albinism was identified by the scientists as a non-synonymous single nucleotide polymorphism located in a transmembrane region of SLC45A2. © 1996-2015 National Geographic Society, © 2015- [5] Males have an average weight of 140 kg (310 lb), females of 90 kg (200 lb). Young gorillas, from three to six years old, spend much of their day at play, climbing trees, chasing one another, and swinging from branches. Finally, the study sought out to analyze the allele frequency spectrum (AFS) in western lowland gorillas. Once the gorillas had given twigs to the humans, they would receive one of these objects. There is obvious sexual dimorphism. In the study done at Lope, gorillas harvest most of their food arboreally, but less than half of their night nests are built in trees. Laverania, which is a subgenus of the parasitic protozoan genus Plasmodium, was found in these studies. Though they’re normally quiet animals, western lowland gorillas have an extensive array of vocalizations—at least 22 different hoots, barks, and screams, each with its own meaning. Mondika is very curious and sociable. If the gorillas did not give them a twig, they would not get their desired object. Mammals Area. Western gorillas are exceptionally large and powerful primates. In the southern part of Cameroon, the populations of western lowland gorillas have had examinations of their feces. Gorillas do not display territorial behavior, and neighboring groups often overlap ranges. The back of males eventually turns to a grey colour the older they get, which leads to the term Silverbacks. Western lowland gorillas are the smallest of the four gorilla subspecies, which also include the Cross River gorillas, Grauer’s gorillas, and mountain gorillas. It appears that they also anticipate the use of the tool since they begin with biggest sticks available and progressively modify it until it is the perfect fit for inserting into a hole that contains food. [55] The catastrophe led the World Conservation Union to designate the western lowland gorilla a critically endangered species. Gorilla populations have also been ravaged by infectious diseases. Western lowland gorillas are four and a half to five and a half feet tall (1.4-1.75 m) when standing on their two legs. (1996): 58–70. [45], Recent research on captive gorilla welfare emphasizes a need to shift to individual assessments instead of a one-size-fits-all group approach to understanding how welfare increases or decreases based on a variety of factors. [29], The presence of western lowland gorillas has allowed humans to further the study of how gorillas compare with humans in regards to human diseases, behavior, linguistic and psychological aspects of their lives. Groups containing only one male are believed to be the basic unit of the social group, gradually growing in size due to reproduction and new members migrating in. [33][34], In 2002 and 2003, there was an Ebola outbreak in the Lossi sanctuary population, and in 2004, there was an Ebola outbreak in the Lokoué forest clearing in Odzala-Kokoua National Park, both in the Republic of the Congo. [54], The origin of AIDS has been linked to a virus known to infect more than 40 species of nonhuman primates in Africa. The diversity of fruits consumed was higher in the poor fruit year, when favored fruit species failed to produce large crops. Exhibit African Forest. They eat roots, shoots, fruit, wild celery, and tree bark and pulp. [14] Female gorillas give birth to one infant after a gestation period of nearly nine months. Unlike their powerful parents, newborns are tiny—weighing about four pounds—and are capable of doing no more than clinging to their mothers' fur. Nearly 80 percent of western lowland gorillas live in unprotected areas that are vulnerable to poaching. [8][9] The group usually favours a certain area within the home range but seems to follow a seasonal pattern depending upon the availability of ripening fruits and, at some sites, localised large open clearings (swamps and "bais"). [46] Analysis of the gorilla genome has cast doubt on the idea that the rapid evolution of hearing genes gave rise to language in humans, as it also occurred in gorillas.