In 2012, Cercopithecus roloway was included among the world's 100 most threatened species, in a report by the IUCN Species Survival Commission and the Zoological Society of London.
Most of the observed Roloways are of the same age, which indicates that there is high competition between Roloway individuals for resources and access to mates (Buzzard, 2006).
Roloway monkeys also compete and interact with other species of Cercopithecus monkeys (Magnuson, 2002-2003). It is most common for the vocal Roloway monkeys to call during the morning and the evening, as well as after any disturbances. However, due to hunting by humans, the Roloway monkeys do not call often and quickly run away from humans (Magnuson, 2002-2003). Roloway monkeys are very vigilant and frequently give predator alarm calls, making them a very influential species in the survival of other primates (Goneledé Bi et al., 2013).
Due to overexplotaition by human hunting, the Roloway monkey has been extirpated from the Bia National Park, located in Ghana (Struhsaker, 2008). When sites were surveyed where the Roloway monkey was known to be found, used gun cartridges and wire snares were abundant throughout the region (Wiafe, 2013). The forests of Côte d'Ivoire, a common habitat of the Roloway monkey, showed an increase in the hunting activity of humans. This increase caused extirpation of many species originally found there, including the Roloway monkey (Bene et al., 2012). The Roloway monkey is identified as an easy hunting target by humans because, for a mammal, it is loud and is located up in the trees. Humans can pick them out more easily and can hunt them with less work than other inconspicuous species (Struhsaker, 2008). Also, the few habitats that have been left undeveloped by humans tend to be a crucial location for bushmeat (Schulte-Herbrüggen et al., 2013). Guenons, such as the Roloway monkey, are being unsustainably overexploited for bushmeat by full-time hunters. Again, the Roloway monkey is an easy target because these monkeys are large mammals and easier to hunt (Butynski, 2002). Hunting of the Roloway monkey allows the bushmeat to either be consumed as food by the locals, or sold.
In addition, there is another significant influence on the Roloway monkey population size: deforestation (Bergl, 2011) and accompanying habitat fragementation. The decline of most primates can be attributed, in part, to fragmentation in Guinea due to human activity (Barnes, 2002). Also, the reserves designated to help with conservation efforts may be too small and isolated (Gonedelé Bi et al., 2012).
Due to these human activities, the Roloway monkey has had a decreasing population trend for years. The Roloway monkey is one of the three most endangered monkeys that inhabits the forest of Upper Guinea (Mittermeier, 2007). It is estimated that more than 80% of the Roloway monkey populations have decreased over the last decade (Magnuson, 2002-2003). The Roloway monkey population may have been reduced to a total of 500 individuals within recent years (Goneledé Bi et al., 2013).
When 100 locals in Ghana were interviewed in 2013 to see if they had seen the Roloway monkey, 86% of the participants indicated they had seen the monkey in the past, but not within the last 20 years (Wiafe, 2013). Surveys from 1994, which were completed 20 years ago now, show evidence of Roloway monkeys having a sizable presence in both the Yay Forest Reserve and the Ehy Lagoon, both located in the Côte d'Ivoire. However, more recent surveys from 2004 indicate little to no presence of the monkey in these regions (Mittermeier, 2007).Also, local people state that populations of the Roloway monkeys occur in various reserves in Western Ghana, but researchers have difficulties confirming their presence (Sery et al., 2006).
The Roloway monkey has been included on the list of “The World’s 25 Most Endangered Primates” (Mittermeier et al., 2007). It was previously on the list in 2002, but was taken off in subsequent years. It has currently been placed back on the list as of the 2006-2008 listing (Mittermeier et al., 2007), and remains there today. The Roloway monkey is also endangered according to the IUCN Red List of Threatened Animals (Mittermeier and Konstant, 2001).
The forests of Guinea have been recognized as one of the sites requiring the most conservation efforts due to the high number of endangered and endemic primates that are found there (Magnuson, 2005; Gonedelé et al., 2008). However, as of 2012, no conservation efforts have been made specifically for the Roloway monkey. Actual statistics for the range, and population sizes of the monkey are estimated yet mostly unknown (Bene et al., 2012).
