In October 2022, authorities in Bihar shot dead a three-year-old tiger named T-104, better known as the man-eater of Champaran. The tiger was responsible for the deaths of more than 9 people, and despite relocation and rehabilitation attempts, the tiger continued to hunt humans, leading to its ill fate. The majestic tiger faces a growing number of challenges in our rapidly developing nation, primarily due to its coexistence with a rapidly expanding human population. News headlines frequently highlight human-wildlife conflicts, with incidents of tigers preying on livestock or, tragically, attacking people, often leading to retaliatory killing. This escalating tension underscores a critical need to understand how these magnificent big cats navigate a world increasingly shaped by human activity.
A recent study from the University of Maryland, USA, Cardiff University, UK, Swansea University, UK, Sweden and the Wildlife Institute of India, Dehradun, offers unprecedented insights into the secret lives of subadult tigers in the Eastern Vidarbha Landscape of Maharashtra. The study reveals their remarkable ability to adapt their movements across different life stages in these complex, human-dominated environments.
Did You Know? Unlike many other cats, tigers love water and are excellent swimmers. They even use water to cool down in hot climates and can swim long distances. |
The researchers collected GPS telemetry data from 15 subadult tigers between 2016 and 2022. Each tiger wore a GPS collar that recorded its location at intervals ranging from 1 to 5 hours. This raw data was then processed to create consistent 2-hour time steps, which is crucial for the statistical models used in the next steps.
The team then employed Hidden Markov Models (HMMs), which use probabilities to infer hidden behaviours from the observed movement data. This allowed the researchers not only to classify the tigers' behaviours but also to see how external factors, such as temperature, time of day, habitat type, and even human population density, influenced the animals’ behaviour.
The researchers discovered that tigers are incredibly flexible in their behaviour, exhibiting three distinct movement patterns. Resting, which is stationary with very short steps; area-restricted movement, characterised by winding, tortuous paths with short to intermediate steps, often associated with foraging or local exploration; and travelling, involving straightforward movements over long distances. Interestingly, these behaviours change depending on the tiger's age and the surrounding environment.
Young, pre-dispersal tigers, still exploring their natal range, spent most of their time in area-restricted movement (42.10%), followed by travelling (30.47%), and resting (27.42%). They were most active, or travelling, at dusk and throughout the night, moving faster in areas with high human density, a clear sign of avoiding human encounters. Area-restricted movement was more common during the day, while resting peaked late at night.
As tigers entered the dispersal phase, a critical and often dangerous journey to find their own territory, their activity budget became surprisingly balanced across all three states, with resting (32.09%), area-restricted movement (35.77%), and travelling (32.14%) levels evened out. These dispersing tigers moved faster and more directly in areas with less cover and in non-forest habitats. They showed a greater tendency to travel at dusk and throughout the night. This nocturnal, directed movement likely helps them navigate unfamiliar, fragmented landscapes, including agricultural fields and human settlements, while minimising the risk of conflict.
Finally, post-dispersal tigers, those who had successfully established their own stable home ranges, showed increased behavioural stability. They engaged in longer step lengths during area-restricted movement in forest habitats and maintained faster travel speeds in human-agricultural areas. Interestingly, they tended to rest when temperatures were high and travelled more when it was between 20 and 30 °C.
Across all life stages, the study consistently found that tigers adjusted their movements in response to the time of day, temperature, habitat type (forest vs. non-forest), and human population density. For instance, non-forest areas, especially those with high human density, prompted faster, more directional movements, reflecting a strategy to avoid perceived threats.
This research offers a rare, life-stage-specific look at tiger movement, providing a temporal perspective on how their behaviour changes from dependence to dispersal and territory establishment. It's also one of the few studies to compare tiger movements both within and outside protected areas, shedding light on their adaptations to varying levels of human disturbance. However, the study acknowledges the small, male-biased sample used for the dispersal analysis. This means the findings lean towards male-specific movement strategies. Future research with more balanced sampling is needed to understand sex-specific variations.
By understanding how tigers adapt their movements in human-dominated landscapes, we can develop more effective strategies to ensure their long-term survival and coexistence with humans. This includes maintaining and creating functional wildlife corridors, reducing conflicts, and guiding development away from critical tiger habitats. As climate change intensifies, bringing more environmental variability and unpredictable resources, the behavioural flexibility observed in these tigers will become even more crucial for their survival.
This article was written with the help of generative AI and edited by an editor at Research Matters.