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Action for Primates

Long-tailed macaques, photo by Sarah Kite

Coexistence with Free-living Non-human Primates

The issue

As human beings expand into and destroy natural habitat, there is a concomitant increase in interactions with non-human primates. Historically, this has been defined as 'conflicts', a pejorative term that is based on an anthropocentric view of the issue. It is important to understand, however, that activities by non-human primates considered undesirable by people are not the result of purposeful behaviour against people. The non-human primates are only trying to survive in an increasingly diminishing and hostile environment due to human activity. They are not 'crop raiding' nor are they 'competing'; rather, they are being forced to overcome their innate fear of people in order to survive by foraging on whatever is available. Our language, therefore, should not only be free of negativity and be sensitive to the plight of the non-human primates, it should also imbue a sense of hope and optimism for resolution that emphasises the interests of all concerned.

In an effort to resolve the problems created by themselves, people will often use methods that are inhumane and ineffective. Large numbers of non-human primates may simply be rounded up and killed. Others may be captured alive and used for research and breeding or for the 'pet' and food trade. Although this may provide a short-term reduction in animal numbers, it is cruel and fails to address the issue over a longer period of time. The large scale trapping and exportation of monkeys for the food and research industries is also inhumane. Moreover, this has been shown to be largely ineffectual in reducing damage to human property and crops or in reducing the number of individuals long-term. For example, despite the trapping and export for research of 10,000 vervet monkeys over a 14 year period in Barbados, this did not have the desired effect of reducing crop foraging, as the population of monkeys remained stable due to the species' high breeding rate [§, §].

Rhesus macaques in Nepal; photo credit Jo-Anne McArthur / We Animals
Rhesus macaques in Nepal
photo credit Jo-Anne McArthur / We Animals

Complicating this issue is the mistaken belief that free-living (wild) non-human primates are a threat to human health due to transmission of diseases. There is also considerable misinformation about what diseases monkeys carry in general and which might be transmissible to human beings, although there is also a significant risk of disease transmission from people to non-human primates in captivity. There is very little likelihood that free-living non-human primates could transmit any disease to human beings, unless they are brought into close contact with people such as being trapped for the research or 'pet' trade or to be killed as food.

Resolving unfavourable interactions humanely

The issue needs to be approached from at least two perspectives. One is changing public behaviour and perception, the other is implementing practical methods that are effective.

Preventive measures: It is essential that people involved with management methods understand that adverse interactions between wild animals such as monkeys and people are usually due to inappropriate behaviour on the part of human beings, not the other animals. Wild animals are typically fearful of human beings. If, however, people feed or in any way tolerate or encourage the presence of the animals, the animals become less fearful. Feeding can also make the monkeys reliant on a human food source (anthropogenic), causing them to spend less time foraging for natural sources of food and can artificially increase 'carrying capacity', causing an increase in reproduction beyond what natural habitat would dictate. It is critical, therefore, that people be taught not to encourage the animals in any way. This includes not only not feeding the animals or having easily-available food sources, but also not making attempts at being 'friendly' with the monkeys.

Educating residents to make changes to their lifestyle will be necessary. Monkey-proofing their trash receptacles and deterring entry into their homes through the use of suitable window screening are essential. Food or garbage must not be allowed to accumulate anywhere the monkeys can have access to it. People must be discouraged from feeding wildlife. For example, in Hong Kong and Singapore, fines are imposed against those people who continue to feed wild monkeys.

A systematic method of scaring away the animals with things like unnatural sounds or the sounds of their predators should be instituted and used consistently every time there is an intrusion. For example, in some communities, specific people are assigned the duty of chasing away monkeys from residential or other areas [§, §]. The same principle can be used for deterring crop foraging [§, §, §]. In some cases, dogs have been used successfully to guard fields of crops or deter monkeys from entering areas of human habitation. Solar powered electric fencing can be economical and effective in reducing access to crops. Another strategy involves the use of laser pointers or taste aversion.

Long-tailed macaques on residential pavement, Mauritius
Long-tailed macaques
residential pavement, Mauritius

Sterilisation: Sterilisation is an effective long-term solution that ensures there will be fewer and fewer monkeys over time. It is increasingly being used by authorities who recognise its importance to humanely and effectively provide long-term resolution [§, §, §, §, §, §, §, §]. It should be understood, however, that sterilisation will take time to reduce the number of monkeys in order to result in reduced interactions. Because of this, people would still have to do what they could to discourage monkeys. Importantly, sterilisation should only be used for finite situations, not as strategy for overall management.

As for the method of sterilisation, because the monkeys are completely free-living, the most effective method would be to remove the ovaries (ovariectomy) of females, tie off their Fallopian tubes (tubal ligation) or remove part of the Fallopian tubes (salpingectomy). Once done, these methods would ensure that the female would not be able to reproduce. Although easier to do, sterilising the males will be less effective than doing the females, whether surgically or with vaccine, as it will only take one fertile male to impregnate perhaps several dozen females.