[48]. However, gorillas remain vulnerable to Ebola, deforestation and poaching. The estimated number of western lowland gorillas (G. gorilla gorilla), a species thought to be critically endangered, increased when a population of more than 100,000 was discovered in 2008 in the swamps of the Lac Télé Community Reserve in the Republic of the Congo. These infants ride on their mothers' backs from the age of four months through the first two or three years of their lives. These gorillas will occasionally eat insects such as termites, especially if plants are scarce, but their diet is mostly herbivorous. This Ebola outbreak also affected the Maya Nord population (52 kilometres northwest from Lokoué) from 400 individuals to considerably fewer. The western lowland gorilla is the most numerous and widespread of all gorilla subspecies. As it is a recessive allele, and his parents were an uncle and niece who were both carriers, this revealed the first evidence of inbreeding in western lowland gorillas. However, when ripe fruit is available, they tend to eat more fruit as opposed to foliage. Males weigh 300 to 600 pounds (136-272 kg). Climate change further threatens their habitat as warming temperatures dry out the region, making it more vulnerable to fire and forest retreat. Conservation Status The IUCN Red List notes that the Western lowland gorilla is critically endangered, and cites two major drivers of … They maintain relatively large home ranges in swamps and lowland forests, which provide food sources and nesting sites. All gorillas have a black coat but adult males also have a silvery-white “saddle” on their back. As a result, the western lowland gorilla’s numbers have declined by more than 60% over the last 20 to 25 years. In 2018, researchers surveying the gorilla’s range made an uplifting announcement: Their study found 361,900 western lowland gorillas—a third more than previously had been estimated. Gorillas have a characteristic body shape with a broad chest, heavy neck and strong hands and feet. This style of movement requires long arms, which works for western gorillas because the arm span of gorillas is larger than their standing height. [43] The western lowland silverback gorilla affectionately known as Ivan was born in 1962 in the Republic of the Congo (Léopoldville), which would later become the Democratic Republic of the Congo. Experts believe that the Ebola virus may have killed as much as a third of western lowland gorillas in the early 2000s. Gorillas eat leaves, fruit, and seeds. A male and female western lowland gorilla photographed at Gladys Porter Zoo in Brownsville, Texas. Out of 2,934 gorilla samples, 70 reacted with at least one HIV-1 antigen. Like their cousins, western lowland gorillas are endangered and face the loss of their habitat. Three out of four females have been observed to engaged in sexual behavior while pregnant and two out of three females have been observed to engage in sexual behavior while lactating. The leader organizes troop activities, such as eating, nesting in leaves, and moving about the group's home range. [14], A study of over 300 births to captive female gorillas revealed that older females tend to give birth to more male offspring as opposed to females under 8 years old. They sometimes also eat insects. This involved humans holding objects such as fruit, leaves or peanuts in one hand. It's also the only subspecies of gorilla kept in zoos, with few exceptions. Females are only half the weight of the males. "The IUCN Red List of Threatened Species", 10.1002/(SICI)1098-2345(1997)43:2<87::AID-AJP1>3.0.CO;2-T, "The genome sequencing of an albino Western lowland gorilla reveals inbreeding in the wild", "Home-range use and intergroup encounters in western gorillas (Gorilla g. gorilla) at Lossi forest, North Congo", "Impact of ecological and social factors on ranging in western gorillas", "Koko, the gorilla who mastered sign language, has died", "Impacts of logging and hunting on western lowland gorilla (, "Strategies for ovulation induction and oocyte retrieval in the lowland gorilla", "Motherlode of Gorillas Discovered in Central Africa", "More than 100,000 rare gorillas found in Congo", "Recovery Potential of a Western Lowland Gorilla Population following a Major Ebola Outbreak: Results from a Ten Year Study", "Monitoring Great Ape and Elephant Abundance at Large Spatial Scales: Measuring Effectiveness of a Conservation Landscape", "Assessing the prevalence and characteristics of hair-plucking behavior in captive western lowland gorillas (, "Insights into hominid evolution from the gorilla genome sequence", "Gorilla genome sheds new light on human evolution", "A Genome-Wide Survey of Genetic Variation in Gorillas Using Reduced Representation Sequencing", "The origins of acquired immune deficiency syndrome viruses: where and when? They have a fine, brownish coat, oft… This pattern is likely to result from selective pressures on females to have males at a time when they can provision them most effectively, as male reproductive success probably varies more than that of females and depends more on the maternal role. They have a black coat which covers their whole body except for their ears, feet and arms. Staple foods which are eaten on a daily/weekly basis throughout the year, seasonal foods which are