Snatching cell phones, picking backpacks... There are more conflicts between monkeys and humans, and it’s not just the monkeys’ fault

"Attention, tourists! If you bring glasses, hats, selfie sticks and other items, please be careful to keep them, as they may be snatched by monkeys!"

At the Uluwatu Temple in Bali, the radio has been reminding tourists to protect their belongings and beware of monkeys that may appear at any time. The monkeys here not only steal people's belongings, but also know which things on humans are more important to them, and then specifically snatch these valuables and use them as bargaining chips.

Tourists who have lost their mobile phones, glasses or a pair of slippers are usually helpless and can only try their best to satisfy the monkeys' demands and offer them their favorite food many times until the monkeys are satisfied. Only then can they get back what belongs to them.

In addition to the sudden snatching of personal belongings, there have been more and more cases of people being scratched and bitten by monkeys in recent years . There have been many news reports of monkeys attacking humans, including macaques in Qianling Mountain and Mount Emei in China, long-tailed macaques and pig-tailed macaques in Thailand, Japanese macaques in Japan, and long-tailed macaques in Bali.

Behind the escalation of human-monkey conflicts, human feeding and close contact are important reasons.

Over-habituation of monkeys

Most of the monkeys involved in these incidents are macaques , the most widespread primate species in the world after humans.

Macaques are medium to large in size, with rich facial expressions that can convey certain emotions and intentions; they live in groups, have complex social structures and organizations, and can learn from each other ; they are very smart, have strong learning and adaptability , and in some areas of Southeast Asia have even learned to live with humans.

They feed on fruits, leaves, shoots, seeds, bark and insects, usually preferring fruits. Many macaques also have cheek pouches on their faces where they can store extra food and then quickly carry it to a safe place to eat.

This monkey's cheek pouches are filled with food. Image credit: TR Shankar Raman

Human food seems to be very attractive to monkeys. These nutritious and easy-to-digest foods are often found in trash cans in human activity areas, in human backpacks, or in human hands. At the same time, many people like to actively feed them. Gradually, the monkeys are less and less afraid of people, or they regard humans as a source of food, and gradually get used to and rely on humans.
This phenomenon is called " over-habituation ," where animals may unintentionally become over-adapted or accustomed to human presence and intervention. In the process, monkeys in some areas have even learned to negotiate with humans. They are very good at judging which items the victim values ​​most and making full use of this information to maximize their own profits.

A monkey in Thailand has become very fat because of human feeding. Image source: Viral Press

Want a phone? Here's a snack!

Tourists' phones, wallets and glasses are the main targets of monkeys at Bali's Uluwatu Temple. Often, temple staff have to intervene to mediate. Bargaining between monkeys, tourists and temple staff often lasts for several minutes, with some negotiations lasting up to 20 minutes.

Bananas? NO! Image source: Nature on PBS

In 2015 and 2016, researchers from Canada and Indonesia worked together to observe more than 2,000 monkey robberies and negotiations, and found that monkeys here prefer to exchange valuable items for raw eggs, bags of fruit and biscuits. For less valuable items such as hairpins and empty camera bags, monkeys usually accept smaller rewards.

The researchers said the monkeys learned these behaviors in their society, and this phenomenon has been passed down for several generations in the local monkey group for at least 30 years. Adult monkeys are more skilled in performing these behaviors, while young monkeys generally take longer to learn and master these behaviors.

Only when you get a snack will you throw away your glasses. Image source: Nature on PBS

The monkeys have very keen observation skills. They may have judged which items may have higher value by observing the behavior and objects held by tourists, or they may have gradually learned to distinguish which items have higher value through trial and error until they found that they could exchange them for more food rewards after stealing certain items.

Image source: Escaping Comfort Zone

Be careful of getting bitten!

In this group of monkeys in Bali, the monkeys have not shown violence or aggression towards humans, but are more adept at snatching items such as glasses, catching people off guard. However, in some places, macaque attacks on humans are not uncommon.

Earlier this year, an Australian family had a violent confrontation with a group of angry monkeys on a beach in Thailand. The family was bitten on the hand by the monkeys while trying to prevent their backpack from being stolen and their children from being attacked.

At the clinic where they were treated, staff said they treated one or two people bitten by monkeys every day.

Image source: Sailing La Vagabonde

In Guizhou's Qianling Mountain, thousands of monkey attacks are reported every year. Staff at the Qianling Mountain Park Management Office said that children are usually the most seriously injured in monkey attacks, and many of the injured are attacked by monkeys when they are in close contact with or feeding the monkeys.

Monkeys and other wild animals can infect humans with serious or even life-threatening diseases. If you are bitten by a monkey or other wild animal, you should wash the wound thoroughly with plenty of soap and water for at least 15 minutes and use an antiseptic solution with antiviral properties (such as povidone-iodine) to prevent infection. At the same time, the victim should also take other appropriate medical measures to prevent rabies, tetanus, and other viral and bacterial infections.

