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A multi-site field study led by Ardiantiono, Tim S. Jessop, Deni Purwandana, Achmad Ariefiandy, Claudio Ciofi, M. Jeri Imansyah, and Maria Rosdalima Panggur — conducted across Komodo National Park by the Komodo Survival Program — systematically measured how varying levels of human activity reshape Varanus komodoensis behaviour, physiology, and population structure. This is an original editorial summary prepared by the Komodo Guide team; readers are encouraged to consult the primary source directly for full methodology and data.
Table of Contents
- Quick Facts
- Paper Overview
- Behavioural Shifts Across Activity Levels
- The Ranger Feeding Era: Loh Liang & Loh Buaya
- Body Condition & Demographic Consequences
- Management Implications
- Myths vs Facts
- Key Takeaways
- Frequently Asked Questions
- Sources & Further Reading
Quick Facts
| Detail | Information |
|---|---|
| Full citation | Ardiantiono, Jessop, T.S., Purwandana, D., Ariefiandy, A., Ciofi, C., Imansyah, M.J., Panggur, M.R. (2018). "Effects of human activities on Komodo dragons in Komodo National Park." Biodiversity and Conservation, 27(13): 3329–3347. DOI: 10.1007/s10531-018-1601-3 |
| Published | 30 July 2018 |
| Lead institutions | Komodo Survival Program (Denpasar, Bali); Deakin University (Australia); University of Florence (Italy) |
| Study design | Multi-site comparison across high, low, and negligible human-activity zones within Komodo National Park |
| Phenotypic measures | Behaviour (initial response type, approach distance), body mass, body condition index |
| Demographic measures | Age structure, sex ratio, survival probability, population density |
| Core finding | High human-activity sites produce habituated, better-conditioned, adult-biased dragons that depend on anthropogenic food subsidies |
| Open access | doi.org/10.1007/s10531-018-1601-3 |
Paper Overview
Wildlife populations inside national parks are rarely isolated from human influence. Even where direct hunting or habitat clearance is prohibited, the steady presence of tourists, rangers, and support infrastructure creates a gradient of anthropogenic disturbance that can reshape animal behaviour, physiology, and demography in ways that are easy to overlook but difficult to reverse. In 2018, a team from the Komodo Survival Program (KSP) published the first comprehensive, multi-site study to quantify exactly how this gradient operates within Komodo National Park.
The paper — Ardiantiono, Jessop, T.S., Purwandana, D., Ariefiandy, A., Ciofi, C., Imansyah, M.J., & Panggur, M.R. (2018), "Effects of human activities on Komodo dragons in Komodo National Park," Biodiversity and Conservation 27(13): 3329–3347 — combined behavioural observations, morphometric measurements, and mark-recapture demographic surveys across sites representing three distinct levels of human activity: high-activity tourism and settlement zones, low-activity peripheral areas, and remote sites with negligible human presence. By comparing Varanus komodoensis responses across this gradient simultaneously, the authors could isolate the signal of human influence from ecological variables such as prey availability and habitat structure.
The study is notable for its integrated scope. Most previous research on Komodo dragons and tourism had examined either behaviour or demography in isolation. By measuring both phenotypic and demographic attributes within a single analytical framework, Ardiantiono and colleagues were able to show that the two dimensions are linked: behavioural habituation in high-activity areas turns out to be a surface expression of deeper, ecologically consequential changes in body condition, survival, and population age structure.
Editorial Note
This page focuses specifically on the Ardiantiono et al. (2018) paper and its measured, site-level findings. Readers interested in broader population trends across the species range should see our review of Ariefiandy et al. (2021). Wider discussions of tourism management and ecotourism revenue are covered in our conservation section.
Behavioural Shifts Across Activity Levels
At the core of the paper is a systematic assessment of how V. komodoensis individuals respond when they encounter humans, and how that response varies with the intensity of human activity at their home site. The researchers recorded each dragon's initial reaction on a spectrum ranging from avoidance and retreat at one extreme, through neutral indifference, to approach and proximity-seeking at the other. They also measured the distance at which dragons first reacted to an approaching observer — a standard metric of wariness used across wildlife habituation studies.
The contrast between zones was pronounced. Dragons at sites with negligible human activity — the outer reaches of the park where no permanent tourism infrastructure exists — behaved in a manner consistent with a wild predator treating an unfamiliar large mammal as a potential threat. They registered human presence at greater distances, broke from resting positions earlier, and were more likely to move away than to remain stationary or orient toward the observer. This baseline wariness aligns with the natural risk-assessment behaviour documented in apex predators unfamiliar with humans.