Determining the range of the roloway monkey would aid in the conservation efforts for this species (Magnuson, 2002-2003). The Roloway monkey is sometimes seen as a flagship species, meaning it can be used to garner support for other conservation efforts, as well as for itself (Mittermeier et al., 2007). Also, the Roloway monkey is not known to be conserved at popular zoos; the Edinburgh zoo located in Scotland, for example, maintains most primates except for the Roloway monkey (Young, 1998). Perhaps a population of the monkey could be maintained at a zoo, or conservation center in order to make sure the species does not go completely extinct.
Studies of the Roloway monkey all indicate that it is understudied; more information is needed about the species in order to appropriately protect it. The monkey would benefit from research on its current range, habitat, and ecology. The Roloway monkey is in danger of extinction if no actions are taken to protect the species.
The Roloway monkey belongs to the Anthropoids classification of primates. They are one of eight sub-species of apes and monkeys (Buzzard and Parker, 2012). Roloway monkeys are guenons, the genus of Old World Cercopithecus monkeys, all of which are found in forested ecosystems. The characteristics of inhabiting forest canopies, as Roloway monkeys do, is thought to have developed due to ancestors taking refuge from predators in the forest (Buzzard, 2006; Guschanski et al., 2013). Guenons are known to have a large geographic range, yet are concentrated mostly in western Africa (Guschanski et al., 2013).
The official reported range of the monkey is from western Ghana to the Sassandra River in Côte d'Ivoire, as well as into parts of Guinea (Gonedelé et al., 2008). The official range is agreed upon throughout distribution maps, but no uniform surveying of the area has been done to verify an actual range. There have been rare sightings of the Roloway monkey outside the reported range, further north than indicated, by hunters and other passersby (Campbell et al., 2008). Roloway monkeys share a range with Miss Waldron’s red colobus (Piliocolobus badius waldronae) and the white-naped mangabey (Cercocebus atys lunulatus), particularly in the Tanoé Forest (Gonedelé Bi et al., 2013).
The roloway monkey has been extirpated throughout reserves and national parks in Ghana, such as the Bia National Park, the Cape Three Points Forest Reserve, the Draw River Forest Reserve, and the Nini-Suhien National Park (Magnuson, 2002-2003). Sightings by scientists within the last 10 years have only been recorded in the Kwabre Forest in the southwest corner of Ghana (McGraw, 2000-2006). Roloway monkeys were encountered in Ghana’s Ankasa Resource Reserve one-tenth as frequently as they were encountered in Tanoé Forest (Gonedelé Bi et al., 2013). The forestry staff of the Bia-Goaso Forest in southwestern Ghana have confirmed limited presence of the monkey, despite previous records stating otherwise (Danquah et al., 2012). The Subri River Forest Reserve is one of the largest reservations in the country and the presence of the Roloway monkey has been acknowledged by hunters who have traveled through the area (Buzzard and Parker, 2012). The monkey is also known to be found in parts of Côte d'Ivoire (Mittermeier, 2007). The Tanoé Forest, in Côte d'Ivoire, is the habitat of several endangered and threatened species, including the Roloway monkey. The forest, and surrounding areas, are thought to make up a section of the original habitat range of the monkey (Bene et al., 2012).
Roloway monkeys inhabit mangroves, lowland moist forest, and riverine and gallery forests, located in the Guinean Forest Zone in western Africa (Gonedelé Bi et al., 2013; Wiafe, 2013). They inhabit the upper strata of forests, which indicates niche partitioning, because other species of primate use the lower levels (Buzzard, 2006). The Roloway monkey prefers mature and relatively undisturbed forests, but they can also inhabit secondary forests and occasionally even farmlands (Magnuson, 2002-2003).
The GenBank accession numbers for the Roloway monkey are L35193 (Van der Kuyl et al., 1995) and JQ256923 (Guschanski et al., 2013).
