The Zanzibar red colobus (''Piliocolobus kirkii'') is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriat ...

red colobus Red colobuses are Old World monkeys of the genus ''Piliocolobus''. It was formerly considered a subgenus within the genus ''Procolobus'', which is now restricted to the olive colobus. They are closely related to the black-and-white colobus monke ...

monkey

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found else ...

Unguja Unguja (also referred to as "Zanzibar Island" or simply "Zanzibar", in grc, Μενουθιάς, Menuthias – as mentioned in The ''Periplus of the Erythraean Sea'') is the largest and most populated island of the Zanzibar archipelago, in Tanza ...

, the main island of the

Zanzibar Archipelago The Zanzibar Archipelago ( ar, أرخبيل زنجبار, sw, Funguvisiwa la Zanzibar) consists of several islands lying off the coast of East Africa south of the Somali sea. The archipelago is also known as the Spice Islands. There are four ...

, off the coast of Tanzania. It is also known as Kirk's red colobus after Sir John Kirk, the

British Resident A resident minister, or resident for short, is a government official required to take up permanent residence in another country. A representative of his government, he officially has diplomatic functions which are often seen as a form of indi ...

of Zanzibar who first brought it to the attention of

zoological Zoology ()The pronunciation of zoology as is usually regarded as nonstandard, though it is not uncommon. is the branch of biology that studies the animal kingdom, including the structure, embryology, evolution, classification, habits, and dis ...

science. It is now classified as an

endangered species An endangered species is a species that is very likely to become extinct in the near future, either worldwide or in a particular political jurisdiction. Endangered species may be at risk due to factors such as habitat loss, poaching and inv ...

and in the mid-1990s was adopted as the

flagship species In conservation biology, a flagship species is a species chosen to raise support for biodiversity conservation in a given place or social context. Definitions have varied, but they have tended to focus on the strategic goals and the socio-economi ...

for

conservation Conservation is the preservation or efficient use of resources, or the conservation of various quantities under physical laws. Conservation may also refer to: Environment and natural resources * Nature conservation, the protection and manageme ...

in Zanzibar. The population is still decreasing, and conservationists are attempting to work with the local government to devise a proper, effective strategy to protect the population and habitat. Challenges include the species' habitat, which is limited to the archipelago. The species has been reclassified three times; it was previously in the genus ''

Colobus Black-and-white colobuses (or colobi) are Old World monkeys of the genus ''Colobus'', native to Africa. They are closely related to the red colobus monkeys of genus '' Piliocolobus''. There are five species of this monkey, and at least eight subs ...

'', then in the genus ''

Procolobus The olive colobus monkey (''Procolobus verus''), also known as the green colobus or Van Beneden's colobus, is a species of primate in the family Cercopithecidae. Its English name refers to its dull olive upperparts. It is the smallest example o ...

'', and later in the genus '' Piliocolobus''.

Evolutionary history and taxonomy

The Zanzibar red colobus, ''Piliocolobus kirkii'', population on Zanzibar, represents a population of red colobus that is believed to have been isolated on the island after sea levels rose toward the end of the

Pleistocene The Pleistocene ( , often referred to as the ''Ice age'') is the geological Epoch (geology), epoch that lasted from about 2,580,000 to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was fina ...

epoch In chronology and periodization, an epoch or reference epoch is an instant in time chosen as the origin of a particular calendar era. The "epoch" serves as a reference point from which time is measured. The moment of epoch is usually decided ...

. Furthermore, it is suggested through mitochondrial analysis, that phylogenetic groups within the red colobus have been genetically isolated from another since the

Pliocene The Pliocene ( ; also Pleiocene) is the epoch in the geologic time scale that extends from 5.333 million to 2.58 Examining cranial morphology has shown that ''P. kirkii'' has diverged from mainland '' Piliocolobus'' to its own species. It has experienced an acceleration in morphological evolution of size which is suggested to be the result of insularity on the island and environmental pressures such as competition, habitat, predation and/or resource availability. There has been no evidence for

population bottleneck A population bottleneck or genetic bottleneck is a sharp reduction in the size of a population due to environmental events such as famines, earthquakes, floods, fires, disease, and droughts; or human activities such as specicide, widespread violen ...

s in the species. The smaller cranium of ''P. kirkii'' in contrast to the mainland colobus monkey, is consistent with Foster's rule (also known as the island rule) in which the original (larger) animal becomes smaller over time when there are limited resources. Males tend to have

pedomorphic Neoteny (), also called juvenilization,Montagu, A. (1989). Growing Young. Bergin & Garvey: CT. is the delaying or slowing of the physiological, or somatic, development of an organism, typically an animal. Neoteny is found in modern humans compared ...

traits which include a shorter face, large orbits and an enlarged

neurocranium In human anatomy, the neurocranium, also known as the braincase, brainpan, or brain-pan is the upper and back part of the skull, which forms a protective case around the brain. In the human skull, the neurocranium includes the calvaria or skul ...

