Macaca mulatta
(rhesus macaque)

Identity

Preferred Scientific Name

• Macaca mulatta Zimmerman, 1780

Preferred Common Name

• rhesus macaque

Other Scientific Names

• Macaca mulata

International Common Names

• English: rhesus macaques; rhesus monkeys
• Spanish: mono resus
• French: macaque rhésus

Summary of Invasiveness

The rhesus macaque (Macaca mulatta) is native throughout Asia and is considered to have the largest native range of any non-human primate. It has been intentionally and unintentionally introduced in Puerto Rico, South Carolina and Florida, USA. Natural resource impacts of rhesus macaque introductions have included shoreline erosion due to mangrove destruction, reduction of island bird populations due to nest predation and bacterial contamination of water bodies. Rhesus macaques have also caused negative economic impacts through crop destruction in Puerto Rico. Population management in introduced ranges has included euthanasia and trapping and removal.

Taxonomic Tree

• Domain: Eukaryota
•     Kingdom: Metazoa
•         Phylum: Chordata
•             Subphylum: Vertebrata
•                 Class: Mammalia
•                     Order: Primates
•                         Family: Cercopithecidae
•                             Genus: Macaca
•                                 Species: Macaca mulatta

Notes on Taxonomy and Nomenclature

Rhesus macaques are designated as “Chinese-derived” and “Indian-derived”, defined by their region of origin. Chinese-derived rhesus macaques are those specifically from China, and Indian-derived are those from India and surrounding countries; the two designations demonstrate distinct haplotypes (Smith and McDonough, 2005). Taxonomists have proposed ten subspecies on the basis of phenotypic and molecular characteristics, although many primatologists argue subspecies distinctions have been arbitrary (Fooden, 2000). The National Primate Research Center recognizes six subspecies: Macaca mulatta brevicauda, M. m. lasiota, M. m. mulatta, M. m. sanctijohannis, M. m. vestita and M. m. villosa (Cawthorn-Lang, 2005).

Description

Rhesus macaques are Old World primates with brown or grey coats that are typically darker on the lower back and lighter above the waist and on the abdomen. The face and rump are hairless and pinkish in colour. They are sexually dimorphic. Adult males average 53.1 cm (1.74 ft) in height and females average 46.8 cm (1.54 ft). Average weights vary across populations, but males are typically 2-3 kg heavier than females (Maestripieri, 2010). Their movement is quadrupedal but they stand on their hind legs to enhance visibility. Their tails are relatively short and are typically relaxed but can be held up for various behaviours (e.g., dominance displays, breeding).

Distribution

Rhesus macaques are considered to have the largest native range of any non-human primate species (Southwick et al., 1996; Smith and McDonough, 2005). They are found throughout 11 Asian countries, spanning west to Afghanistan, east to the Pacific coast of China, south to central India and Laos, and north to central China. There is also a native population on the island of Hainan, China. The northern limit appears to be restricted by climatic conditions, and the southern is believed to be influenced by interspecific competition (Fooden, 2000).

Distribution Table

The distribution in this summary table is based on all the information available. When several references are cited, they may give conflicting information on the status. Further details may be available for individual references in the Distribution Table Details section which can be selected by going to Generate Report.

History of Introduction and Spread

Introductions for Behavioural Research

In 1938, over 400 rhesus macaques were released on Cayo Santiago, Puerto Rico. The animals were introduced to the 15-ha island for behavioural research and to provide animals for biomedical research. While the animals are no longer used for biomedical research, the colony continues to be maintained for behavioural, physiological, ecological, demographic, and non-invasive biomedical research (Hernández-Pacheco et al., 2013; Hernández-Pacheco et al., 2016). The animals have thrived on the island, where they are provisionally fed daily. Despite the removal of over 4000 animals from 1984 to 2012, the population in 2016 was over 1500 individuals (Anderson, 2016).