Another way to sterilise females (and males) is the use of chemical or similar sterilants. One is GonaCon™, a gonadotropin-releasing hormone immunocontraceptive vaccine developed by USDA-APHIS-Wildlife Services. It has been shown to be effective in a variety of species. There is some evidence that it may be effective in non-human primates[§]. It has to be injected into the individual, so trapping is still necessary.

Another is Reversible Inhibition of Sperm Under Guidance (RISUG). This contraceptive was developed for human males, but is being advocated for use in non-human primates. It appears to provide lifelong sterilisation.

As with any sterilisation procedure, a method of permanently marking the animal who has been done has to be instituted in order to prevent duplicative efforts. Also, if a vaccine is used, a means of identifying the animals based on when they were done has to be developed in order to know not only that an individual has been done, but also when it is time to re-vaccinate.

Coexistence: In addition to the above, careful consideration of all the issues may lead to discoveries that allow for reasonable coexistence. For example, in Indonesia, it was found that monkeys and human beings depended on the same native tree and that cultivation of this tree might not only help the ecosystem, it might result in a reduction in crop foraging. In South Africa, crop-foraging baboons could be deterred by planting crops specifically for them some distance from the farm.

Trapping and relocation: This may not be ideal or effective in all situations. Success with this approach depends on having suitable habitat located a sufficient distance away to deter the monkeys from simply returning to the original site. There is no distance that has been shown to ensure their not returning, but perhaps a location at least several kilometres away might be helpful. The area to which the monkeys are to be re-homed would not only have to be suitable for them in terms of food and shelter, it would also have to be free of other similar monkeys, or else they or the other monkeys will simply be chased away. Such a translocation of monkeys took place in India in 1997, when 600 rhesus macaques were successfully moved to different sites following an increase in monkey-human interactions that were deemed unfavourable.

Although there is no easy solution to the problem, a continued commitment by the relevant authorities will be essential in developing a plan that works, is humane and is sustainable. A multi-prong approach is likely to yield the best results.


Cited references:

  1. Adak, Baishali. 2019-04-27. "In injectable contraceptive, forest dept finds a solution to control monkey menace" Hindustan Times. accessed 2019-05-27
  2. Anonymous. 2008-10-29. "Rockets now used to end 'monkey peril'" The China Post.
  3. Anonymous. 2010-01-24. "Farmers turn to man's best friend to guard crops against monkeys" The Mainichi Daily News. accessed 2019-10-26
  4. Anonymous. 2011-02-06. "Himachal Pradesh launches monkey sterilization drive to curb its population" Asian News International. accessed 2019-10-26
  5. Anonymous. 2012-07-31. "Hong Kong has praised the success of its primate birth control program" News.com.au. accessed 2020-12-12
  6. Anonymous. 2014-08-16. "Tackling the monkey problem" Today Online. accessed 2019-10-26
  7. Anonymous. 2016-03-10. "Monkey sterilisation project in Agra" Business Standard. accessed 2019-10-26
  8. Anonymous. 2017-08-21. "Karnataka: Farmers use lasers to scare monkeys away" Bangalore Mirror. accessed 2020-03-13
  9. Anonymous. 2019-08-21. "Don't feed wild animals" Hong Kong Country & Marine Parks. accessed 2020-04-27
  10. Anonymous. 2020-08-20. "'Monkey dogs' and tech keep crop-eating simians at bay in Nagano" The Japan Times accessed 2020-08-23
  11. With the deployment of the dogs, the number of wild monkeys spotted in residential areas has sharply dropped, according to the city. Dogs of any breed can be placed in a five-month training session after a trainer deems them capable. They must learn not to injure people, chase only monkeys and return to their owners when called.
  12. Bisht, Gaurav. 2015-07-21. "Now, solar powered electric fences to keep monkeys away" Hindustan Times. accessed 2019-10-26
  13. Boulton, A.M.; Horrocks, J.A. and Baulu, Jean. 1996-10-01. "The Barbados vervet monkey (Cercopithecus aethiops sabaeus): Changes in population size and crop damage, 1980–1994." International Journal of Primatology 17(5):831-844.
  14. Bunluesilp, Noppawan. 2009-08-21. "No monkey business: Thailand launches primate birth control" Reuters. accessed 2019-10-26
  15. Dascanio, J.J.; Hegler, A.; Hall, E.; Porco, A.; Beierschmitt, A.; Eckery, D.; McCall, J. and Simmonds, I. 2014-10-18. "Efficacy of Gonadotropin-Releasing Hormone (GnRH) Vaccine (GonaCon™) on Reproduction Function in Female Vervet Monkeys (Chlorocebus aethiops)" American Association of Zoo Veterinarians. accessed 2021-07-10
  16. Dittus, W.P.J.; Gunathilake, S. and Felder, M. 2019-04-01. "Assessing public perceptions and solutions to human-monkey conflict from 50 years in Sri Lanka." Folia Primatologica 90(2):89-108.
  17. Hill, Catherine M. and Wallace, Graham E. 2012-09-01. "Crop protection and conflict mitigation: reducing the costs of living alongside non-human primates." Biodiversity and Conservation 21(10):2569-2587.
  18. Horrocks, J.A. and Baulu, J. 1988-01-01. "Effects of trapping on the vervet (Cercopithecus aethiops sabaeus) population in Barbados." American Journal of Primatology 15(3):223-233.
  19. Imam, Ekwal; Yahya, H.S.A. and Malik, Iqbal. 2002-01-01. "A successful mass translocation of commensal rhesus monkeys Macaca mulatta in Vrindaban, India" Oryx 36(1):87-93.
  20. isantraveller. 2016-11-21. "Birth Control – Long-tailed Macaques in Phana" Thai Monkey Forest. accessed 2020-04-20
  21. Kaplan, Bentley S.; O'Riain, M. Justin; van Eeden, Rowen and King, Andrew J. 2011-12-01. "A low-cost manipulation of food resources reduces spatial overlap between baboons (Papio ursinus) and humans in conflict" International Journal of Primatology 32(6):1397-1412.
  22. Nelson, Dean. 2013-11-18. "India's monkeys 'to be put on the pill'" The Telegraph. accessed 2019-10-26
  23. Pebsworth, Paula and Radhakrishna, Sindhu. 2020-04-01. "Using conditioned taste aversion to reduce human-nonhuman primate conflict: A comparison of four potentially illness-inducing drugs" Applied Animal Behaviour Science 225():104948.
  24. Peralta, Gabriella. 2016-04-11. "Local student puts a lid on nuisance monkeys" Gibraltar Chronicle. accessed 2020-04-27
  25. Riley, Erin P. and Fuentes, Agustín. 2011-01-01. "Conserving social–ecological systems in Indonesia: human–nonhuman primate interconnections in Bali and Sulawesi" American Journal of Primatology 73(1):62-74.
  26. Saeki, John. 2011-05-06. "Birth control prescribed for Hong Kong monkeys." PhysOrg.com. accessed 2019-10-26
  27. Sha, John Chih Mun and Hanya, Goro. 2013-06-01. "Diet, activity, habitat use, and ranging of two neighboring groups of food-enhanced long-tailed macaques (Macaca fascicularis)" American Journal of Primatology 75(6):581-592.
  28. Sharma, Reuben. 2011-06-12. "Monkeys and HIV: No evidence of any link." New Straits Times.
  29. Shek, Chung-Tong. 2012-08-12. "Macaque contraceptive program in Hong Kong." International Primatological Society XXIV Congress.
  30. Siong, Lee Gim. 2016-04-04. "One-third of monkeys being culled each year 'too much': MP Louis Ng." Channel NewsAsia. accessed 2020-03-14
  31. It just reduces the troop size for a little while.
  32. Tan, Audrey. 2020-03-26. "Tougher penalties for offences against wildlife" The Straits Times. accessed 2020-04-27
  33. The feeding and release of wildlife has been made illegal islandwide with sweeping changes to the Wild Animals And Birds Act passed in Parliament yesterday that confers greater protection on Singapore's native flora and fauna.
  34. Thakur, Joydeep and Sharma, Vibha. 2017-08-05. "Sterilisation and not relocation solution to contain monkeys in Delhi, say experts" Hindustan Times. accessed 2020-03-13
  35. USDA-APHIS-Wildlife Services. 2017-08-01. "Chapter XI: The Use of GonaCon in Wildlife Damage Management" USDA-APHIS-Wildlife Services. accessed 2021-07-10
  36. van Doorn, Angela C. and O'Riain, M.J. 2020-06-30. "Nonlethal management of baboons on the urban edge of a large metropole" American Journal of Primatology ePub:e23164.
  37. Our results suggest that field rangers are a successful nonlethal method for reducing spatial overlap between baboons and urban areas but that intensive, unsystematic herding of the troop does have measurable impacts on behavior and should be prevented.
  38. Vishnoi, Anubhuti. 2013-11-18. "Govt steps in to check monkey population" The Indian Express. accessed 2019-10-26
  39. Wallace, Graham E. and Hill, Catherine M. 2016-01-01. "Deterring Crop-Foraging Wildlife. Lessons from farms in north-western Uganda" Oxford Brookes University. accessed 2020-04-27
  40. Yu, Pin-Huan; Weng, Chia-Chun; Kuo, Hung-Chih and Chi, Chau-Hwa. 2015-04-01. "Evaluation of endoscopic salpingectomy for sterilization of female Formosan macaques (Macaca cyclopis)" American Journal of Primatology 77(4):359-367.