. It is not certain how long ago and where this evolutionary change occurred. Through molecular analyses, it is indicated that ''P. kirkii'' is more closely related to the

Udzungwa red colobus The Udzungwa red colobusUdzungwa Red Colobus.
ARKive. Accessed 2008-07-20

(''P. gordonorum'') compared to other red colobus species. This analysis has also placed the divergence of ''P. kirkii'' from its sister species ''P. godronorum'' at about 600,000 years ago, which actually allows for an older evolutionary age compared to the previous assumption that it had become its own species around the last glacial period. The species has been reclassified twice; it was previously in the genus ''

'', and more recently in the genus ''

'' and then the genus ''Piliocolobus''. An alternative common name is Kirk's red colobus after Sir John Kirk (1832–1922), the

of Zanzibar who first brought it to the attention of

science.

Physical description

This

Old World monkey Old World monkey is the common English name for a family of primates known taxonomically as the Cercopithecidae (). Twenty-four genera and 138 species are recognized, making it the largest primate family. Old World monkey genera include baboons ...

's coat ranges from dark red to black, accented with a black stripe along the shoulders and arms, and a pale underside. Its black face is crowned with long, white hair, and features a distinguishing pink mark on its lips and nose. Also, the Zanzibar red colobus has a long tail used only for balancing — it is not

prehensile Prehensility is the quality of an appendage or organ that has adapted for grasping or holding. The word is derived from the Latin term ''prehendere'', meaning "to grasp". The ability to grasp is likely derived from a number of different orig ...

. Sexual dimorphism is generally decreased in the species, meaning the females have little difference in their body size and colour from their male counterparts. Females usually outnumber the males in their groups. The species has a notably small cranium and rotund body shape, with males potentially reaching over 12 kg and females, 10 kg. In adults, highly differentiated facial features help them to distinguish each other in a group.Jorgensen, Matthew. (2009). "Behavioral Application in Wildlife Photography: Developing a Foundation in Ecological and Behavioral Characteristics of the Zanzibar red colobus Monkey (''Procolobus kirkii'') as it Applies to the Development Exhibition Photography". SIT – Zanzibar Coastal Ecology and Natural Resource Management. The word "colobus" comes from

Greek Greek may refer to: Greece Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group. *Greek language, a branch of the Indo-European language family. **Proto-Greek language, the assumed last common ancestor ...

''ekolobóse'', meaning "he cut short", and is so named because of the significant reduction in size, or complete lack of an opposable thumb in comparison to other primates. To make up for this, they have four long digits that align to form a strong hook, allowing them to easily grasp branches and climb. Locals on the island have called the Zanzibar red colobus ''kima punju'' which means "poison monkey" in Swahili because of their strong smell unlike other monkeys. This has caused people to hold negative views of the monkey and even to say it has an evil influence on trees on which they feed, ultimately killing the trees.

Habitat

The Zanzibar red colobus is found in three forests of the Zanzibar archipelago. It displays a wide habit tolerance, but it is mainly an

arboreal Arboreal locomotion is the locomotion of animals in trees. In habitats in which trees are present, animals have evolved to move in them. Some animals may scale trees only occasionally, but others are exclusively arboreal. The habitats pose nu ...

species and prefers drier areas over wet ones. Its habitats include coastal thickets and coastal rag scrub, but it can also be found in

agricultural Agriculture or farming is the practice of cultivating plants and livestock. Agriculture was the key development in the rise of sedentary human civilization, whereby farming of domesticated species created food surpluses that enabled peopl ...

areas and in

mangrove swamps A mangrove is a shrub or tree that grows in coastal saline or brackish water. The term is also used for tropical coastal vegetation consisting of such species. Mangroves are taxonomically diverse, as a result of convergent evolution in several ...