present in the majority of resources when available and fallback foods which are always available, but eaten only or mainly during fruit-scarce months. The Western Lowland Gorilla is the smallest of all gorillas, but still has great size and strength. [40], Stereotypic behaviors are abnormal or compulsive behaviors. On August 7, Patterson began a more formal routine of teaching Koko the signs, "food", "drink", and "more". The study found that western lowland gorillas are more likely to be heterozygous than homozygous. The gorilla's coat color is black. Short, thin, gray-black to brown-black hair covers the entire body except the face. While the use and manufacture of tools to extract ants and termites is a well-documented behavior in wild chimpanzees, it has never been observed in other great apes in their natural habitat and never seen to be done by other primates in captivity. This population decreased from 377 individuals to 38 individuals two years after the outbreak and to 40 individuals six years after the outbreak. [3], Important food species have been divided into three categories. They never completely strip vegetation from a single area since the rapid regrowth of the vegetation allows them to stay within a reasonably confined home range for extended periods of time. While defended as being economically profitable for restaurants and local people, it is a large contributor to the endangered status of the western lowland gorilla. [49], Western lowland gorillas are believed to be one of the zoonotic origins of HIV/AIDS. Those who challenge this alpha male are apt to be cowed by impressive shows of physical power. Much of their day is spent in play, climbing trees, chasing one another and swinging from branches. The western lowland gorilla is considered to be critically endangered by the IUCN. All rights reserved. Because of these outbreaks, the International Union for Conservation of Nature (IUCN) updated the status of western lowland gorillas from "endangered" to "critically endangered". In this video you will see a Gorilla choose the ingredients for making beer at the world famous Santa Barbara Zoo’s “Zoo Brew” event. Endangered facts. These areas support the gorillas in both the wet and the dry season of the forest. Western lowland gorillas have a great impact on the development of tourism in Africa due to the fascinating features they contain. While in the dry season, there is a decrease in the consumption of fleshy fruits, but they still continue to eat other kinds of fruits. In captive gorillas, such frequent aberrant behaviors include eating disorders — such as regurgitation, reingestion and coprophagy — self-injurious or conspecific aggression, pacing, rocking, sucking of fingers or lip smacking, and overgrooming. Ivan was a western lowland gorilla born in 1962 in what is now the Democratic Republic of the Congo.He was captured from the wild as a baby and brought to live with humans. However, the total population is … [30] The conservation of the western lowland gorilla has been made a priority by many organizations. 5 to 6 feet. [27] Gorillas will climb trees up to 15 meters in height in search of food. Some grou… [44] Individual characteristics such as age, sex, personality and individual histories are essential in understanding that stressors will affect each individual gorilla and their welfare differently. Two of the younger females were able to fill the buckets with water. ", "Origin of the HIV-1 group O epidemic in western lowland gorillas", "How Ebola Impacts Genetics of Western Lowland Gorilla Populations", "Gorilla diet protects heart: grains of paradise", Western Lowland Gorilla Conservation in Gabon: Fernan-Vaz Gorilla Project, Oklahoma City Zoo: Western Lowland Gorilla, Astonishing’ gorilla discovery in Republic of Congo, https://en.wikipedia.org/w/index.php?title=Western_lowland_gorilla&oldid=1000972749, IUCN Red List critically endangered species, Creative Commons Attribution-ShareAlike License, This page was last edited on 17 January 2021, at 16:59. [19], Another example of gorillas' significant intelligence is their ability to comprehend simple sign language. Western lowland gorillas may have a more brownish coloration. rain forest. It is common for non-human primates kept in captivity to exhibit behaviors deviating from the normal behavior observed of them in the wilderness. Deforestation and logging allowed for the creation of roads which allowed hunters to hunt deeper into the forest, increasing the amount of poaching and bushmeat trade in the area. The WCS is also working in Congo and surrounding countries to limit the bush meat trade by enforcing laws and hunting restrictions and also helping the local people find new sources of protein. "Ranging