At high-activity sites — principally the two main visitor centres of Loh Liang on Komodo Island and Loh Buaya on Rinca Island — the picture was strikingly different. Dragons at these sites showed markedly reduced flight distances and a substantially higher proportion of neutral to approach responses. Far from being alarmed by the presence of people, they were often indifferent, and in some cases moved toward groups of observers, apparently associating human proximity with food opportunity rather than danger. The low-activity sites, as expected, fell between these extremes, with intermediate flight distances and a mix of avoidance and neutral responses.
This pattern is consistent with individual-level and population-level habituation: dragons at high-activity sites have been exposed to human presence consistently enough, and have experienced enough positive reinforcement through food availability near human infrastructure, that the wariness response has been substantially dampened. Importantly, the study found this pattern to hold across age and size classes at the high-activity sites, suggesting that the effect is not limited to a subset of bolder or older individuals but represents a broad phenotypic shift in the local population.
The Ranger Feeding Era: Loh Liang & Loh Buaya
To understand why the habituation at Loh Liang and Loh Buaya is as deep as it is, the study situates the behavioural data within the historical context of supplementary feeding — a practice that was once a central feature of tourism at both sites. For several decades running through the late twentieth century, park rangers at Komodo National Park's main visitor centres conducted scheduled feeding demonstrations in which goats were tethered or killed and presented to dragons in front of assembled tourists. The spectacle of multiple large lizards converging on a carcass simultaneously was a reliable crowd-pleaser, and the practice became tightly woven into the visitor experience and the local economy; communities on nearby islands supplied goats to the park and depended on that market.
The feeding programme at Loh Liang was the more established of the two, operating across a clearing that functioned as an informal amphitheatre. Observers recorded gatherings of up to twenty dragons — spanning subadults to large adults — drawn reliably to the site during feeding sessions. At Loh Buaya on Rinca, a parallel pattern developed, with dragons congregating near the ranger station and visitor facilities on a predictable schedule aligned with tourist activity.
The ecological consequences of this provisioning were significant. Regular feeding caused artificial inflation of dragon numbers at the viewing sites well above what prey availability alone would support. Dragons that might otherwise range widely across the island were anchored near the visitor infrastructure by a predictable food source, compressing home ranges and increasing local densities. Their exposure to human presence at feeding events, repeated over years, progressively eroded the wariness response. By the time the practice was formally discontinued — driven by conservation concerns that the dragons were losing their natural hunting drive and becoming food-conditioned to human-associated settings — a generation of animals at both sites had been effectively habituated to close human proximity as a normal condition of their lives.
Cessation of the feeding programme did not immediately reset this relationship. Walpole (2001), in a landmark Animal Conservation study cited in the Ardiantiono paper, documented the cascading effects of ending supplementary feeding at Komodo National Park: dragon numbers at the former feeding sites declined toward natural levels as the artificial aggregation dispersed, but tourists were less likely to see dragons at close range, visitor satisfaction metrics fell, and local goat-vendor communities lost income. Some historical accounts suggest that the largest feeding-habituated individuals, accustomed to receiving food at particular locations, continued to return and wait even after provisioning stopped — with some dying near the former sites. The Ardiantiono study finds that the behavioural legacy of this era persists at both Loh Liang and Loh Buaya through human food refuse, proximity to kitchens and waste disposal, and the continued density of human activity, even without the formalised feeding demonstrations themselves.
Historical Context
The original goat-feeding spectacle at Loh Liang was described by Walter Auffenberg, whose 1981 field monograph The Behavioral Ecology of the Komodo Monitor remains a foundational reference. Auffenberg's observations predate the peak provisioning era and provide the natural-behaviour baseline against which the habituation documented in later studies — including Ardiantiono et al. (2018) — can be measured.
Body Condition & Demographic Consequences
One of the counterintuitive findings of Ardiantiono et al. (2018) is that Komodo dragons in high-ecotourism zones show better body condition and greater mass than conspecifics in low-tourism areas — a pattern interpreted not as a tourism benefit but as a reflection of site-selection bias, since ecotourism facilities are built in locations that already support high dragon densities due to superior habitat quality.
