Sun Basking Behaviour and Ecological Significance of Banbakri Antelope (Boselaphus tragocamelus, Pallas 1766), India

Abstract

India is home to the majestic white footed Banbakri antelope (Boselaphus tragocamelus), one of the most remarkable antelope species in the world. However, this species has not received the attention given to other charismatic fauna. Basking behaviour plays an important role in animal survival and physiological fitness. While sun basking behaviour has been observed in various mammalian species. The present study aimed to observe and analyze sun basking behaviour in free-ranging Banbakri antelopes in Bihar, India using direct sighting methods. For the sun basking behaviour study, major two Banbakri herds were monitored. During the winter season, these antelopes frequently engaged in sunbathing, likely to regulate body temperature, eliminate ectoparasites, and enhance muscle performance and immunity. The average maximum sun basking time recorded in winter was 15.01 ± 2.46 minutes, while the minimum in summer was 10.06 ± 1.86 minutes. This seasonal difference may be attributed to environmental temperatures, with winter temperatures ranging from 7.85 ± 2.09°C (minimum) to 26.38 ± 1.71°C (maximum), and summer temperatures ranging from 23.28 ± 4.31°C (minimum) to 40.18 ± 2.00°C (maximum). As temperatures increased during summer, basking time decreased or minimum in comparison to winter and antelopes were observed resting in the shade of trees to avoid direct sunlight during peak heat hours. Banbakri antelopes maximize the uptake of radiant heat by adjusting their basking positions to increase the surface area of their body exposed to the sun, while simultaneously minimizing predation risk by keeping basking periods relatively short. This study provides the first evidence of thermoregulatory basking behaviour in Boselaphus tragocamelus under free-ranging conditions in Bihar, India. Our findings highlight the adaptive significance and provide the first evidence of sunbathing in Banbakri antelope, (Boselaphus tragocamelus) highlighting its role in thermoregulation.