ZEMCH 2015 - International Conference Proceedings | Page 644

Figure 11: Nightjar buccal area widely opened (Besgroup2009)
Nightjars starts to increase gular vibration and increases its breathing rate to achieve evaporative
cooling that helps reducing heat caused by the high temperatures and sun exposure in order to
achieve thermal comfort. The mechanism of evaporative cooling happens when the breathing
is increased and the air passes through the moist texture of the buccal due to the wide opening of the mouth, although the rate of gular vibration is constant, the times spent fluttering and
the amount of air that passes through the buccal controls the amount of evaporative cooling
achieved (Lasiewski 1969:1 504).

Figure 12: Nightjar main features

Figure 13: Evaporative cooling technique in Nightjars (AskNature 2012)

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ZEMCH 2015 | International Conference | Bari - Lecce, Italy