; the latter provides food year-round. When found in agricultural areas, the monkey is more used to humans and comes closer to the ground. About 1,600 to 3,000 individuals remain, and currently, 50% of the monkeys found on the islands live outside protected zones. The largest and most significant area of protection and habitat for the monkey is in Jozani National Park, which provides of land reserve. It is located on the main island and the populations here have been greatly studied in regards to both their ecology and behavior. Even so, many groups have been found in ''shambas'' (Swahili for "farmland") in close proximity to the park. In these ''shambas'' adjacent to the park, higher densities of the red colobus have been reported living here in more cohesive groups, compared to inside the park reserve. The incidence of some of these monkeys living permanently outside the zone of the protected park reserve can increase the endangerment of the groups. Red Colobus 7

Behavior

The groups consist of up to four adult males and many adult females; typically yielding a 1:2 ratio of males to females. Young of varying ages are also incorporated in the group. The number of monkeys in a group can range from 30 to 50 individuals. The species is a very social animal, and can often be observed playing and grooming during the rest periods between meals. Unlike females, in a group, males actually maintain close bonds, acting together in defense of their group and even in grooming each other. Red Colobus monkey

Feeding

Feeding is also a group activity. It begins to feed in the morning, and is more active during the cooler parts of the day. Loud calls from males indicate the group is ready to move to another tree to feed. This monkey is mainly a foliovore, and on average, half of the leaves consumed are young

leaves A leaf ( : leaves) is any of the principal appendages of a vascular plant stem, usually borne laterally aboveground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", while the leaves, st ...

. They also eat leaf shoots,

seed A seed is an embryonic plant enclosed in a protective outer covering, along with a food reserve. The formation of the seed is a part of the process of reproduction in seed plants, the spermatophytes, including the gymnosperm and angiosper ...

flower A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants (plants of the division Angiospermae). The biological function of a flower is to facilitate reproduction, usually by providing a mechanis ...

s, and unripe

fruit In botany, a fruit is the seed-bearing structure in flowering plants that is formed from the ovary after flowering. Fruits are the means by which flowering plants (also known as angiosperms) disseminate their seeds. Edible fruits in partic ...

. It has also been found eating

bark Bark may refer to: * Bark (botany), an outer layer of a woody plant such as a tree or stick * Bark (sound), a vocalization of some animals (which is commonly the dog) Places * Bark, Germany * Bark, Warmian-Masurian Voivodeship, Poland Arts, e ...

, dead

wood Wood is a porous and fibrous structural tissue found in the stems and roots of trees and other woody plants. It is an organic materiala natural composite of cellulose fibers that are strong in tension and embedded in a matrix of lignin ...

, and

soil Soil, also commonly referred to as earth or dirt, is a mixture of organic matter, minerals, gases, liquids, and organisms that together support life. Some scientific definitions distinguish ''dirt'' from ''soil'' by restricting the former ...

.Nowak K. (2007). "Behavioral flexibility and demography of ''Procolobus kirkii'' across floristic and disturbance gradients: Dissertation for the Degree of Doctor of Philosophy." Department of Biological Anthropology, University of Cambridge. It is one of the few species that do not eat ripe fruits; it has a sacculated

stomach The stomach is a muscular, hollow organ in the gastrointestinal tract of humans and many other animals, including several invertebrates. The stomach has a dilated structure and functions as a vital organ in the digestive system. The stomach i ...

with four chambers specific for breaking down plant materials, however it cannot digest the sugars contained in mature fruits. Because the monkey feeds on young leaves (though not limited to them), there are instances where it consumes

charcoal Charcoal is a lightweight black carbon residue produced by strongly heating wood (or other animal and plant materials) in minimal oxygen to remove all water and volatile constituents. In the traditional version of this pyrolysis process, ...

, which is believed to aid their digestion of the

toxins A toxin is a naturally occurring organic poison produced by metabolic activities of living cells or organisms. Toxins occur especially as a protein or conjugated protein. The term toxin was first used by organic chemist Ludwig Brieger (1849� ...

(possibly

phenol Phenol (also called carbolic acid) is an aromatic organic compound with the molecular formula . It is a white crystalline solid that is volatile. The molecule consists of a phenyl group () bonded to a hydroxy group (). Mildly acidic, it r ...

ic compounds) found in the young leaves of the Indian almond tree and

mango A mango is an edible stone fruit produced by the tropical tree '' Mangifera indica''. It is believed to have originated in the region between northwestern Myanmar, Bangladesh, and northeastern India. ''M. indica'' has been cultivated in Sout ...

tree. The habit of consuming charcoal is thought to be a learned behavior presumably passed on from the mother to her offspring. The presence of charcoal deposits were shown to result in these monkeys being more likely to inhabit areas that had trees as a food source that were rich in phenolics. It has been noted, however, that not all populations on the islands carry out the behavior, but that it is rather mostly done by those who consume more perennial and exotic foliage. Since some populations use mangroves as a source of food, it is natural for the monkey to consume more

sodium chloride Sodium chloride , commonly known as salt (although sea salt also contains other chemical salts), is an ionic compound with the chemical formula NaCl, representing a 1:1 ratio of sodium and chloride ions. With molar masses of 22.99 and 35. ...

