Interesting movement and activity patterns of Asiatic lions in India

The Asiatic lions are spread across ~30000 km2 in the Saurashtra region of the Gujarat state in India, collectively known as the Asiatic Lion Landscape. The landscape includes five protected areas (Gir National Park, Gir Wildlife Sanctuary, Paniya Wildlife Sanctuary, Mitiyala Wildlife Sanctuary, and Girnar Wildlife Sanctuary) and other natural forest patches. Thanks to the effective conservation measures in the past decades with the support of local people, the Asiatic lion population has shown a good increase in the past two decades. The population has reached the mark of 674 as per the last estimation (June 2020). With the population increase, the Asiatic lions also started occupying diverse habitats outside the protected forest areas. Their dispersal outside the protected areas has led to conservation and management challenges. It is important to understand the ecology of Asiatic lions to address these challenges, especially their movements and activity. Furthermore, their movement ecology has enormous potential to inform management and policy decisions with effective conservation outcomes.

To understand the aspects mentioned above, a scientific study through radio-telemetry was envisaged on Asiatic lions with the objectives to know whether their movement and activity vary with demographic parameters such as age, sex and group size and also whether the daily distances moved and the home-ranges of individuals vary within and outside the protected areas. Therefore, radio-collars that were featured with three-axis accelerometer-based activity sensors, mortality sensors, a programmable drop-off activation system, and a programmable GPS schedule which recorded the location fixes were deployed on 19 Asiatic lions. The information was stored on-board and retrieved upon removal/replacement of the radio-collar.

The study revealed interesting variations in daily distances covered (movement) and daily activity patterns from acceleration sensors (activity) in relation to season, group size, age and sex. It found a significant difference in the mean daily distances between males and females but not between adult and sub-adult males. Females showed significantly less activity and movement compared to adult males. Adult males were significantly more active than sub-adult males.

The study also noted that the mean daily movement for adult males and females ranging outside protected areas was not different from those within the protected areas, but in the case of sub-adult males, the difference was more significant: their home ranges were larger outside the protected areas compared to those within the protected areas. The difference in space-use outside the protected areas was an artefact of long-distance forays by adult and sub-adult males and females on certain days. The foraying distances showed a characteristic pattern for sub-adult males, adult males and females. Moreover, it is well established that path selection, risk aversion and use of multi-use landscapes outside protected areas are age-sex specific. Therefore, the knowledge output from this study regarding the spatial and temporal nature of Asiatic lion movements outside protected areas will be helpful in risk assessment, planning infrastructure projects and designing conservation action plans.