The Roloway monkey is distinctive due to the presence of a sizable white “beard” and white upper section of the brow. Also, they typically have yellow or cream-colored fur on their thighs ( Magnuson, 2002-2003; Mittermeier, 2007). No body measurements have been recorded for the Roloway monkey because an adult male has not been observed within close proximity (Butynski et al., 2009). Sexual diomorphism is not an identified characteristic of the species. One of the few characteristics differing between the sexes is that the males have more prominent canines (Lenglet, 1984). Male Roloway monkeys also have significantly larger skulls and mandibles than female Roloway monkeys (Lenglet, 1984).
Roloway monkeys are frugivore-insectivores, although they prefer seeds (Magnuson, 2002-2003). Frugiove-insectivores consume a diet of primarily fruits and insects. The Roloway monkey is known to typically eat ripe fruit located in the canopies of the forest. They are also known to eat the petioles of leaves of Diospyros, evergreen trees/shrubs (Buzzard, 2006). In addition to fruit, the diet of the Roloway monkey has a substantial amount of “animal matter” (Buzzard, 2006). This “animal matter” includes feces as well as animal remains. However, according to one study, the Roloway monkey eats fruit and foliage more frequently than many other species of monkey (Buzzard, 2006). Also, the males of the species ate a significantly larger amount of fruit than females, who instead chose to eat more animal matter and foliage. Roloway males often eat fruit with vigor, more so than females, because it shows their fellow males that they are alert, and because they are able to harvest and consume fruit more rapidly than they could catch prey (Buzzard, 2006). The consumption of animal matter is mainly by females in order to provide more adequate sustenance to keep up with the nutritional demands of a pregnancy (Buzzard, 2006). During times when there is low fruit accessibility, often May-August, the diet of the Roloway monkey is more skewed toward the other options (Buzzard, 2006).In a study used to identify primary receptors in the mouth for taste, Catarrhini monkeys, including Roloways, identified all of the various tastes as sweet. This might indicate why the Roloway monkey has a high preference for fruit (Buzzard and Parker, 2012).
The Roloway monkey (Cercopithecus roloway) is an endangered species of Old World monkey endemic to tropical West Africa. It was previously considered a subspecies of the Diana monkey (C. diana). The species is classified as Critically Endangered due to habitat loss and their continued hunting because of the bushmeat trade. The Roloway monkey is mainly an arboreal species, for the most part inhabiting forests in Ghana and some reserves in South-Eastern Côte-D'Ivoire. More specifically, studies have shown that C. roloway is primarily concentrated in the Tanoé forest of the Côte-D'Ivoire because of their heavy threats to extinction and lack of habitat. It is still difficult to gather data on wild subjects, as they have low populations in a vast forest, but they are a unique and vanishing species.
Both the Cercopithecus diana and the Cercopithecus roloway were originally categorized under the well-known species group: diana. This categorization meant that the two monkeys were related subspecies. This classification, related species from one another, changed in 2005, when each monkey was to be considered its own species, and treated as such. This differing classification is beneficial to each species in relation to conservation efforts and justifications for necessity of conservation. It can be challenging to find funding for extreme conservation efforts, and when the Cercopithecus diana and the Cercopithecus roloway were considered related subspecies, the urgency for conservation may not have been as great. Individuals can find themselves more willing to support conservation of a unique species rather than a subspecies.