One of the most counterintuitive findings of the paper is that, measured against simple indices of individual fitness, dragons at high human-activity sites appear to be doing well. The study's phenotypic data show that dragons in the ecotourism zones exhibited significantly larger body mass and better body condition — expressed as the residual of log body mass on log total length — than conspecifics at low and negligible human-activity sites. Survival probability, estimated from mark-recapture data, was also higher at the high-activity sites.
The explanation is straightforward: those sites provide ongoing nutritional subsidies. The residual food sources associated with ranger stations, tourist kitchens, accommodation facilities, and food waste near the Loh Liang and Loh Buaya visitor areas supplement the prey that dragons obtain through natural hunting. An individual that can reliably supplement its diet with calorie-rich human food refuse will accrue better body reserves than one that must sustain itself entirely on wild prey under the energetic demands of active foraging. In nutritional terms, ecotourism infrastructure acts as an unintentional feeder.
However, the demographic data complicate this picture considerably. The age structure and sex ratio at high human-activity sites were both shifted relative to sites with low and negligible human presence. High-activity sites showed adult-biased age structures, with lower proportions of juveniles and subadults than would be expected under a stable, naturally recruiting population. This is consistent with the well-documented pattern in large reptiles whereby smaller individuals actively avoid areas dominated by large adults, since the risk of predation or aggressive displacement by large conspecifics is a serious threat. By concentrating large, food-supplemented adults at ecotourism sites, human activity creates conditions of elevated intraspecific competition that suppress juvenile occupancy and potentially reduce recruitment into the local population.
The sex ratio findings add a further layer of concern. Skewed adult sex ratios at high-activity sites may reflect differential habitat use by males and females, or differential survival patterns driven by intraspecific dominance dynamics among food-conditioned animals. Regardless of mechanism, a population that is simultaneously adult-biased and sex-ratio-skewed faces reduced reproductive capacity relative to its size, meaning that the apparently healthy body condition of individuals at ecotourism sites may mask a local demographic trajectory that is less stable than it appears.
Management Implications
The findings of Ardiantiono et al. (2018) carry direct and specific implications for the management of Komodo National Park, and for how ecotourism infrastructure is designed and operated at sites that house wild populations of large apex predators generally.
The authors recommend three interrelated management strategies. First, the removal of human-mediated nutritional subsidies: this means not only maintaining the cessation of the formal ranger feeding programme, but also rigorously controlling food waste and refuse disposal at all tourist facilities within the Park. Even informal subsidies — food scraps, accessible kitchen waste, improperly stored provisions — sustain the food-conditioning dynamic that drives habituation and demographic distortion at high-activity sites. Waste management infrastructure at visitor facilities needs to be treated as a conservation tool, not merely a hygiene consideration.
Second, the authors advocate for alternative ecotourism formats that reduce the concentration of human activity at a small number of fixed sites. The current configuration of Komodo National Park's tourism, in which the majority of visitors are funnelled through Loh Liang and Loh Buaya, creates the very density of human presence that drives the documented effects. Distributing visitors more broadly across the Park — to lower-activity sites where dragons exhibit natural behaviour — would improve both the conservation integrity of the high-activity sites and the quality of the wildlife encounter for visitors who seek to observe dragons acting as the wild hunters they are.
Third, the paper calls for spatial regulation of ecotourism: the formal designation of buffer zones or restricted periods around particularly sensitive areas, including nesting sites and the movement corridors through which dragons disperse away from tourist concentrations. Spatial zoning is a well-established tool in protected area management and would allow park authorities to maintain the economic benefits of tourism at designated sites while protecting the demographic integrity of the broader population.
Underpinning all three recommendations is a broader argument for what the authors call socio-ecological sustainability — an approach to park management that explicitly weighs the effects of human presence on wildlife demography alongside the economic and experiential value that tourism generates. The paper's findings make clear that these two dimensions are not simply in tension; a tourism operation that habituates large predators to close human contact and distorts their population structure is also undermining the long-term ecological integrity of the attraction on which the operation depends.