Desecheo Island National Wildlife Refuge, Puerto Rico, was historically an important breeding habitat for thousands of breeding pairs of seabirds. A group of 57 rhesus macaques was introduced onto the island in 1966. The purpose of this introduction was to study behavioural adaptations to a novel habitat (Evans, 1989; Engeman et al., 2010). Seabird breeding had begun declining on the island after the introduction of rats in the early 1900s, but completely halted by 1970 due to the added pressure of predation by the macaques on eggs and nestlings (Evans, 1989). Several programmes to remove the macaques were implemented from1977 to 1985 (Evans, 1989). A final removal programme was implemented by the US Fish and Wildlife Service and Island Conservation in 2009 and was believed to be nearing eradication by 2015 (US Fish and Wildlife Service, 2011; US Fish and Wildlife Service, 2015).

Introductions for Biomedical Research

Rhesus macaques are the most frequently used primate species for biomedical research (Hannibal et al., 2017). Historically, the majority of these animals that were used for research were wild caught in India, however this practice was banned in India in 1978 (Crockett et al., 1996; Malik, 1989). As a result, US-based biomedical companies began free-ranging breeding populations on islands to provide animals needed for research. This subsequently led to rhesus macaque populations in Puerto Rico, Florida and South Carolina, USA.

In the 1960s-1970s, rhesus macaques and patas monkey (Erythrocebus patas) were introduced to the islands Cueva and Guayacán, off the southwestern coast of Puerto Rico. These animals escaped to the mainland of Puerto Rico by swimming the narrow channel between the islands and the mainland. Both species established and expanded populations on the mainland and by 2010 were estimated to occupy 600 km² of southwestern Puerto Rico (Engeman et al., 2010). Both species caused extensive agricultural damage due to crop-raiding. The Puerto Rico Department of Natural Resources and Environment and the United States Department of Agriculture began a collaborative project to eliminate the populations through euthanasia in 2008, and by 2014 had euthanized over 2000 patas monkeys and over 1000 rhesus macaques (López-Ortiz, 2016).

Charles River Laboratories, a subsidiary of Bausch and Lomb, introduced over 1300 rhesus macaques on Key Lois, an island in the Florida Keys in 1973. From 1978 to 1980, the company moved over 500 of the animals to Racoon Key, an island approximately 15 km north of Key Lois (Lehman et al., 1994; Johnson and Kapsalis, 1998). Like the introductions in Puerto Rico and South Carolina, the purpose of the introductions to these islands was to provide animals for biomedical research. Populations on both islands grew extensively resulting in destruction of mangroves (Kruer, 1996) and potentially decreased bird populations (Enge et al., 2002). The rhesus macacques were removed between 1999 and 2000 (Anderson et al., 2017).

Over 1400 rhesus macaques were introduced on Morgan Island, South Carolina, in 1979 to establish a breeding colony for biomedical research. The population thrived, reaching nearly 4000 individuals by the late 1980s (Taub and Mehlman, 1989). The colony continues as a source of research animals.

Introductions for Tourism

Rhesus macaques were introduced in to the areas surrounding the Silver River in central Florida, USA, in the 1930s. It was believed the animals would increase tourism in the area. Approximately six additional animals were released in the 1940s. By the 1970s the population was in excess of 150 animals. The land was purchased by the state of Florida and became Silver Springs State Park in 1985. By the mid-1980s there were nearly 400 rhesus macaques in Silver Springs State Park, and others had spread to the forests adjacent to the Ocklawaha River. Trapping was initiated in 1984 and continued intermittently to 2012, during which time approximately 1000 animals were trapped and removed. This practice caused extensive public controversy and was subsequently halted. The population in Silver Springs State Park was estimated to be approximately 115 individuals in 2013 and 175 in 2015, and unknown along the Ocklawaha River (Anderson et al., 2017).

Rhesus macaques were introduced to Titusville, Florida, USA, in 1976 after being released from a tourist attraction. There are records of some trapping and removal, but it is unclear how many individuals were removed. The population was last seen in the area in the early 1990s (Anderson et al., 2017).