Uncited references:

  1. Afonso, Eve; Fu, Rong; Dupaix, Amaël; Goydadin, Anne-Claude; Yu, ZhongHua; Callou, Cécile; Villette, Petra; Giraudoux, Patrick and Li, Li. 2021-08-04. "Feeding sites promoting wildlife-related tourism might highly expose the endangered Yunnan snub-nosed monkey (Rhinopithecus bieti) to parasite transmission" Scientific Reports 11(1):15817.
  2. An increasing number of studies have found that the implementation of feeding sites for wildlife-related tourism can affect animal health, behaviour and reproduction. Feeding sites can favour high densities, home range overlap, greater sedentary behaviour and increased interspecific contacts, all of which might promote parasite transmission. In the Yunnan snub-nosed monkey (Rhinopithecus bieti), human interventions via provisioning monkeys at specific feeding sites have led to the sub-structuring of a group into genetically differentiated sub-groups. The fed subgroup is located near human hamlets and interacts with domesticated animals. … These elements suggest that feeding sites might indirectly play a role on parasite transmission in the Yunnan snub-nosed monkey.
  3. Al-Thaqafi, Tareq. 2021-07-01. "Concerns mount as Baboons appear in several neighborhoods of Saudi capital" Arab News. accessed 2021-07-02
  4. Periods of development and economic boom have meant that the baboons' natural habitat has often been invaded. This continuous sabotage over the course of many years – excessive logging, destruction of forests, and the killing of natural predators such as tigers, hyenas, wolves, and lynxes – led to the rise of the "monkey phenomenon" in different regions of the Kingdom. They began to flee from the natural areas in which they lived to agricultural areas, attacking the livelihood of farmers.

    [Ahmed Al-Bouq, supervisor of the national launch program and the research and breeding centers of the National Center for Wildlife, stated that] …killing the animals was not a viable solution, stressing the important issue of maintaining ecological balance.
  5. Anonymous. 2018-02-14. "New FWC rule prohibits feeding of wild monkeys" Florida Fish and Wildlife Conservation Commission. accessed 2021-07-13
  6. When these animals are fed by humans, they often develop a dependency on humans as a source of food and become territorial over the area where feeding occurs. This dependency can lead to increased aggression, which may result in injuries and spread of disease to humans.
  7. Balasubramaniam, Krishna N.; Kaburu, Stefano S.K.; Marty, Pascal R.; Beisner, Brianne A.; Bliss-Moreau, Eliza; Arlet, Malgorzata E.; Ruppert, Nadine; Ismail, Ahmad; Mohd Sah, Shahrul Anuar; Mohan, Lalith; Rattan, Sandeep; Kodandaramaiah, Ullasa and McCowan, Brenda. 2021-08-28. "Implementing social network analysis to understand the socio-ecology of wildlife co-occurrence and joint interactions with humans in anthropogenic environments" The Journal of Animal Ecology.
  8. Male macaques were more likely to co-interact with humans than females. Neither macaques' grooming relationships nor their dominance ranks predicted their tendencies to co-interact with humans.