(NaCl). Because of this, those populations have been observed to drink water directly from tree-holes, or licking water off of leaves. This innovative behavior shows the adaptation of the monkey to novel ecological and environmental circumstances. In the dry season, one of the staple foods, Indian almond tree, as previously mentioned, drops its leaves and can cause the monkey to go beyond park boundaries in order to extend its feeding range. This puts the already endangered

colobine The Colobinae or leaf-eating monkeys are a subfamily of the Old World monkey family that includes 61 species in 11 genera, including the black-and-white colobus, the large-nosed proboscis monkey, and the gray langurs. Some classifications split ...

at more risk.

Reproduction

Males usually reach sexual maturity at about 3–3.5 years old, while females reach it at about two years old. Females approaching estrous can be easily identified because of the swelling and bright red coloration of the genital area. This signals to males that the given female is ready for mating. Moreover, just prior to mating, males will use their fingers to probe the female's birth canal. This is immediately followed by sniffing the area because

estrogen Estrogen or oestrogen is a category of sex hormone responsible for the development and regulation of the female reproductive system and secondary sex characteristics. There are three major endogenous estrogens that have estrogenic hormonal ac ...

and

progesterone Progesterone (P4) is an endogenous steroid and progestogen sex hormone involved in the menstrual cycle, pregnancy, and embryogenesis of humans and other species. It belongs to a group of steroid hormones called the progestogens and is the majo ...

can be detected by this method, further helping the male conclude if the female is indeed ready to breed. Gestation is about 6 months for colobus monkeys and one female has about 1–2 new-born every two years. Parental care is intense and often, the role is shared by multiple females of the group. It is observed that about 76% of offspring are born between September and December.

Infanticide Infanticide (or infant homicide) is the intentional killing of infants or offspring. Infanticide was a widespread practice throughout human history that was mainly used to dispose of unwanted children, its main purpose is the prevention of resou ...

has also been noted on occasion when a new male joins a given group that has infants. Research has suggested that the ability for dietary expansion, which consuming charcoal partly allows, explains the higher birth rates and densities due to resource availability. Birth rates for those living in mangroves are higher than colobus monkeys living in coral rag forests. There are higher birthing rates between October–December for colobines on

Uzi Island Uzi Island is an island in the south of Zanzibar Zanzibar (; ; ) is an insular semi-autonomous province which united with Tanganyika in 1964 to form the United Republic of Tanzania. It is an archipelago in the Indian Ocean, off the coast ...

and then January–February for those in Kiwengwa, located on the eastern side of the main island. Infant mortality can be significantly high with half of the infants born not reaching more than six months of age. The birth rates themselves, however, are actually decreased in comparison to mainland colobus monkeys and interbirth intervals are longer as well. Research has suggested that this is a consequence of disturbed habitats in which mainland colobi are not so affected.

Communication

The

species have a smaller

larynx The larynx (), commonly called the voice box, is an organ in the top of the neck involved in breathing, producing sound and protecting the trachea against food aspiration. The opening of larynx into pharynx known as the laryngeal inlet is about ...

compared to other members of the

Colobinae The Colobinae or leaf-eating monkeys are a subfamily of the Old World monkey family that includes 61 species in 11 genera, including the black-and-white colobus, the large-nosed proboscis monkey, and the gray langurs. Some classifications s ...

subfamily In biological classification, a subfamily (Latin: ', plural ') is an auxiliary (intermediate) taxonomic rank, next below family but more inclusive than genus Genus ( plural genera ) is a taxonomic rank used in the biological classifica ...

. The male's call is more of an alto or soprano in contrast to the low bass of a male's in

black-and-white colobus Black-and-white colobuses (or colobi) are Old World monkeys of the genus ''Colobus'', native to Africa. They are closely related to the red colobus monkeys of genus '' Piliocolobus''. There are five species of this monkey, and at least eight subs ...

species. The Zanzibar red colobus is non-territorial in nature and as so does not typically make loud, territorial threat calls. Zanzibar red colobus distress and warning calls are the "bark", "chist", or "wheet". One of the loudest calls from the monkey is heard when he expresses his dominance over the group and when checking the sexual status of his females. The call heard most often by people in or near Jozani Forest is the 'alerting signal'. This is an attention-getting call that is derived from the progression call. Chirps and grunts are made when there are changes in the surrounding environment such as changes in weather or animal movement in proximity to the group. With most arboreal animals, there are two different alerting calls, one for when a predator is on land, and another when there is an aerial predator. However, because of the lack of larger

birds of prey Birds of prey or predatory birds, also known as raptors, are hypercarnivorous bird species that actively hunt and feed on other vertebrates (mainly mammals, reptiles and other smaller birds). In addition to speed and strength, these predat ...

in Zanzibar, such calls are not often witnessed. The young, on the other hand, because of their smaller size and vulnerability, do at times make such calls when they see shadows. Because the Zanzibar red colobus is extremely social, it has a specific call for when it is alone for a certain amount of time upon which it feels vulnerable or threatened. The young are typically the ones to make such a call that sounds like a loud scream, but adults are occasionally likely (when deemed necessary) to make some variation of the call as well.