Introductions

Risk of Introduction

Rhesus macaques are found in an extensive diversity of habitats, ranging from sea level to over 4000m in altitude. They can persist in humid tropical forests and in cold, mountainous regions. They are also generalist omnivores. Because of their plasticity in habitat and dietary requirements, rhesus macaques could potentially become invasive in all continents excluding Antarctica. Risks of introduction may come from unintentional releases from captivity, including zoos or tourist attractions, the pet trade, and the biomedical industry. As demonstrated in Silver Springs, Florida, rhesus macaques are tolerant of genetic depression, and a founding population of only a few individuals can result in an extensive, invasive population.

Habitat

Given their plasticity in environmental requirements, rhesus macaques have adapted to an extensive diversity of habitats, including: subalpine, temperate, subtropical and tropical forests; semi-desert; swamps; suburban and urban landscapes. Rhesus macaques readily adapt to human-dominated landscapes. Compared to natural areas, rhesus macaque populations in urban areas demonstrate larger group sizes and population densities and smaller home ranges (Fooden, 2000).

Habitat List

Biology and Ecology

Reproductive Biology

Reproduction is seasonal, mating typically in the autumn and winter and birthing in the spring or summer (Fooden, 2000). Mating is sexual and promiscuous. Females typically give birth to a single infant per year. Birth of twins is rare and typically results in low survival rate of the infants (Maestripieri, 2010). In cold climates on the northern extreme of the native range, females sometimes reproduce bi-annually rather than annually. Gestation lasts around 165 days (Fooden, 2000).

Activity Patterns

Rhesus macaques are diurnal. They are both arboreal and terrestrial. They are proficient swimmers, and even infants have been observed swimming. Social grooming is used to establish and reinforce social bonds (Maestripieri, 2010). Home range size averages 0.65 km² in food-provisioned (e.g., urban) populations and 1.96 km² in non or minimally food-provisioned populations (Fooden, 2000).

Population Size and Structure

Rhesus macaques live in matrilineal social groups consisting of adult females and their offspring, a single adult alpha male, and subordinate adult males. Females remain with their natal group their entire lives. Males typically emigrate from their natal group upon reaching sexual maturity, after which they will live in solitude or as part of a bachelor group before joining another social group. Sex ratio within social groups is three females to one male on average. Group size and population density is related to food abundance. Average group size is 32.2 individuals in non or minimally food-provisioned populations and 75 individuals in food-provisioned populations (Fooden, 2000).

Nutrition

The diet is predominately herbivorous, including fruits, leaves, buds and stems. They supplement the diet with animal-based protein sources including small vertebrates, invertebrates, honeycomb and eggs.

Climate

Latitude/Altitude Ranges

Notes on Natural Enemies

In the native range, documented predators have included crocodiles, raptors, canids, leopards, tigers, snakes and sharks (Fooden, 2000).

Means of Movement and Dispersal

Accidental and intentional introductions are associated with the tourism and biomedical industries.

Impact Summary

Economic Impact

Introduced rhesus macaques and patas monkeys (Erythrocebus patas) together caused extensive agricultural damage due to crop-raiding in southwestern Puerto Rico Engeman et al., 2010). During 2002-2006 total economic losses by commercial farmers to monkeys increased from US$1.13 million to over US$1.46 million per year. From this total, the economic losses due to farmers avoiding monkey damage by switching from fruit and vegetable crops to less rewarding land use (primarily hay or pastureland) alone increased from US$490,000 to US$1.33 million per year. In USDA (2008) it is estimated that the two species collectively caused US$300,000 in direct losses and $1 million in management costs in Puerto Rico. Economic costs elsewhere are associated with removal of animals where negative effects have been documented as environmental impacts.

Environmental Impact

In Florida, rhesus macacques introduced to Key Lois and Racoon Key consumed natural vegetation, including new growth of mangroves. The animals were reported to have led to the destruction of over 30 acres of red mangroves (Rhizophora mangle) on Key Lois (Kruer, 1996) and potentially decreased bird populations on Racoon Key (Enge et al., 2002). Legal actions resulted in a court-ordered mandate for the macaques to be removed from the islands. The animals were removed between 1999 and 2000 (Anderson et al., 2017).