    Our findings suggest that, in challenging anthropogenic environments, less (compared to more) time-consuming forms of affiliation, and additionally greater social tolerance in less ecologically flexible species with a shorter history of exposure to humans, may be key to animals' joint propensities to take risks to gain access to resources. For males, greater exploratory tendencies and less energetically demanding long-term life-history strategies (compared to females), may also influence such joint risk-taking. From conservation and public health perspectives, wildlife connectedness within such co-interaction networks may inform interventions to mitigate zoonosis, and move human-wildlife interactions from conflict towards co-existence.
  9. Balasubramaniam, Krishna N.; Marty, Pascal R.; Samartino, Shelby; Sobrino, Alvaro; Gill, Taniya; Ismail, Mohammed; Saha, Rajarshi; Beisner, Brianne A.; Kaburu, Stefano S.K.; Bliss-Moreau, Eliza; Arlet, Malgorzata E.; Ruppert, Nadine; Ismail, Ahmad; Sah, Shahrul Anuar Mohd; Mohan, Lalit; Rattan, Sandeep K.; Kodandaramaiah, Ullasa and McCowan, Brenda. 2020-12-15. "Impact of individual demographic and social factors on human–wildlife interactions: a comparative study of three macaque species" Scientific Reports 10(1):21991.
  10. …across all species, males and spatially peripheral individuals interacted with humans the most, and that high-ranking individuals initiated more interactions with humans than low-rankers. Among bonnet macaques, but not rhesus or long-tailed macaques, individuals who were more well-connected in their grooming network interacted more frequently with humans than less well-connected individuals. From an evolutionary perspective, our results suggest that individuals incurring lower costs related to their life-history (males) and resource-access (high rank; strong social connections within a socially tolerant macaque species), but also higher costs on account of compromising the advantages of being in the core of their group (spatial periphery), are the most likely to take risks by interacting with humans in anthropogenic environments.
  11. Barua, Maan; Jadhav, Sushrut; Kumar, Gunjesh; Gupta, Urvi; Justa, Priyanka and Sinha, Anindya. 2021-05-01. "Mental health ecologies and urban wellbeing" Health & Place 69:102577.
  12. Bersacola, Elena; Hill, Catherine M. and Hockings, Kimberley J. 2021-02-25. "Chimpanzees balance resources and risk in an anthropogenic landscape of fear" Scientific Reports 11(1):4569.
  13. Bloomfield, Laura S.P.; McIntosh, Tyler L. and Lambin, Eric F. 2020-04-01. "Habitat fragmentation, livelihood behaviors, and contact between people and nonhuman primates in Africa" Landscape Ecology.
  14. Increased edge density around households, collection of small trees for construction, and foraging and hunting for food in forested habitat significantly increase the likelihood of human-NHP contact.
  15. Chowdhury, Shahrina; Brown, Janine and Swedell, Larissa. 2020-07-31. "Anthropogenic effects on the physiology and behaviour of chacma baboons in the Cape Peninsula of South Africa" Conservation Physiology 8(1):coaa066.
  16. As animals increasingly occupy habitats in proximity to humans, with home ranges a mosaic of natural and anthropogenic landscapes, it becomes imperative from a conservation perspective to understand the impacts of human activities on wildlife. … Such proximity, however, is often accompanied by direct conflict between humans and wildlife, leading to higher stress levels, injuries, mortality and behavioural changes, with detrimental effects on long-term health and fitness. … Taken together, the results of this study highlight the risks associated with ranging in anthropogenic environments and point to the need for a multifaceted approach to studying the negative impacts of human activities on animals so as to better inform conservation practices.
  17. Cunneyworth, Pamela M.K. and Duke, Joshua. 2020-03-04. "Vehicle collisions among four species of monkeys between 2000 and 2018 on a suburban road in Diani, Kenya" International Journal of Primatology 41(1):45-60.