Myths vs Facts
| Common Assumption | What the Paper Found |
|---|---|
| Dragons near tourist areas are behaving naturally — they are just used to people. | Habituation is real but reflects disrupted wariness responses driven by food conditioning, not a benign familiarity. The change in behaviour is accompanied by measurable shifts in body condition and demography. |
| Stopping the formal ranger feeding programme resolved the food-subsidy problem at Loh Liang and Loh Buaya. | Informal subsidies from food waste and tourist refuse at visitor facilities continue to provide nutritional supplementation, sustaining the ecological effects of the provisioning era even without formalised feeding demonstrations. |
| Better body condition and higher survival at ecotourism sites mean those dragons are thriving. | Individual condition metrics are elevated, but these benefits are offset by adult-biased age structures, skewed sex ratios, and elevated intraspecific competition that may reduce local reproductive output. |
| The old goat-feeding spectacles were simply a historical curiosity with no lasting legacy. | The feeding era conditioned generations of animals at Loh Liang and Loh Buaya to associate human presence with food. The behavioural and demographic patterns documented in 2018 are a direct legacy of that conditioning. |
| Concentrating tourists at Loh Liang and Loh Buaya protects the rest of the Park. | Concentration creates localised demographic distortion: adult-biased, food-conditioned populations at visitor centres may not function as healthy demographic source populations for the broader park. |
| Dragons that approach tourists are simply bold individuals; it tells us nothing about population-level effects. | The reduced wariness and approach behaviour at high-activity sites is a population-wide pattern, not a trait of outlier individuals, indicating systemic rather than individual-level change. |
Key Takeaways
- Habituation is documented and site-specific. Varanus komodoensis at Loh Liang and Loh Buaya show significantly lower flight distances and higher rates of neutral or approach responses compared to dragons at low and negligible human-activity sites in the same park.
- The ranger feeding era left a measurable legacy. Decades of supplementary provisioning at the main visitor centres conditioned animals at those sites to associate human proximity with food. The formal feeding programme has ended, but informal subsidies from visitor facility waste sustain the food-conditioning dynamic.
- Better individual condition does not mean a healthy population. Dragons at ecotourism sites are heavier and survive better, but their populations are adult-biased and sex-ratio-skewed — patterns consistent with reduced juvenile recruitment driven by high intraspecific competition.
- Three management strategies are recommended: removing all human-mediated nutritional subsidies; shifting to alternative ecotourism formats that disperse visitors more widely; and implementing spatial regulation to protect sensitive demographic areas.
- Socio-ecological sustainability is the framework. The paper argues that long-term conservation of V. komodoensis in Komodo National Park requires explicit co-management of tourism's effects on wildlife demographics — not merely the maintenance of visitor numbers and revenue.
Frequently Asked Questions
What exactly were the three levels of human activity that the study compared?
The high-activity category encompassed the main tourist and ranger hubs at Loh Liang (Komodo Island) and Loh Buaya (Rinca Island), where visitor footfall, ranger presence, and associated infrastructure are concentrated throughout the tourism season. The low-activity category included peripheral areas within the park that see occasional ranger patrols and limited visitor access but lack permanent tourism facilities. The negligible-activity category covered remote sections of the park with minimal regular human presence, serving as a behavioural baseline closest to the pre-tourism condition of the population.
How did the authors measure "body condition" in wild dragons?
Body condition in the study was calculated as the residual of log-transformed body mass regressed against log-transformed total body length. A positive residual means an individual is heavier than the average for its size, indicating better fat and muscle reserves; a negative residual indicates below-average mass for length. This method is standard in herpetology and large reptile ecology because it controls for the confounding effect of size, allowing researchers to compare the nutritional state of individuals that differ substantially in total body length — as is the case across the broad size range of V. komodoensis.
Were the behavioural differences caused by individual-level learning or population-level selection?
The paper does not attempt to disentangle individual learning from selective processes within the scope of a single study — doing so would require long-term individual tracking across the life histories of marked animals. What the data demonstrate is a consistent, population-wide difference in behavioural phenotype between high- and low-activity sites. This pattern is most parsimoniously explained by repeated individual conditioning through food-associated human encounters at the high-activity sites, but the authors acknowledge that some degree of selective retention of bolder phenotypes is possible and worth investigating in future research.
Why was the ranger feeding programme considered a conservation problem if it increased dragon numbers at the sites?
Population count alone is a poor metric of conservation health. Walpole (2001), cited in the study, showed that when feeding ceased at Komodo National Park, dragon numbers at the feeding sites declined to natural levels — meaning the elevated numbers were entirely dependent on the artificial food supply, not on genuine habitat carrying capacity. The apparent population benefit was a mirage that masked food dependency, compressed home ranges, heightened intraspecific aggression, and a progressive loss of natural foraging behaviour. A food-conditioned population that no longer hunts effectively is ecologically dysfunctional regardless of its numerical size.
How do the findings of this paper relate to broader Komodo dragon conservation concerns?