Conservation

A number of factors have contributed to the monkey's endangered status. First, an increase in

deforestation Deforestation or forest clearance is the removal of a forest or stand of trees from land that is then converted to non-forest use. Deforestation can involve conversion of forest land to farms, ranches, or urban use. The most concentrated ...

has resulted in a significant reduction in resources and habitat; second, it is hunted for meat and pet markets. To counteract the decline in population, various attempts have been made to protect the species. In 1974, specimens were moved to Ngezi Forest on Pemba Island to try to re-establish the monkey's population. It had been found, however, that 20 years after the translocation to the island only one group of Zanzibar red colobus was found and with few sightings and interviews with locals, the population was estimated to be between 15 and 30 individuals. Researchers concluded that the group had certainly survived but did not increase in number possibly due to adverse relations with humans. Some locals in Pemba hold superstitions against the monkey because of the idea that it brings bad luck upon farmers. This may explain the reason that they have not significantly grown in population size. On Uzi and

Vundwe Island Vundwe Island is a small uninhabited island in Tanzania. The islet is part of the Zanzibar Archipelago, and is located near the southwestern coast of Unguja. It lies only 300 m south of Uzi Island and it has an area of 1,4 km2. Its elev ...

s, the Zanzibar red colobus is subject to extensive habitat destruction, particularly with coral rag forests. There is also reported poisoning, netting, and disappearance of monkeys as well as other with animals.Nowak K, Perkin A, Jones T. (2009) Update on habitat loss and conservation status of the endangered Zanzibar red colobus on Uzi and Vundwe Islands. Unpublished report for Department of Commercial Crops, Fruits and Forestry, Zanzibar. Various attempts have been made for conservation of the species. One project was with the

World Wildlife Fund The World Wide Fund for Nature Inc. (WWF) is an international non-governmental organization founded in 1961 that works in the field of wilderness preservation and the reduction of human impact on the environment. It was formerly named the W ...

, specifically in

Menai Bay Menai Bay is located on the southwestern coast of Unguja island (Zanzibar Island), in the Zanzibar Archipelago in Tanzania. Geography It is an 8 km wide bay on the Zanzibar Strait of the Western Indian Ocean.GoogleEarth The long coastline ...

which is located just west of Uzi Island. Another funded by the

Wildlife Conservation Society The Wildlife Conservation Society (WCS) is a non-governmental organization headquartered at the Bronx Zoo in New York City, that aims to conserve the world's largest wild places in 14 priority regions. Founded in 1895 as the New York Zoological ...

designated the Zanzibar red colobus as the flagship species in a long-term study on population, human influence, and behaviour. The

African Convention African Convention (french: Convention Africaine, CA) was a political party in French West Africa, originally formed at a meeting in Dakar on 11 January 1957. The CA consisted of the Senegalese Popular Bloc (BPS) of Léopold Sédar Senghor, the ...

has played a role in the conservation of the animal by categorizing it as 'Class A.' According to the document ''African Convention on the Conservation of Nature and Natural Resources'', 'Class A' is described as:

species in Class A shall be totally protected throughout the entire territory of the Contracting States; the hunting, killing, capture or collection of specimens shall be permitted only on the authorization in each case of the highest competent authority and only if required in the national interest or for scientific purposes.''African Convention on the Conservation of Nature and Natural Resources''
, ''Organisation of African Unity'', p. 15.

It has been suggested that an important way to promote conservation of the monkey is to simply spread awareness about it – that it is not a harmful animal and that it can actually be good for the region's economy because it draws tourism. This has been the case on the island of

(Zanzibar). Furthermore, it would be necessary to establish and designate protected zones.

References

External links

*ARKive �
images and movies of the Kirk's red colobus ''(Procolobus kirkii)''Department of Commercial Crops, Fruits & Forestry (DCCFF), Zanzibar
{{Taxonbar, from=Q913807 Zanzibar red colobus Endemic fauna of Tanzania Zanzibar Mammals of Tanzania Endangered fauna of Africa Zanzibar red colobus Zanzibar red colobus Primates of Africa