An introduced population in Silver Springs State Park, Florida, was documented consuming quail eggs from artificial nests, indicating they may predate eggs of native birds (Anderson et al., 2016).

In South Carolina, tidal creeks surrounding the island were found to have elevated levels of Escherichia coli and faecal coliform as a result of the macaques (Klopchin et al., 2008).

In Puerto Rico, seabird breeding on Desecheo Island National Wildlife Refuge had begun declining after the introduction of rats in the early 1900s, but completely halted by 1970 due to the added pressure of predation by the macaques on eggs and nestlings (Evans, 1989). Observational studies conducted in 1969 and 1970 implicated them in the decline of the nesting populations of the red footed booby (Sula sula) and brown booby (Sula leucogaster) (Evans, 1989).

Threatened Species

Social Impact

Rhesus macaques are the most frequently used primate species in biomedical research. Breeding colonies introduced in South Carolina, Puerto Rico and Florida, USA, have provided thousands of animals for research. All of these islands have documented negative environmental impact.   

Macaques are the natural host of the Herpes B virus. The virus is largely asymptomatic in macaques. The virus is spread by transmission of bodily fluid from an infected individual that is in a phase of actively shedding the virus to an uninfected individual. This can come from bites, scratches, exposure to urine or faeces, or sexual activity. Most macaques carry the virus by adulthood. There are no documented cases of humans contracting the virus from macaques in the wild. In laboratory settings, there have been 50 documented cases of humans contracting the virus from macaques, nearly half of which were fatal (CDC, 2016).

Uses

Rhesus macaques are the most frequently used primate in biomedical research. Populations introduced on islands produce animals for this purpose

Uses List

General

• Botanical garden/zoo
• Pet/aquarium trade
• Research model
• Sociocultural value

Genetic importance

• Test organisms (for pests and diseases)

Human food and beverage

• Meat/fat/offal/blood/bone (whole, cut, fresh, frozen, canned, cured, processed or smoked)

Prevention and Control

Due to the variable regulations around (de)registration of pesticides, your national list of registered pesticides or relevant authority should be consulted to determine which products are legally allowed for use in your country when considering chemical control. Pesticides should always be used in a lawful manner, consistent with the product's label.

In their native and non-native ranges, rhesus macaque populations are controlled through culling, hunting, trapping and sterilization.

Gaps in Knowledge/Research Needs

Additional research is needed on the environmental impacts of introduced rhesus macaques in Florida and Puerto Rico, USA.

Research is needed to further assess the human health threats of the Herpes B virus from rhesus macaques

References

Anderson, C. J., Hostetler, M. E., Johnson, S. A., 2017. History and status of introduced non-human primate populations in Florida., 16(1), 19-36. http://www.bioone.org/loi/sena doi: 10.1656/058.016.0103

Anderson, C. J., Hostetler, M. E., Sieving, K. E., Johnson, S. A., 2016. Predation of artificial nests by introduced rhesus macaques (Macaca mulatta) in Florida, USA., 18(10), 2783-2789. http://link.springer.com/article/10.1007/s10530-016-1195-1

Anderson, C.J., 2016. Ecology and impacts of introduced non-human primate populations in Florida. Gainesville, FL, USA: University of Florida

Cawthorn-Lang, K., 2005. Primate Factsheets: Rhesus macaque (Macaca mulatta) Taxonomy, Morphology, and Ecology. National Primate Research Center: University of Wisconsin – Madison. http://pin.primate.wisc.edu/factsheets/entry/rhesus_macaque

CDC, 2016. B Virus (herpes B, monkey B virus, herpesvirus simiae, and herpesvirus B), Centre for Disease Control and Prevention, USA: Atlanta. . https://www.cdc.gov/herpesbvirus/index.html

Crockett, C.M., Kyes, R.C., Sajuthi, D., 1996. Modeling managed monkey populations: sustainable harvest of longtailed macaques on a natural habitat island, 40(4), 343-360. http://depts.washington.edu/cgfs/ifsp/pdf/TinjilPublications/Modeling%20Managed%20Monkey%20Pop-AJP-1996.pdf

