Fig. 6.

Calling metabolism and body temperature of singing males. a Relationship of the average mass-specific CO₂ production rate of solo singing males and their chirp period (R ² = 0.65, CO₂ rate = (−25.524 × solo CP) + 78.414, N = 12 males, about 3 songs per male). b Average mass-specific volume of CO₂ produced per chirp as a function of chirp duration (R ² = 0.42, CO₂ volume = (0.2151 × chirp duration) − 15.386, N = 11 males). c Average mass-specific CO₂ production rate of 12 males entrained to three different signal periods indicated by arrows. Data in b and c are from the same experiments. Infrared thermogram of a resting (d) and singing (e) male. f Average difference in surface thorax temperature between singing and resting males in three species of the genus Mecopoda (measured by means of an infrared thermometer)