  18. This study highlights the risks of roads for monkeys, and that collision rates vary with species, age class, and, in some species, sex and that rainfall is one factor that affects these rates.
  19. Dhawale, Ashni Kumar; Kumar, M. Ananda and Sinha, Anindya. 2020-09-23. "Changing ecologies, shifting behaviours: Behavioural responses of a rainforest primate, the lion-tailed macaque Macaca silenus, to a matrix of anthropogenic habitats in southern India" PLoS One 15(9):e0238695.
  20. With the uncontrolled expansion of anthropogenic modifications of the environment, wildlife species are forced to interact with humans, often leading to conflict situations that have detrimental effects for both wildlife and humans. … Access to human-origin food, either cooked or packaged, acquired directly from homes or garbage pits, in the human-dominated habitat appeared to significantly reduce active foraging and searching for food…
  21. Dittus, Wolfgang P.J. 2020-12-01. "Shields on Electric Posts Prevent Primate Deaths: A Case Study at Polonnaruwa, Sri Lanka" Folia Primatologica 91(6):643–653.
  22. Estrada, Alejandro; Garber, Paul A.; Mittermeier, Russell A.; Wich, Serge; Gouveia, Sidney; Dobrovolski, Ricardo; Nekaris, K.A.I.; Nijman, Vincent; Rylands, Anthony B.; Maisels, Fiona; Williamson, Elizabeth A.; Bicca-Marques, Julio; Fuentes, Agustin; Jerusalinsky, Leandro; Johnson, Steig; de Melo, Fabiano Rodrigues; Oliveira, Leonardo; Schwitzer, Christoph; Roos, Christian; Cheyne, Susan M.; Kierulff, Maria Cecilia Martins; Raharivololona, Brigitte; Talebi, Mauricio; Ratsimbazafy, Jonah; Supriatna, Jatna; Boonratana, Ramesh; Wedana, Made and Setiawan, Arif. 2018-06-15. "Primates in peril: the significance of Brazil, Madagascar, Indonesia and the Democratic Republic of the Congo for global primate conservation" PeerJ 6:e4869.
  23. Gataro, Tamirat and Tekalign, Wondimagegnehu. 2021-07-01. "The attitude of people towards Anubis baboon (Papio anubis) crop foraging activities in sub-Saharan Africa, southern Ethiopia" Primates; Journal of Primatology 62(4): 563-570.
  24. Hardwick, Jane L.; Priston, Nancy E.C.; Martin, Thomas E.; Tosh, David G.; Mustari, Abdul H. and Abernethy, Kirsten E. 2017-12-01. "Community perceptions of the crop-feeding buton macaque (Macaca ochreata brunnescens): an ethnoprimatological study on Buton Island, Sulawesi" International Journal of Primatology 38(6):1102-1119.
  25. We recommend that efforts to protect Buton macaques focus on education and the use of effective nonlethal mitigation techniques, such as electric fencing.
  26. Hill, Catherine M. 2017-04-01. "Primate crop feeding behavior, crop protection, and conservation" International Journal of Primatology 38(2):385-400.
  27. Here I briefly outline current debates about the use of terms such as human–wildlife conflict and crop raiding and why they are misleading, summarize current knowledge about primate crop foraging behavior, and highlight some key areas for future research to support human–primate coexistence in an increasingly anthropogenic world.
  28. Koirala, Sabina; Garber, Paul A.; Somasundaram, Deepakrishna; Katuwal, Hem Bahadur; Ren, Baoping; Huang, Chengming and Li, Ming. 2021-07-21. "Factors affecting the crop raiding behavior of wild rhesus macaques in Nepal: Implications for wildlife management" Journal of Environmental Management 297:113331.
    Idealist record: !Koirala_34298347
  29. In Nepal, for example, the expansion of monocultures, increased forest fragmentation, the degradation of natural habitats, and changing agricultural practices have led to a significant increase in the frequency of human-macaque conflict. … As human-macaque conflict is one of the most critical challenges faced by wildlife managers in South Asia and Southeast Asia, studies of macaque crop raiding behavior provide an important starting point for developing effective strategies to manage human-macaque conflict while promoting both primate conservation and the economic well-being of the local community.

