Assessing “Monkey see, Monkey do” approaches: Imitation games involving langur call mimics and human-macaque coexistence arms race

Eeb Allay Ooo (1)

Executive Summary

The film Eeb Allay Ooo!” by Prateek Vats and Anurag Kashyap might be fiction, but it sparked a real coexistence question: How do humans and macaques live together in a city like Delhi? Intrigued by the film’s portrayal of langur call mimics as a monkey deterrent, we decided to investigate. What we discovered challenged many of the accepted ideas about urban wildlife management1. Foraying beyond suggesting solutions, we delved into the real-time human-macaque encounters, a fascinating interplay of sensory perception, cultural practices, and the urban environment2. This report chronicles our research, from initial doubts about the effectiveness of mimicking langur calls to a much deeper understanding of what it means to share a city with monkeys and other opportunistic animals3. It is important to note that langur call playbacks effectively deter macaques in areas where these species co-exist, such as the outskirts of Sariska Tiger Reserve (author’s unpublished data).

Introduction

We have been interested in the aspects of human-macaque coexistence since 20173, and how the Municipal Corporation of Delhi (MCD) incorporates trained staff who scare off monkeys by shouting like langurs. The film “Eeb Allay Ooo!” presented a satirical perspective on the daily life of a “langur man,” an individual employed to deter rhesus macaques (Macaca mulatta) from government buildings in Delhi by imitating the appearance and calls of langurs, their natural competitor. It struck a chord with us. But does it solve anything? As Indian ecologists studying the challenges of urban ecosystems shared with commensals and wildlife, we saw the film as a prompt to examine the bigger picture: how do we understand and manage the interactions between humans and animals in our crowded cities4? This report presents our preliminary research findings, which challenge existing assumptions and offer new perspectives on human-macaque coexistence5–8.

The film gives us a platform to develop dialogues with citizens about confronting fundamental questions regarding how we manage fragile ecosystems against anthropogenic impacts radiating far beyond rapidly growing cities9. These thoughts prompted questions like: can we just scare the problem individuals away10? What are the real drivers of conflict? And how do we find a way to coexist in places where the lines between human and animal spaces are increasingly blurred? This preliminary report dives into our research, questioning easy solutions used by state agencies like MCD and exploring the complex world of sensory ecology, human behaviour, and the daily struggle for coexistence in a rapidly evolving urban landscape11.

Recently, life-size langur cutouts were employed as macaque deterrents during G20 Indian Presidential meetings in August and September 202311. While the approaches above indicate that the state has incorporated limited scientific understanding about the effectiveness of using visual and auditory langur mimics as macaque deterrents, the reality is more contextualised and based on the local conditions12. Previously, these two primate species coexisted in and around human habitations, with macaques exhibiting greater tolerance towards human presence. However, with the rise of urbanization, langurs, which also inhabit forests distant from anthropogenic resources, appear to tolerate infrastructure poorly and only survive in villages or temples adjacent to their traditional habitats13,14. Conversely, macaques have been so adaptable and opportunistic that they are rarely found in ecosystems without human food subsidies14. Consequently, their increasing numbers in cities, due to ritual feeding practices by devout Hindus, have led to conflicts where these simians inflict physical injuries, damage property, and disrupt daily life12.

As discovered, macaques can identify patterns in stimuli within the urban environment, which have economic, social, and ecological undertones. For instance, it might be important to understand the social backgrounds of people (native/immigrant to Delhi, and hence, may have a prior history of dealing with the monkey menace in villages) who are trained and employed as langur mimics. Additionally, it is important to consider who the victims of the major monkey menace are. We found that interventions by the Municipal Corporation of Delhi (MCD) that were not informed by scientific evidence yielded little to no results and frequently shifted the problem spatially15. These poorly planned and executed steps to address the monkey menace11 made security guards and the urban poor inadvertent targets (author’s unpublished data).

The Stage is Set – Delhi’s Urban Jungle

Like many cities in South Asia, Delhi is where humans and animals live cheek by jowl3. Ritualistic feeding of animals such as dogs, cows, kites and monkeys is deeply ingrained in cultural practices16. This creates species/population-specific dynamics17, involving constant flows of anthropogenic food sources that can both sustain wildlife populations and exacerbate conflict18. Macaques and langurs, being highly adaptable and intelligent, have learned to exploit these ritual feeding resources, leading to increased interactions (and often, conflicts) with humans12,14.

Methods: From Playback Devices to Plotting Behaviors

The pilot study focused on Dr. B. R. Ambedkar University Delhi (AUD) campus and the surrounding areas. Our methodology involved:

  • Demographic Surveys: Mapping out the macaque population to get a baseline understanding of their numbers and distribution (~ 150 individuals).
  • Playback Experiments: We utilized playback devices to broadcast langur calls (both recorded and human-imitated) and documented the reactions of the macaques. Consider this an ecological sound test, conducted alongside controlled experiments where we introduced individuals wearing the uniformed outfits of MCD trainees/security guards and carrying offensive weapons such as sticks and catapults.
  • Behavioural Observations: We carefully documented macaque behaviours in response to various stimuli, from calls and experimental human presence to food availability. We tracked foraging patterns, social interactions, and signs of aggression.
  • Mapping Cultural Practices: We have been surveying the locality to understand the distribution of ritual feeding sites and human attitudes toward macaques16. This helped us understand how culture influences the urban ecosystem. For example, macaques from the AUD campus periodically travel to the nearby Hanuman Temple to consume fruit offered by devotees.