Enge, K.M., Millsap, B.A, Doonan, T.J., Gore, J.A., Douglass, N.J., Sprandel, G.L., 2002. Conservation Plans for Biotic Regions in Florida Containing Multiple Rare or Declining Wildlife Taxa. Tallahassee, Florida, USA,

Engeman, R. M., Laborde, J. E., Constantin, B. U., Shwiff, S. A., Hall, P., Duffiney, A., Luciano, F., 2010. The economic impacts to commercial farms from invasive monkeys in Puerto Rico., 29(4), 401-405. http://www.sciencedirect.com/science/journal/02612194 doi: 10.1016/j.cropro.2009.10.021

Evans, M.A., 1989. Ecology and removal of introduced rhesus monkeys: Desecheo Island National Wildlife Refuge, Puerto Rico, 8(1), 139-156.

Fooden, J., 2000. Systematic Review of the Rhesus Macaque, Macaca mulatta (Zimmermann, 1780). Chicago, Illinois, USA, Field Museum of Natural History, 192pp.

González-Martínez, J., 2004. The introduced free-ranging rhesus and patas monkey populations of southwestern Puerto Rico, 2339-46.

Hannibal, D. L., Bliss-Moreau, E., Vandeleest, J., McCowan, B., Capitanio, J., 2017. Laboratory rhesus macaque social housing and social changes: implications for research., 79(1), e22528. http://onlinelibrary.wiley.com/journal/10.1002/(ISSN)1098-2345 doi: 10.1002/ajp.22528

Hernández-Pacheco, R., Delgado, D.L., Rawlins, R.G., Kessler, M.J., Ruiz-Lambides, A.V., Maldonado, E., Sabat, A.M., 2016. Managing the Cayo Santiago rhesus macaque population: the role of density, 78(1), 167-181. http://europepmc.org/articles/pmc4504838

Hernández-Pacheco, R., Rawlins, R.G., Kessler, M.J., Williams, L.E., Ruiz-Maldonado, T.M., González-Martínez, J., Sabat, A.M., 2013. Demographic variability and density-dependent dynamics of a free-ranging rhesus macaque population, 75(12), 1152-1164. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3920185/

Johnson, R.L., Kapsalis, E., 1998. Menopause in free-ranging Rhesus Macaques: estimated incidence, relation to body condition, and adaptive significance, 19(4), 751-765.

Klopchin, J. L., Stewart, J. R., Webster, L. F., Sandifer, P. A., 2008. Assessment of environmental impacts of a colony of free-ranging rhesus monkeys (Macca mulatta) on Morgan Island, South Carolina., 137(1/3), 301-313. http://springerlink.metapress.com/link.asp?id=102878 doi: 10.1007/s10661-007-9766-3

Kruer, C., 1996. The inside story on the monkey islands of the Florida Keys, 68(10),

Lehman, S., Taylor, L., Easley, S., 1994. Climate and reproductive seasonality in two free-ranging island populations of rhesus macaques (Macaca mulatta), 15(1), 115-128.

López-Ortiz, R., 2016. Statistics about the removal of primates in southwest Puerto Rico from 2008 to January 28 2014. http://drna.pr.gov/historico/oficinas/arn/recursosvivientes/negociado-de-pesca-y-vida-silvestre/division-de-recursos-terrestres-1/t-10-proyecto-control-de-primates-t-10-primates-control-project

Maestripieri, D., 2010. Rhesus macaques. In: Breed, M.D., Moore, J., eds. Encyclopedia of Animal Behavior, volume 3. Oxford, UK, Oxford Academic Press, 70-74. http://primate.uchicago.edu/2010AB-encyclopedia.pdf

Malik, I., 1989. Population growth and stabilizing age structure of the Tughlaqabad rhesus, 30(1), 117-120.