The Roloway monkey is a species of guenon monkeys. In fact, they are the largest of all of the 26 African Cercopithecus.[4] Of this genus, The roloway monkey is most similar to the C. diana. Both of these monkeys share similar physical features as well. They both have dark fur surrounding a majority of their body, with a dark brown-reddish patch on their lower back. The Roloway monkey has a prominent white beard resting under its black chin, and above its dark eyes is a horizontal white stripe of fur, resting directly on its brow bone.[5]
Its face is a dark black, accentuated by the bright white fur covering its shoulders and chest. Roloway Monkeys have a relatively flat skull, and unlike many other primates, they do not have an elongated chin cavity, also referred to as a rostrum. In addition, the nostrils of the monkey are closely set and they angle downwards. Its chest, and throat are bright white, and the monkey has white line of fur that runs along each outer-thigh. On the inside of the thighs, the fur can range from being white, red, brown, or even yellowish. They have exceptionally long tails, longer than the entirety of their body. There are not many body measurements of adult Roloway monkeys, but through analysis and comparison with the Diana species, it is estimated that the Roloway Monkeys body length ranges from 40 cm to 55 cm, and the tails of the monkey range from 50 cm to 75 cm long.[6]
Male monkeys weigh about 5 kg, or 11 pounds. The female Roloway weigh only about 2.5 kg, or 5.5 pounds.[7] The Roloway monkey has a distinct cheek pouch, something that it shares with all cercopithecus monkeys. This patch allows the monkeys to store food such as fruits, nuts and seeds, which are the majority of their diet as they are omnivorous primates. Cercopithecinae monkeys all have opposable thumbs, which are quite well-developed; the Roloway Monkey also has fingernails on all of their fingers.[5] Finally, the Roloway monkey has a long lifespan, similar to that of other primates, ranging from 20 to 30 years.[7]
The species occurs in a small area of eastern Ivory Coast and the forests of Ghana, between the Sassandra and Pra Rivers, and may possibly occur in Burkina Faso and Togo. The Roloway inhabit the canopy of old-growth forests, including gallery forests, in moist-low-lying regions, and avoids but can make use of forests that have been lightly logged. The Roloway monkey cannot live in areas where humans have had a large impact, therefore they only live in secluded, primary forests. Primary forests are ones that have not been majorly affected, and they are quite old and full of unique attributions that can allow for populations of animals and plants to be more stable in the long term. These forests are very lush, containing thick and moist shrubbery that allows for easy hiding. The habitats of the Roloway are very complex, and the terrain is not simple, meaning they have many places to hide and escape view. Small areas of these forests and habitats are used to inhabit the monkeys, and the group sizes of the species tend to be minuscule. The monkeys' instinct to flee combined with the areas they choose to live in, make it very hard to study them or gather any new information on the changes in their population size or behavior.[5] Even when studies were performed where scientists stayed in the area where the monkeys were typically found, the Roloway monkey was only spotted on one occasion. In addition to this, most of the Roloway monkey found are taken to zoos to be kept and observed. This is because their population is so low and there are so few seen in the wild, so the main conservation effort is capturing these animals. In addition, the Roloway is unable to survive in a natural, wild, area that has been largely impacted by humans.[8]
The Roloway monkey is an omnivorous species, meaning they will feed on both plants and animals. This means the primates consume various fruits, flowers, leaves, and even insects. Because insects are included in their primary nutritional consumption, the Roloway can be described as insectivorous, along with being labeled an omnivore. The primates will search for large invertebrates and eat them for sustenance. In addition, the Roloway monkey will consume larvae and eggs of said invertebrates for added nutritional value.[7] They can feed on the plant parts of roughly 130 species of trees, climbers, and epiphytes. Like many omnivores, the Roloway monkey also consumes mature fruit pulp, arthropods, oil-rich seeds, and young leaves.[9]
The diet of the Roloway monkey is one that has been observed for quite some time. It is presumed that the monkey will vary its diet in accordance to the season of the year. This means that the Roloway will eat more fruit, and pulp during the dry season of the year. During the wet season, when more insects are out and available for hunting, the Roloway will consume less fruit and seed, and will act more on its insectivorous urges. The variation in abundance of their food supply is the primary influences of such diet changes, and it is actually quite beneficial for the Roloway to sustain itself of varying food sources.[7] When hunting for their food, the Roloway monkey will look for the most direct path, and may not choose to swing, climb, or jump from branch to branch if it is not the most efficient means of food collection.[10]
The Roloway monkey does not often employ its "fight" instinct, rather it chooses to flee from danger. Typical predators of the Roloway monkey include the leopard, large prey birds, chimpanzees, and other larger species. In order to survive against these predators, the Roloway will use communication techniques such as warning sounds, or even signals, in order to tell the other members of their group that a threat is near, and they must flee to safety. The predators do have an impact on the population of monkeys, but they are not the primary cause for the decline in overall population, and the reason for the critically endangered title the Roloway has been given.[10]
Roloway monkeys typically are diurnally active only, and spend the night sleeping high in the canopy, similar to other primates and mammals. The species forms social groups of around 6-30 individuals, typically with a single male, around 10 females and their offspring. Males may change between groups, while females generally stay with the same group into which they were born. When there are reduced populations of the Roloway, the habits of staying in the same group can impose restrictions on the ability for the species to recuperate.[11] For the monkeys, most of their day is spent searching for food, and in between hunting, during rest time, the monkeys will take time to groom one another, play, and care for their young. This is the primary time for bonds to form and strengthen. The rest period during the day is also a great time for the infants to learn and grow mentally. In addition, the Roloway monkey is social, and will interact with other monkeys that inhabit the same areas.[7] The younger, more juvenile Roloway will not be as outgoing and strong as the adult Roloway. The juvenile will also have more reliance on the adults for learning, and understanding of their surroundings.[12] There is still little known about the species day to day activity, as their population numbers are so low and there is not much scientific research on the roloway.