Preliminary Results: Monkeys See, but Monkeys Don’t Do (Much)

The film’s premise was largely debunked. Our results indicate that langur call playbacks are not an effective deterrent. These findings are consistent with research on the use of predator vocalizations with other species that have no prior history of encounter. Macaques displayed minimal curiosity and appeared largely indifferent to the playbacks.  A heightened curiosity towards the langur call playbacks was observed in younger macaques, who are likely undergoing a steep learning curve in urban environments. This disinterest allowed us to deduce that macaque populations without experiential learning associating langur calls with a potential competitor’s presence would remain unaffected, explaining the ineffectiveness of call mimics. Similarly, future research could explore using life-size langur plush toys in association with auditory cues from playbacks to understand which specific competitor characteristics macaques learn and whether these could be rapidly generalized as learned behaviour. However, it is important to note that the same langur playback experiment yielded different results on the outskirts of the Sariska Tiger Reserve, where these two species coexist. Although there were no langurs visible at the time of the playback experiment in February 2023, the macaques feeding on vegetables spread on the road collected as many carrots as they could carry and climbed the nearest tree to likely avoid a potential confrontation with langurs.

Key Findings:
  • Langur calls had limited efficacy: Macaques exhibited a minimal consistent response to langur call playbacks, both authentic and human-imitated. This suggests that without prior experience of actual competitive risk, the calls hold significance for them only when the caller consistently wears a specific uniform and carries a weapon, such as a stick or catapult. The effect is analogous to attempting to frighten someone with a lion’s roar when they have never encountered a lion.
  • Access to anthropogenic food resources was the primary driver of macaque behaviour and distribution12.
  • Macaques exhibited a dynamic evaluation of risk and reward in their coexistence with humans, which involves interplays of neophobia19 and neophilia20 in response to the spatial-temporal patterns in the availability of anthropogenic food subsidies. Their behaviour is not simply a matter of fear or attraction to novel stimuli but rather a complex assessment that takes into account factors such as location (infrastructure), time of day (human or vehicular traffic), age, sex, and prior experience.

Discussion: An exploration into coexistence

Our research explores the preliminary depiction of langur-macaque interaction that is extensively used as a measure to mitigate conflicts. This situation is depicted in “Eeb Allay Ooo!”. The preliminary research outcomes reveal that human-macaque interactions are shaped by a confluence of factors: sensory ecology, cultural practices, urban landscapes, and the individual experiences of the animals themselves 21–25. These observations have significant implications for how we manage human- wildlife conflict7, encompassing both urban and rural environments and involving animals that are opportunistic scavengers as well as those that are forest-dwelling26,27. We need to focus on:

  • Managing anthropogenic food resources is key to reducing conflict: this will require improving waste management and addressing cultural practices surrounding animal feeding in areas with heightened conflict3,28–31. Additionally, exploring how ritual feeding and human intervention variably affect conflict outcomes based on urbanization and local infrastructure will be valuable. The THINKPAWS research group has explored human attack dynamics as a function of extrinsic factors in the case of black kites nesting in Delhi, which are known to attack nest intruders using their talons 18,32.
  • Understanding the sensory world of macaques: Gaining a deeper understanding of how macaques perceive and navigate their environment using telemetry devices is crucial33. This could inform devising more effective deterrent strategies corresponding to their sensory perceptions12.
  • Promoting coexistence through eco-literacy that corresponds to proximate ecological situations: This would necessitate promoting the need for informed changes to traditional human attitudes (perceptions), beliefs and practices regarding the altered behaviour of macaques inhabiting modern built spaces and behaviours towards macaques. Such aspects of eco-literacy16 require education and outreach to encourage responsible interactions and reduce conflict34.

Conclusion: Shifting Coexistence Narratives

Eeb Allay Ooo! offered a glimpse into a world of urban absurdities of the coexistence arms race35–37, backed by extensively discussed pro-wildlife attitudes of Indians38. However, our research revealed a deeper and more complex reality. Coexistence and the positive to agonistic interactions it encompasses are not about simple solutions or poorly established benchmarks of mimicking nature for wildlife management11. For instance, the use of langurs as macaque deterrents worked until recent past when langurs and macaques coexisted, and the use of captive langurs to chase macaques was not under legal scrutiny. The future of coexistence shall be about understanding the intricate web of interactions that shape life in the urban jungles1,39–41. It is about acknowledging the roles people have in creating these dynamics and taking responsibility for finding sustainable solutions 42.

As researchers familiar with regional socio-cultural undertones, we could develop a deeper understanding of how macaques navigate urban environments to access food resources and how these behaviours impact human lives12. The findings of our research could be pivotal in shaping policies and practices that promote safer, healthier, and more sustainable human- animal interactions in urban environments34. It is an opportune moment to progress beyond conventional approaches to conflict mitigation43 and also to utilize the opportunity to study dynamic and systemic responses to non-humans. Approaches to human-animal coexistence that are scientifically informed and that also utilize regional biocultural characteristics could be a vital step in developing sustainable solutions.

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