Montague, C.L., Colwell, S.V., Percival, H.F., Gottgens, J.F. , 1994. Issues and Options Related to Management of Silver Springs Rhesus Macaques: Technical Report #49.

Rawlins, R.G. , Kessler, M.J. , 1986. The history of Cayo Santiago colony In: The Cayo Santiago Macaques: History, behavior, and Biology. New York, USA, State University of New York Press,

Smith, D.G., McDonough, J. , 2005. Mitochondrial DNA variation in Chinese and Indian Rhesus macaques (Macaca mulatta), 65(1), 1-25.

Southwick, C.H., Yongzu, Z., Haisheng, J., Liu, Z., Wenyuan, Q., 1996. Population ecology of rhesus macaques in tropical and temperate habitats in China. In: Fa, J.E, DG Lindburg, eds. Evolution and ecology of macaque societies. . Cambridge, UK, Cambridge University Press, 95-105.

Taub, D., Mehlman, P., 1989. Development of the Morgan Island Rhesus Monkey Colony, 8(1), 159-169.

Timmins, R.J. , Richardson, M. , Chhangani, A. , Yongcheng, L. , 2008. Macaca mulatta. The IUCN Red List of Threatened Species. http://www.iucnredlist.org/details/12554/0

US Fish and Wildlife Service, 2011. In: United States Fish and Wildlife Service, Draft environmental assessment for restoration of habitat on the Desecheo National Wildlife Refuge through the eradication of non-native rats https://rd.springer.com/article/10.1007%2Fs10661-007-9766-3?LI=true

US Fish and Wildlife Service, 2015. Draft environmental assessment for restoration of habitat on the Desecheo National Wildlife Refuge through the eradication of non-native rats. https://www.fws.gov/caribbean/refuges/desecheo/desecheo-draft-environmental-assessment.pdf

USDA, 2008. Environmental Assessment: Management of Feral and Free-ranging Patas and Rhesus Monkey Populations to Reduce Threats to Human Health and Safety, Agriculture, Nuisances, and Impacts to Native Wildlife Species in the Commonwealth of Puerto Rico. USDA/Animal and Plant Health Inspection Service, Washington, D.C., 87 pp.

Wellem, C.W, 2014. A review of the management measures of feral macaques in Hong Kong, The Chinese University of Hong Kong.

Xie Yan, Li Zhenyu, Gregg WP, Li Dianmo, 2001. Invasive species in China - an overview. Biodiversity and Conservation, 10(8):1317-1341.

Distribution References

Anderson C J, Hostetler M E, Johnson S A, 2017. History and status of introduced non-human primate populations in Florida. Southeastern Naturalist. 16 (1), 19-36. http://www.bioone.org/loi/sena DOI:10.1656/058.016.0103

González-Martínez J, 2004. The introduced free-ranging rhesus and patas monkey populations of southwestern Puerto Rico., 2339-46.

Klopchin J L, Stewart J R, Webster L F, Sandifer P A, 2008. Assessment of environmental impacts of a colony of free-ranging rhesus monkeys (Macca mulatta) on Morgan Island, South Carolina. Environmental Monitoring and Assessment. 137 (1/3), 301-313. http://springerlink.metapress.com/link.asp?id=102878 DOI:10.1007/s10661-007-9766-3

Rawlins RG, Kessler MJ, 1986. The history of Cayo Santiago colony. In: The Cayo Santiago Macaques: History, behavior, and Biology, New York, USA: State University of New York Press.

Timmins RJ, Richardson M, Chhangani A, Yongcheng L, 2008. Macaca mulatta. In: The IUCN Red List of Threatened Species, http://www.iucnredlist.org/details/12554/0

US Fish and Wildlife Service, 2011. United States Fish and Wildlife Service, Draft environmental assessment for restoration of habitat on the Desecheo National Wildlife Refuge through the eradication of non-native rats., https://rd.springer.com/article/10.1007%2Fs10661-007-9766-3?LI=true

Wellem CW, 2014. A review of the management measures of feral macaques in Hong Kong., The Chinese University of Hong Kong.

Links to Websites

Distribution Maps