and social structure of lowland gorillas in the Lope Reserv, Gabon." Furthermore, in 2013, a study was conducted in order to better understand the genetic variation in gorillas by using reduced representation sequencing. The western lowland gorilla (Gorilla gorilla gorilla) is one of two subspecies of the western gorilla (Gorilla gorilla) that lives in montane, primary and secondary forest and lowland swampland in central Africa in Angola, Cameroon, Central African Republic, Republic of the Congo, Democratic Republic of the Congo, Equatorial Guinea and Gabon. The Wildlife Conservation Society (WCS) has been working with the local community in the Congo Basin to establish wildlife management programs. Range Nigeria, Central African Republic, Equatorial Guinea, Gaboon, Republic of Congo, Angola, and Demacratic Republic of Congo. Female gorillas do not show signs of pregnancy. Throughout his time in Western Washington, Ivan the Gorilla® was adored by the area’s youth, especially during the Christmas season. [12] They are often found on the ground and are made up of up to 30 gorillas. Western gorillas frequently stand upright, but walk in a hunched, quadrupedal fashion, with hands curled and knuckles touching the ground. The western lowland gorilla is the smallest of the gorilla species. It has been found that female western lowland gorillas participate in non-reproductive sexual behavior in order to increase her reproductive success through sexual competition. [24] The forest of the Republic of Congo is currently considered to host the majority of the western lowland gorilla population. Western lowland gorillas are seed dispersers, which is beneficial to many of the animals in the forest, so their extinction could impact many other animals, which could over time destroy their current ecosystem. Gorillas normally travel 3–5 km (1.9–3.1 mi) per day. Females tend to make bonds with other females in their natal group only, but form strong bonds with males. Western lowland gorillas live in the smallest family groups of all gorillas, with an average of four to eight members in each. This clustering allows pinpointing the probable geographic origins of two of the human virus clades. When ripe fruit is in scarce supply, they eat leaves, herbs and bark. In 2009, a western lowland gorilla at Buffalo Zoological Gardens used a bucket to collect water. Western Lowland Gorilla Gorilla gorilla gorilla. https://www.nationalgeographic.com/animals/mammals/w/western-lowland-gorilla.html. The western lowland gorilla is one of two subspecies of western gorilla (the rare Cross River gorilla being the other) and is the most widespread of all gorillas, inhabiting the dense and remote tropical rainforests of Cameroon, the Central African Republic, the Democratic Republic of Congo, Equatorial Guinea, Gabon, Angola, and the isolated lowland swampy forests of the Republic of Congo on the African continent. There is a correlation between human intervention in the wild with the destruction of habitats and increase in bushmeat hunting. They live in primary and secondary lowland tropical forest at elevations that extend from sea level up to 1,300 meters. Troops are led by one dominant, older adult male, often called a silverback because of the swath of silver hair that adorns his otherwise dark fur. Herbivore. [38], Zoos worldwide have a population of 550 western lowland gorillas, and the Cincinnati Zoo leads the United States in western lowland gorilla births. Great Ape Societies. Young gorillas, from three to six years old, remind human observers of children. The Republic of the Congo has put in place a conservation effort to conserve different species such as chimpanzees, forest elephants and western gorillas from poaching and deforestation. The gorillas were shown to quickly learn about receiving rewards as mistakes made by the gorillas in the beginning of the experiments gradually decreased. [13] In the mid-1970s, researchers turned their attention to communicating with gorillas via sign language. The outbreak was monitored in the Republic of Congo by Magdalena Bermejo and other field-based primatologists, as it also spread to humans through contact with bushmeat. In comparison to the mountain gorilla, th… Infants have a tuft of white hair on their backsides, and older gorillas may get streaks of silver in their hair. Gorilla numbers in the wild are declining at a rapid rate. Their intelligence is displayed through their ability to fashion natural materials into tools that help them gather food more conveniently. Deforestation of this area allows for the trade of bushmeat and even more poaching. [56] Adult male gorillas are prone to cardiomyopathy, a degenerative heart disease.