E. patas occur in single-male, multi-female groups for most part of the year. Group size varies widely between 5 – 74 (Chism & Rowell, 1988). Extragroup males live solitary or in all-male groups (Harding & Olson, 1986). Multi-male influxes into heterosexual groups occur during the mating season (Hall, 1965; Harding & Olson, 1986; Struhsaker & Gartlan, 1970). Shy behaviour, low densities, cryptic pelage, and large home ranges makes it hard to observe them in many parts of their natural range (De Jong et al., 2008). In the past, patas monkeys rarely came into conflict with humans, but the growing human population (in Kenya for example) has forced farmers to exploit dryer areas, converting patas habitat into agricultural land (Isbell & Chism, 2007; De Jong et al., 2008). E. patas frequently invades farms, consume produce and are considered pests in some parts of their geographical range, mainly in west Africa. Once this primate looses its fear for humans it can act aggresively towards them when treatened. This can be potentially dangeruous due to disease transmission between primates and humans.
The introduced population of E. patas in Puerto Rico occupies substantially smaller home ranges, varying from 3.72 km² to 15.39 km² (González-Martínez, 1998). González-Martínez (1998) suggests that ‘the resource availability of Puerto Rico is adequate to sustain high densities in a small home range while maintaining a group size structure similar to that found in the natural habitats.’ The Puerto Rican population exhibit territorial behavior, with groups having well established boundaries. Populations occurring in their natural habitats have typically large, highly overlapping home ranges (González-Martínez, 1998).
In Puerto Rico E. patas movement is correlated to the occurrence of their most important food sources: Tamarindus indica, Melicoccus bijugatus, Mangifera indica, Prosopis juliflora, Leucaena leucocephala, and Bourrerria succulent. E. patas feeds most often on fruits, seeds or the seed pods of these trees or shubs. Other items in their diet in Puerto Rico are arthropods and human crops taken from agricultural plots (González-Martínez, 2004; Felix Grana., pers.comm., November 2007).
Principal source:
Isbell, L.A. and Chism, J. 2007. Distribution of patas monkeys (Erythrocebus patas) in Laikipia, Kenya, 1979- 2004. Am. J. Primatol. 2007. Vol. 69, No. 11: 1223-1235.
González-Martínez, J. 1998. The ecology of the introduced patas monkey (Erythrocebus patas) population of southwestern Puerto Rico. Am J Primatol 1998; 45(4):351-363.
De Jong, Y.A., Butynski, T.M. & Nekaris, K.A. 2008. Distribution and conservation of the patas monkey Erythrocebus patas in Kenya. Journal of East African Natural History 97: 83-102.
De Jong, Y.A., Butynski, T.M., Isbell, L.A. & Lewis, C. 2009. Decline in the geographical range of the southern patas monkey Erythrocebus patas baumstarki in Tanzania. Oryx 43: 267-274.
Compiler: National Biological Information Infrastructure (NBII), Felix A. Grana Raffucci, Technical Advisor, Puerto Rico Department of Natural & Environmental Resources & IUCN SSC Invasive Species Specialist Group (ISSG)
Review: Yvonne A. de Jong, Eastern Africa Primate, Diversity and Conservation Program, Nocturnal Primate Research Group, Oxford Brookes University, Nanyuki, Kenya.
Publication date: 2007-11-21
Recommended citation: Global Invasive Species Database (2024) Species profile: Erythrocebus patas. Downloaded from http://www.iucngisd.org/gisd/speciesname/Erythrocebus+patas on 08-12-2024.
In Puerto Rico, E. patas is considered a pest on various levels. They frequently invade fruit farms and raid crops. Their size, strength, and lack of fear for humans renders them a potential threat to humans and domestic animals. They may carry diseases that can be passed on to humans. Additionally, they are voracious omnivores and may have an impact on populations of native plants and small animals (Felix Grana., pers.comm., November 2007). There is not enough information about their role as predators on the local avifauna but it is likely that bird species in the Sierra, including the 'Critically Endangered (CR)' Puerto Rican nightjar (see Caprimulgus noctitherus in IUCN Red List of Threatened Species) and the 'Endangered (EN)' yellow-shouldered blackbird (see Agelaius xanthomus in IUCN Red List of Threatened Species), could suffer from nest predation by exotic species such as E. patas (Aukema et al., 2006).
Physical: An effort to find an efficient way of eradicating wild populations of patas monkeys in Puerto Rico is underway (Felix Grana., pers.comm., November 2007).