Seasonal Fluctuation in Thermoregulatory Behaviour of Long-Billed Vulture (Gyps indicus) by Wing Stretching at Southern Rajasthan, India

Abstract

Long-billed vulture is warm-blooded and they regulate body temperature by solar radiation. Thermoregulatory behaviour plays an important role for organism survival and its fitness. It also plays a major role in removal of ectozoons, cleaning of body and feathers, elimination of sand particles, wing flexibility and is also helpful in long distance flight. Maximum thermoregulation time recorded in winter were (680±95.65) and minimum were (516.07 ±68.66) seconds in summer in per day. Maximum thermoregulation time’s record in winter was due to low environmental temperature, high humidity and low wind velocity. In winter maximum average temperature was (27.12±2.88°C) and minimum was (8.63±3.03°C), while thermoregulation time minimum recorded in summer due to high environmental temperature. In summer season maximum average temperature was recorded (39.34± 2.10°C) and minimum was (23.08±4.49°C). Thermoregulation is influenced by various ecological parameters like- temperature, rain, sunshine period, wind velocity and cloudy weather. Thermoregulatory times reduced when environmental temperature increased. In summer long billed vulture protect nestling from direct sunlight.