[57]. Females weigh 150 to 300 pounds (113-136 kg). [2], The western lowland gorilla is the smallest subspecies of gorilla but still has exceptional size and strength. Unlike their powerful parents, newborns are tiny—weighing four pounds—and able only to cling to their mothers' fur. [37], Bush meat hunting and timber harvesting in the western lowland gorilla’s habitat have negatively affected the probability of its survival. Conservation groups aim to change that by working with local and national authorities to strengthen penalties for poaching and improve land-use planning to better protect the gorilla’s habitat. Larger groups travel greater distances in order to obtain sufficient food. The leader (the silverback) organizes group activities, like eating, nesting and travelling in their home range. These apes used to live here, but it is possible they are now extinct in this section of their range. Gorillas are herbivorous, primarily feeding on leaves, stems, and fruit. The western lowland gorillas, like many gorillas, are essential to the composition of the rainforest due to their seed distribution. However, these non-reproductive gorillas may prove to be a valuable resource since the use of assisted reproductive techniques aid in the maintaining of genetic diversity in the limited populations in zoos. [33] Surveys conducted by the Wildlife Conservation Society in 2006 and 2007 found about 125,000 previously unreported gorillas have been living in the swamp forests of Lake Télé Community Reserve and in neighboring Marantaceae (dryland) forests in the Republic of the Congo. When challenged by another male, a troop leader will demonstrate his strength by standing upright, throwing things, making aggressive charges, and pounding his huge chest while barking out powerful hoots or unleashing a roar. The children of Madison Elementary in Olympia, WA decided to show their appreciation to Ivan’s friendship in the winter of 1985. The Ebola epizootic in western and central Africa has caused more than 90% mortality rate in western lowland gorillas. The one exception in this area is the Democratic Republic of the Congo. It is the nominate subspecies of the western gorilla, and the smallest of the four gorilla subspecies. [35], In the northeastern part of the Republic of the Congo, even though poaching is illegal, western lowland gorillas are still being hunted for their bushmeat and the young for pets; five percent of the subspecies is killed each year because of this. HIV-1, is composed of four phylogenetic lineages, which at some point in time have independently gone through cross-species transmission of the SIV (simian immunodeficiency virus). [15], Female western lowland gorillas living in a group led by a single male have been observed to display sexual behavior during all stages of their reproductive cycle and during times of non-fertility. The western lowland gorilla (Gorilla gorilla gorilla) is a heavily built primate and is the largest ape. [13] Infants can be dependent on their mother for up to five years. Out of 51 faecal samples from habituated individuals, 25 were shown to have Plasmodium DNA. The average amount of rainfall in the areas where western lowland gorillas typically reside is about 1,500 millimetres a year with the greatest rainfall between the months of August and November. Despite these displays and the animals' obvious physical power, gorillas are generally calm and nonaggressive unless they are disturbed. [5] According to the late John Aspinall a silverback gorilla in his prime has the physical strength of seven or eight Olympic weightlifters, but this claim is unverified. The AFS has determined that western lowland gorillas display a deficit of rare alleles. These gorillas live in thick tropical rainforests, where they find plenty of food for their vegetarian diet. These gorillas favor areas where edible plants are more copious. Double moats separate these habitats and groups. Only two days after they started the more formal routine, Koko started responding consistently with the sign "food" when prompted to. The common food item within fibers are the herbaceous stems. A male standing erect can be up to 1.8 m (5 ft 11 in) tall and weigh up to 270 kg (600 lb). Populations can be found in Cameroon, the Central African Republic, the Democratic Republic of Congo and Equatorial Guinea as well as in large areas in Gabon and the Republic of Congo. By increasing the female’s own reproductive success, she then decreases the reproductive success of others female gorillas, regardless of their reproductive state. Western lowland gorillas, one of the largest living primates, can grow up to six feet tall and over 400 pounds. Western gorillas occur in the lowland tropical rain forests of central west Africa.