This paper focuses on within-park, site-level effects at the two most heavily visited locations. It is distinct from studies of range-wide population trends, which document V. komodoensis decline on Flores Island outside the park — see Ariefiandy et al. (2021) for that analysis. The two papers are complementary: where the Ariefiandy study reveals the species is contracting at the range periphery from habitat loss and poaching, Ardiantiono et al. reveal that even within the protected core, ecotourism creates ecologically consequential distortions that require active management.
Does the study recommend reducing or stopping tourism at Komodo National Park?
No. The recommendations are specifically about restructuring how tourism is delivered, not about eliminating it. The paper acknowledges that ecotourism generates the revenues and political will that sustain the park's protective status and fund the long-term monitoring on which papers like this one depend. The argument is that the current format — concentrating visitors at Loh Liang and Loh Buaya with insufficient waste management controls — creates avoidable ecological costs. Dispersing tourism more broadly across the park, controlling food waste rigorously, and spatially zoning sensitive habitats would allow tourism to continue while reducing the demographic distortion at the main visitor sites.
Did the study find any negative effects of tourism on individual dragons beyond behaviour and body condition?
The demographic data indicate that the adult-biased age structure at high-activity sites is itself a negative effect at the population level, even though individual adults at those sites show elevated body condition and survival. A locally skewed age structure suppresses juvenile occupancy in the immediate tourist zone, potentially reducing recruitment and local population self-sustainability. The study also notes that elevated intraspecific competition at food-enriched sites may alter dominance dynamics and predation risk for smaller animals — effects that would only become fully apparent through longer-term demographic tracking than was available within the study period.
Has the management of Komodo National Park changed in response to this study?
Ardiantiono et al. (2018) is part of a cumulative evidence base — including the earlier Walpole (2001) feeding study and the long-term KSP demographic monitoring series — that has informed ongoing discussions between the Komodo Survival Program, Indonesian park authorities, and international conservation bodies about visitor management at Loh Liang and Loh Buaya. The formal feeding demonstrations had already been discontinued before this paper was published. The study's specific recommendations regarding waste management, tourism dispersal, and spatial zoning represent aspirational management targets that conservation managers at the park continue to reference in planning processes.
Sources & Further Reading
- Ardiantiono, Jessop, T.S., Purwandana, D., Ariefiandy, A., Ciofi, C., Imansyah, M.J., & Panggur, M.R. (2018). "Effects of human activities on Komodo dragons in Komodo National Park." Biodiversity and Conservation, 27(13), 3329–3347. doi.org/10.1007/s10531-018-1601-3
- Walpole, M.J. (2001). "Feeding dragons in Komodo National Park: a tourism tool with conservation complications." Animal Conservation, 4(1), 67–73. doi.org/10.1017/S136794300100107X
- Purwandana, D., Ariefiandy, A., Imansyah, M.J., Seno, A., Ciofi, C., Letnic, M., & Jessop, T.S. (2016). "Ecological allometries and niche use dynamics across Varanus komodoensis ontogeny." The Science of Nature, 103(27). doi.org/10.1007/s00114-016-1351-6
- Ariefiandy, A., Purwandana, D., Jessop, T.S., Benu, Y.J., Ciofi, C., Shepherd, C.R., & Fordham, D.A. (2021). "Lizard on the edge: multi-year surveys document severe range contraction in the world's largest lizard on Flores Island, Indonesia." Oryx, 55(4), 547–557.
- Auffenberg, W. (1981). The Behavioral Ecology of the Komodo Monitor. University Presses of Florida. The foundational field monograph providing the natural-behaviour baseline against which all subsequent human-impact studies are measured.
- Jessop, T.S., Madsen, T., Ciofi, C., Imansyah, M.J., Purwandana, D., Rudiharto, H., Arifiandy, A., & Phillips, J.A. (2007). "Island differences in population size structure and growth rates in Varanus komodoensis: effects of prey and habitat." Biological Journal of the Linnean Society, 90(2), 301–310.
- Fry, B.G., et al. (2009). "A central role for venom in predation by Varanus komodoensis (Komodo dragon) and the extinct giant Varanus (Megalania) priscus." Proceedings of the National Academy of Sciences, 106(22), 8969–8974. doi.org/10.1073/pnas.0810883106
- Jones, M.E.H., Aponte-Gutiérrez, A., Auliya, M., Ciofi, C., Clulow, S., Jessop, T.S., et al. (2020). "Climate warming, range shifts and the vulnerability of the world's largest lizard, the Komodo dragon." Ecology and Evolution, 10(22), 12041–12059.