It is known that many primates have very advanced methods of communicating to one another. The Roloway monkey is no exception, as it has many different types of calls and sounds it will make based on the scenario. The monkey is known to croak, chuckle, shriek, and will even make distinct yelling sounds when it senses a threat, and wants to warn the others in the group. Another frequent call is one that the males of the haram will make. This is known as a gathering call and it lets the females and juveniles of the group know that they should return to their home range, near the male.[12] Verbal communications are not the only forms of communication the Roloway employs. Many individuals will perform physical communications, including facial expressions, posture, hand signals, and even actions.[7] The eyebrows of the monkey can also be a giveaway for the emotion it is trying to portray. Raised eyebrows can be used to show threatening signals. In addition, their eyes are important, as a Roloway that is staring is one that is showing dominance and threats. Finally, they use their mouth and teeth as a way of being either dominant or submissive, and different mouth movements or shapes can mean different things. When showing teeth in a smile, the monkey is usually submissive, but when growling and wide open, with a pushed out jaw, the monkey is aggressing.[13] Within their groups, there are levels of hierarchy, and distinct communication, both physical and verbal, is needed in order to maintain a peaceful structure, and to reduce tension and fighting. This is where grooming becomes so essential, as it allows for stronger bonds and sharing of information to occur.
Much of the information about reproduction for the Roloway monkey is based on knowledge of the closely-related Diana monkey. While they are different species, their reproductive behavior is very similar. The Roloway monkey is polygynous, meaning that one male who acts as a leader in the group. Females go through an Estrous cycle of 30 days, and this cycle can occur at any point in the year. This means that there is not one specific time for breeding, but the male can mate with a female whenever her estrous occurs. Female Roloways normally give birth to a single infant or, rarely, twins, after a gestation period of around six months. The female monkey is the primary caretaker, though siblings or non-related female monkeys may help to care for the newborn.[7] The mother will suckle the infant for about six months, and then it will feed it a more adult-like diet, including fruit, nuts, and seeds.[5] A Roloway monkey reaches maturity at about 3–4 years of age. A young male typically seeks out a new group that he can join or forms a new group in order to reproduce with unrelated females.[7] The lifespan of a Roloway monkey is about 20 years in the wild, while individuals in captivity may live for more than 30 years. Captive Roloway monkeys typically go through hormonal changes that restrict their ability to effectively mate and reproduce, but if the conditions match that of their home habitats, they can reproduce as they would in the wild.[12]
The Roloway monkey is a very threatened species, being labeled as an endangered species by the IUCN in 2008. As the population of the monkeys continued to rapidly decline, and the hunting and habitat loss continued, the species was moved up to critically endangered, meaning conservation is more needed than ever.[7] In addition to this title by the IUCN, the Roloway monkey is one of the top three most threatened monkeys on the west coast of Africa.[13] Other sources have suspected that the Roloway is in fact the top most threatened primate in the entire continent of Africa.[14]
The Roloway require a habitat of a primary forest, also known as an old-growth forest, in order to survive. The issue with this is that such forests are undergoing rapid levels of deforestation for human purposes, and this is causing exceptional levels of habitat loss for so many species, including the Roloway. Ghana, the country that the Roloway have been most frequently spotted, has gone through a drastic loss of close to 90% of its forest land throughout the past 100 years.[15] The reason this loss in habitat is so profound is because the Roloway monkey is not good at adapting to new areas or habitats. It requires very specific characteristics in its environment, and as the monkey started to lose such environment, its population has fallen tremendously.[16] The species is listed as one of "The World's 25 Most Endangered Primates".[17] In fact, it is estimated that there are only around 2,000 living individuals, and their population will continue to decline because of how highly hunters value their quality meat. Roloway monkeys are on the brink of extinction not only because of hunting but because of human expansion. The once expansive forest they inhabited continues to shrink as roadways and transportations areas expand. In addition, much of the forest is being used for farming purposes, making the land inhabitable for the monkey.[18] There are fewer and fewer sightings every year since the 1970s and, recently, many of the areas that the Roloway could be found have recently reported zero sightings.[7]