Macaques can also transmit simian herpes B virus to humans. Although the risk of infection in humans is relatively low, once infected, patients may suffer from serious central nervous system problems. In March 2021, a veterinarian in Beijing dissected two dead monkeys. A month later, they developed symptoms such as nausea, vomiting and fever, and finally died in late May.

Be careful when looking directly or yawning!

While over-habituation of wild animals provides tourists with great opportunities to see wild animals, and many animals do not have to worry about going hungry, over-habituation is dangerous for both humans and animals. It can lead to a series of problems such as loss of independent foraging ability, health problems, transmission of diseases to humans, and increased conflicts with humans.

To prevent over-habituation of wild animals, people should try to avoid direct contact with wild animals, follow the code of conduct for viewing wild animals, and avoid feeding wild animals. The International Union for Conservation of Nature recommends that people should keep a distance of 7 meters from wild animals . At the same time, humans should also avoid direct eye contact with monkeys , as this may be perceived as a threat by the monkeys.

Keep your distance from the monkeys, don't look directly at them, and don't feed them. Image credit: Dickelbers

Another danger is that humans often misinterpret monkeys’ expressions, thus provoking them to become aggressive. Studies have found that people have many misconceptions about macaques’ expressions, and even experimental participants who have previously come into contact with macaques still make mistakes in identifying the monkeys’ aggressive, painful, and friendly expressions.
Although some of the macaques' facial expressions are similar to those of humans, the emotional states they express may be completely different. For example, a human smile usually expresses happiness, but a macaque's toothy expression does not indicate happiness or friendliness. For many primates, showing your teeth (even if you yawn), looking down at them, or slapping your hands on the ground can be threatening.

A and B expressions are showing aggression or intimidating the opponent, C and D express pain or submission, E is showing friendliness, and F is calm and neutral. Image source: Reference [5]

At tourist attractions in Morocco, researchers often heard tourists say that the monkeys seemed to be blowing kisses to them, but researchers found that these expressions of monkeys were actually threatening.

Tourists, in turn, often respond by mimicking the monkeys' facial expressions, which usually ends with the monkeys attacking the tourists.

References

[1] McKinney, T. (2024, February 04). Why monkeys attack people – a primate expert explains. Retrieved from https://theconversation.com/why-monkeys-attack-people-a-primate-expert-explains-221547

[2] Leca, J.-B., Gunst, N., Gardiner, M., & Wandia, IN (2021). Acquisition of object-robbing and object/food-bartering behaviors: a culturally maintained token economy in free-ranging long-tailed macaques. Phil. Trans. R. Soc. B, 376(1819), 20190677. doi: 10.1098/rstb.2019.0677

[3] Ratcliffe, R. (2021). Bali's thieving monkeys can spot high-value items to ransom. the Guardian. Retrieved from https://www.theguardian.com/science/2021/jan/14/balis-thieving-monkeys-seek-bigger-ransoms-for-high-value-swag-studyMeacham, S. (2023). Aussie family attacked by monkeys at popular beach in Thailand. 9News. Retrieved from https://www.9news.com.au/world/australian-family-sailing-monkey-attack-monkey-beach-thailand/afe47872-5e26-4d88-abd6-5c7ad3460ccc

[4] Urgent! The number of macaques in Qianling Mountain has exceeded the limit by three times! They have injured people nearly 6,000 times a year. The park is collapsing! . (2020, October 26). Retrieved from https://export.shobserver.com/baijiahao/html/304082.html

[5] Maréchal, L., Levy, X., Meints, K., & Majolo, B. (2017). Experience-based human perception of facial expressions in Barbary macaques (Macaca sylvanus). PeerJ, 5, e3413. doi: 10.7717/peerj.3413

[6] Francis, C. (2023). Bali monkeys' unexpected acts shock tourists. news. Retrieved from https://www.news.com.au/travel/destinations/asia/bali/wild-way-aussies-have-17k-worth-of-stuff-stolen-in-bali/news-story/722919b14279236382f8f614ec23229b

[7] Leca research targets light-fingered Balinese macaque monkeys | UNews. (2024, February 07). Retrieved from https://www.ulethbridge.ca/unews/article/leca-research-targets-light-fingered-balinese-macaque-monkeys

[8] Brotcorne, F., Giraud, G., Gunst, N., Fuentes, A., Wandia, IN, Beudels-Jamar, RC, ...Leca, J.-B. (2017). Intergroup variation in robbing and bartering by long-tailed macaques at Uluwatu Temple (Bali, Indonesia). Primates, 58(4), 505–516. doi: 10.1007/s10329-017-0611-1

[9] Dean, S. (2017). How Wild Monkeys Embraced The Thug Life to Sell Stolen Human Valuables For Food. ScienceAlert. Retrieved from https://www.sciencealert.com/how-wild-monkeys-in-bali-took-to-the-thug-life-to-steal-valuables-and-sell-them-back-for-food

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