    Crop type and distance from farm fields to the forest edge affected crop raiding. Planting buffer crops and collective monitoring are recommended to reduce crop loss. A program of natural forest restoration is needed in rural areas of Nepal.
  30. Kuthyar, Sahana; Kowalewski, Martin M.; Roellig, Dawn M.; Mallott, Elizabeth K.; Zeng, Yan; Gillespie, Thomas R. and Amato, Katherine R. 2020-12-12. "Effects of anthropogenic habitat disturbance and Giardia duodenalis infection on a sentinel species' gut bacteria" Ecology and Evolution 11(1):45-57.
  31. Contact with human beings or habitat altered by them may lead to reverse zoonosis and compromise the health of non-human primates.
  32. Leca, Jean-Baptiste; Gunst, Noëlle; Gardiner, Matthew and Wandia, I. Nengah. 2021-03-01. "Acquisition of object-robbing and object/food-bartering behaviours: a culturally maintained token economy in free-ranging long-tailed macaques" Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences 376(1819):20190677.
  33. Around the Uluwatu Temple in Bali, Indonesia, a large free-ranging population of long-tailed macaques spontaneously and routinely engage in token-mediated bartering interactions with humans. These interactions occur in two phases: after stealing inedible and more or less valuable objects from humans, the macaques appear to use them as tokens, by returning them to humans in exchange for food. Our field observational and experimental data showed (i) age differences in robbing/bartering success, indicative of experiential learning, and (ii) clear behavioural associations between value-based token possession and quantity or quality of food rewards rejected and accepted by subadult and adult monkeys, suggestive of robbing/bartering payoff maximization and economic decision-making.
  34. Leith, David Alexander; Mpofu, Buhlebethu Sukoluhle; van Velden, Julia Laura; Reed, Cecile Catharine; van Boom, Kathryn Merle; Breed, Dorothy and Kohn, Tertius Abraham. 2020-12-01. "Are Cape Peninsula baboons raiding their way to obesity and type II diabetes? - a comparative study" Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology 250:110794.
  35. This study provides the first indirect evidence that some Peninsula baboons with a history of raiding human food sources, may be at risk of developing insulin resistance in the wild, with long term implications for population health.
  36. Mansell, Naomi L. and McKinney, Tracie. 2021-08-01. "Interactions Between Humans and Panamanian White-Faced Capuchin Monkeys (Cebus imitator)" International Journal of Primatology 42(4):548-562.
  37. Anthropogenic influence is expanding, threatening primate taxa worldwide. With wildlife tourism a burgeoning industry, understanding human–primate interactions is key in avoiding primate defaunation. We observed interactions between humans and a group of wild Panamanian white-faced capuchin monkeys (Cebus imitator) at Curú Wildlife Refuge, Costa Rica, in June and July, 2019, and compared our findings with findings for the same group in May–October of 2006 and 2007, when the group received more provisioning. ... The reduction in moderate and intense behaviors between studies also suggests that reducing direct provisioning could reduce the frequency and intensity of human–primate interactions in tourist sites.
  38. Marty, Pascal R.; Balasubramaniam, Krishna N.; Kaburu, Stefano S.K.; Hubbard, Josephine; Beisner, Brianne; Bliss-Moreau, Eliza; Ruppert, Nadine; Arlet, Małgorzata E.; Sah, Shahrul Anuar Mohd; Ismail, Ahmad; Mohan, Lalit; Rattan, Sandeep K.; Kodandaramaiah, Ullasa and McCowan, Brenda. 2020-03-01. "Individuals in urban dwelling primate species face unequal benefits associated with living in an anthropogenic environment" Primates; Journal of Primatology 61(2):249-255.
  39. McLennan, Matthew R.; Spagnoletti, Noemi and Hockings, Kimberley J. 2017-04-01. "The implications of primate behavioral flexibility for sustainable human–primate coexistence in anthropogenic habitats" International Journal of Primatology 38(2):105-121.
  40. Primates exhibit behavioral flexibility in anthropogenic habitats in various ways, most commonly documented as dietary adjustments, i.e., incorporation of human foods including agricultural crops and provisioned items, and as differences in activity, ranging, grouping patterns, and social organization, associated with changing anthropogenic factors. … The contributions to this Special Issue include both empirical research and reviews that examine various aspects of the human–primate interface. Collectively, they show that primate behavior in shared landscapes does not always conflict with human interests, and demonstrate the value of examining behavior from a cost–benefit perspective without making prior assumptions concerning the nature of interactions.
  41. Morrow, Kristen S.; Glanz, Hunter; Ngakan, Putu Oka and Riley, Erin P. 2019-12-27. "Interactions with humans are jointly influenced by life history stage and social network factors and reduce group cohesion in moor macaques (Macaca maura)" Scientific Reports 9(1):20162.
  42. Muehlenbein, Michael P.; Dore, Kerry M.; Gassen, Jeffrey; Nguyen, Vy; Jolley, O. Grace and Gallagher, Christa. 2021-07-16. "Travel medicine meets conservation medicine in St. Kitts: Disinhibition, cognitive-affective inconsistency, and disease risk among vacationers around green monkeys (Chlorocebus sabaeus)" American Journal of Primatology e23301.
  43. Despite concern about environmental protection, travelers often underestimate the contribution they may have to disease transmission to other species, as well as the risk of becoming infected themselves. … Results revealed that even though individuals with more positive environmental attitudes were more willing to take steps to mitigate tourism-related disease transmission, they were also more likely to report wanting to touch or feed a monkey/ape. … The human desire for physical contact with other species may be partly the result of biophilia, emotionally arousing events (like contact with exotic species) that can lead to further disinhibition, and social media platforms that provide opportunities for exhibitionism. … Individuals for whom physically interacting with monkeys/apes may be emotionally rewarding may not alter their behavior in response to cognitive means of persuasion; techniques aimed at appealing to emotions may be more effective.
  44. Nandi, Jayashree S.; Rathore, Shravan Singh and Mathur, Bajrang Raj. 2021-01-01. "Transmission of infectious viruses in the natural setting at human-animal interface" Current Research in Virological Science 2:100008.
  45. Critical information on two novel zoonotic viruses is presented, unique Indian macaque Simian Foamy Virus (SFV) and H1N1 Influenza A viruses (IAV)-like virus infecting wild rhesus monkeys from the Rajasthan forests. Monkey bites are quite common in India.