Not only are their predators such as the chimpanzee, the leopard, and the crowned eagle very dangerous, but the Roloway Monkey is also largely affected by humans. The Roloway monkey is a primary target in Ghana bushmeat trade. The bushmeat trade is massive, accumulating almost 1,000 tons of meat, and selling it in the markets on Ghana's streets. The reason the Roloway monkey is so popular for bushmeat is because they are unique. Also, the monkey tends to make loud noises when communicating, and this can allow for hunters to find their location more easily, thus leading the monkeys to being hunted.[14] Recently, however, it has been found that there are so few Roloway left, that even hunters do not want to seek out the monkeys, as they might not make as much profit because of the time it would take to find one.[7] Not only is hunting an issue, but so is habitat loss. Humans are expanding rapidly, and to get more land for buildings, crops, and other human necessities, people are cutting down areas of the forest that the Roloway tend to inhabit. With less and less area to live in, the monkeys become more threatened by hunting, and they also cannot expand their population as much. Humans are the primary reason for such a low population size because of hunting, increased infrastructure, habitat destruction and habitat fragmentation.[14]
The Roloway monkey is now considered one of the top 25 most critically threatened primates in the entire world. There are conservation efforts that need to be taken immediately in order to save this species. There is great recognition for how threatened the species is, but there is not a lot of action going on. CITES labeled them as a Class A species of the African Convention of Nature and Natural Resources, but there are quite a few issues with policy making in the countries that the Roloway live. Due to these issues, there are not many laws properly enforced against the poaching of this species. There are some small foundations started in areas surrounding the Tanoe forest and other locations the monkeys have been found, but without government help, the organizations probably will not go far. Large conservation programs are trying to aid in the revival of this species, through captive breeding and other methods. Unfortunately, the species has hit a point where this breeding is not extremely successful, as the monkeys do not have anywhere to be released to. Currently, efforts need to be in place to find a new location that the primates could thrive in after breeding programs have allowed for a larger captive population that have the potential to be released[7] In 2020, however, the United Kingdom had a large celebration for the first ever birth of a Roloway monkey in that country. There are current breeding programs all over the world, and while many have not been largely successful, this is a small win. The reason breeding programs have had struggles is because the monkeys can have a difficult time acclimating to one another, and are not entirely willing to breed. There are also so few in captivity, that the breeding is quite selective, as inbreeding depression is unfavorable and could worsen the conservation status of the species.[19]
The Roloway monkey (Cercopithecus roloway) is an endangered species of Old World monkey endemic to tropical West Africa. It was previously considered a subspecies of the Diana monkey (C. diana). The species is classified as Critically Endangered due to habitat loss and their continued hunting because of the bushmeat trade. The Roloway monkey is mainly an arboreal species, for the most part inhabiting forests in Ghana and some reserves in South-Eastern Côte-D'Ivoire. More specifically, studies have shown that C. roloway is primarily concentrated in the Tanoé forest of the Côte-D'Ivoire because of their heavy threats to extinction and lack of habitat. It is still difficult to gather data on wild subjects, as they have low populations in a vast forest, but they are a unique and vanishing species.