    The data presented here however indicate a reverse transmission of H1N1 IAV from humans to rhesus monkeys…

    Reducing animal-human contact and affordable vaccination are two relevant anti-viral strategies to counteract the spread of infectious zoonotic pathogens.
  46. Pebsworth, Paula A. and Radhakrishna, Sindhu. 2021-07-30. "The costs and benefits of coexistence: What determines people's willingness to live near nonhuman primates?" American Journal of Primatology 83(9):e23310.
  47. We surveyed 794 people co-living with four different primate species–rhesus macaque Macaca mulatta, bonnet macaque Macaca radiata, lion-tailed macaque Macaca silenus, and Hanuman langur Semnopithecus dussumieri–in southern and western India to understand how people perceived the costs and benefits of coexistence. The results of our semi-structured interview study revealed that although tangible costs (i.e., financial losses from primate depredation) primarily drive people's stated tolerance for primate presence, intangible benefits from primates (i.e., their ecological, existence, sentience, and religious values) also critically affect attitudes towards coexistence. Amongst the four species, people associated rhesus macaques with the greatest costs and fewest benefits, lion-tailed macaques with the lowest costs, and bonnet macaques with the highest benefits. People preferred lion-tailed macaques and Hanuman langurs more than bonnet and rhesus macaques, and affection for a species shaped how people viewed costs accruing from the species. People's preferences for species were influenced by their existence, ecological, and sentience values more than their religious value. We suggest that intangible benefits influence people's fondness for a primate species and this, in turn, shapes how people perceive costs resulting from the species. Hence strengthening people's perceptions of the intangible benefits they receive from primate species will improve human tolerance for living near primates. We argue that there is a need to understand the context of human–primate conflicts beyond the cost aspects and focus on the benefits to improve human–primate coexistence.
  48. Rajput, Abhinav. 2018-07-09. "Hardlook – Man vs Monkey: Born to be wild" The Indian Express. accessed 2021-07-11
  49. Riley, Erin P.; Shaffer, Christopher A.; Trinidad, Joshua S.; Morrow, Kristen S.; Sagnotti, Cristina; Carosi, Monica and Ngakan, Putu Oka. 2021-03-10. "Roadside monkeys: anthropogenic effects on moor macaque (Macaca maura) ranging behavior in Bantimurung Bulusaraung National Park, Sulawesi, Indonesia" Primates; Journal of Primatology ePub.
  50. The macaques appear to be attracted to the road because it presents opportunities to obtain palatable and energy-dense foods. Our results indicate that moor macaques are able to flexibly adjust their ranging behavior in response to anthropogenic impacts. However, given the risks of being in proximity to roads and humans, management of this emerging human-macaque interface is needed.
  51. Sánchez-Murillo, Francisco and Arguedas, Randall. 2021-07-28. "Blood analytes of electrocuted mantled howler monkeys (Alouatta palliata) in the Nicoya peninsula of Costa Rica" Journal of Medical Primatology.
  52. Several species of Costa Rican wildlife are suffering terrible injuries along the power lines in rural areas of the country due to the increasing human development in rural areas, but this has also brought the problem of poorly designed electric infrastructure, where arboreal mammals find their normal tree routes cut down so that the only way for them to cross is on the power lines where they can get electrocuted.
  53. Sengupta, Asmita and Radhakrishna, Sindhu. 2020-06-01. "Factors Predicting Provisioning of Macaques by Humans at Tourist Sites" International Journal of Primatology 41(3):471-485.
  54. Provisioning of primates is a common behavior that humans engage in at these sites. … People were driven to feed macaques by the desire to observe them closely, concern over decreasing food resources for wildlife, and religious affinities.
  55. Sengupta, Asmita and Radhakrishna, Sindhu. 2018-10-01. "The Hand That Feeds the Monkey: Mutual Influence of Humans and Rhesus Macaques (Macaca mulatta) in the Context of Provisioning" International Journal of Primatology 39(5):817-830.
  56. We found that the macaques' consumption of natural resources and dietary diversity decreased, and they spent more time in human-modified habitats when provisioned food was available. We also found that particular behaviors of the provisioned macaques stimulated provisioning by humans. Our findings show that provisioning influences macaque feeding ecology and habitat use, and that the behavior of the macaques themselves drives people to provide them with food subsidies, illustrating a complex web of interactions between the sympatric species.
  57. Sharma, S. 2016-03-01. "Human-Rhesus macaque conflict at Pumdivumdi/Tallokodi, Pokhara, West Nepal" . accessed 2020-04-25
  58. Springer, Justin H.A. 2020-01-01. "Best Practices in Green Monkey Deterrence: A Manual for Farmers in Barbados." The Ministry of Environment and National Beautification, Barbados. 59pp.
  59. The aim of the manual is to describe methods that farmers can try to reduce crop damage, not to describe methods to reduce monkey numbers.

    The Green monkey (Chlorocebus sabaeus) was first introduced to Barbados in the early 1600's, and an Act for Destroying Wild Monkeys and Raccoons was passed for the first time in 1680 because of their crop raiding behaviour. The monkey population has risen and fallen several times since the bounty was introduced, but a recent increase in crop raiding activity has been creating significant challenges for the agricultural sector.
  60. Walton, Ben J.; Findlay, Leah J. and Hill, Russell A. 2021-01-03. "Insights into short- and long-term crop-foraging strategies in a chacma baboon (Papio ursinus) from GPS and accelerometer data" Ecology and Evolution 11(2):990-1001.
  61. Crop fields were avoided for most of the year, suggesting that fields are perceived as a high-risk habitat. When field visits did occur, this was generally when plant primary productivity was low, suggesting that crops were a “fallback food”. All recorded field visits were at or before 15:00. Activity was significantly higher in crop fields than in the landscape in general, evidence that crop-foraging is an energetically costly strategy and that fields are perceived as a risky habitat. In contrast, activity was significantly lower within 100 m of the field edge than in the rest of the landscape, suggesting that baboons wait near the field edge to assess risks before crop-foraging. Together, this understanding of the spatiotemporal dynamics of crop-foraging can help to inform crop protection strategies and reduce conflict between humans and baboons in South Africa.
  62. Zhao, Xumao; Li, Xinrui; Garber, Paul A.; Qi, Xinzhang; Xiang, Zuofu; Liu, Xiang; Lian, Zhongmin and Li, Ming. 2021-08-01. "Investment in science can mitigate the negative impacts of land use on declining primate populations" American Journal of Primatology 83(8):e23302.
  63. We found that 16 of 21 (76%) primate species in China, for which data are available, have experienced a population decline over the past 35 years. Factors contributing most to primate population decline included human poverty and the conversion of natural habitat to cropland. In contrast, the five species of primates that were characterized by recent population increases were the subjects of substantial government research funding and their remaining distribution occurs principally in protected areas (PAs).