The effect of large body size on the temperature regulation of the komodo dragon, Varanus komodoensis

Thermal Aspects of Melanistic and Striped Morphs of the Snake Elaphe quadrivirgata

“…The heating rate during the presumed basking stage was negatively correlated with body size in both morphs. This result corresponds with those of previous empirical and theoretical studies (e.g., McNab and Auffenberg, 1976;Stevenson, 1985;Turner and Tracy, 1985;Seebacher et al, 1999). An interesting trend in relation to heating rate and body size shown by the present study is that the slope of the regression equation for heating rate against BM is steeper in the melanistic morph than in the striped morph, although the difference is not statistically significant.…”

Thermal Aspects of Melanistic and Striped Morphs of the Snake Elaphe quadrivirgata

“…The heating rate during the presumed basking stage was negatively correlated with body size in both morphs. This result corresponds with those of previous empirical and theoretical studies (e.g., McNab and Auffenberg, 1976;Stevenson, 1985;Turner and Tracy, 1985;Seebacher et al, 1999). An interesting trend in relation to heating rate and body size shown by the present study is that the slope of the regression equation for heating rate against BM is steeper in the melanistic morph than in the striped morph, although the difference is not statistically significant.…”

Body temperature and thermoregulation of Komodo dragons in the field

“…As pointed our by Bakken (1976), the cooling constant is best determined using T e of animals in a laboratory setting with a stable end temperature (Bartholomew and Lasiewski, 1965). In spite of this, our calculations using T a of free ranging dragons resulted in the allometric relationship: a ¼ À1.23 M À 0.766 which, unlike the results of McNab and Auffenberg (1976), is very close to the value reported by Bartholomew and Tucker (1964) for varanids.…”

“…heart rate hysteresis) with enhanced peripheral vasodilation during heating compared to vasoconstriction during cooling as described in other varanid lizards (Grigg et al, 1979;Seebacher and Grigg, 2001;Seebacher and Shine, 2004). Interestingly, McNab and Auffenberg (1976) calculated cooling constants on four dragons ranging from 7-35 kg and found these values to be well below that predicted by allometric equations of varanids (Bartholomew and Tucker, 1964). However, this may be a result of these animals being tethered overnight in the open sky and therefore do not represent naturally occurring conditions.…”

“…Many previous studies have attempted to identify the range of preferred temperatures for different size groups of Komodo dragons in the field. McNab and Auffenberg (1976) report the T b of four active dragons (7-35 kg) by telemetry to be in the range 35-40 1C. However the variability in these data was quite large and no association was made to mass specific T b .…”

How far did dinosaurs really migrate, and how hot do elephants really get?

“…Gregory Paul is correct in pointing out the evidence that high latitude populations may have been permanent polar residents (Bell and Snively, 2008;. However, it is likely that large ectothermic dinosaurs would succumb to a lethal level of hypothermia during exposure to several months of cold and dark polar winters (McNab and Auffenberg, 1976;Spotila et al, 1973). Therefore, while our model did not prove endothermic metabolism in hadrosaurs, permanent residency at high latitudes strengthens our argument for endothermic metabolism in polar hadrosaurs.…”

Thermal Aspects of Melanistic and Striped Morphs of the Snake Elaphe quadrivirgata

“…The heating rate during the presumed basking stage was negatively correlated with body size in both morphs. This result corresponds with those of previous empirical and theoretical studies (e.g., McNab and Auffenberg, 1976;Stevenson, 1985;Turner and Tracy, 1985;Seebacher et al, 1999). An interesting trend in relation to heating rate and body size shown by the present study is that the slope of the regression equation for heating rate against BM is steeper in the melanistic morph than in the striped morph, although the difference is not statistically significant.…”

Body temperature and thermoregulation of Komodo dragons in the field

“…As pointed our by Bakken (1976), the cooling constant is best determined using T e of animals in a laboratory setting with a stable end temperature (Bartholomew and Lasiewski, 1965). In spite of this, our calculations using T a of free ranging dragons resulted in the allometric relationship: a ¼ À1.23 M À 0.766 which, unlike the results of McNab and Auffenberg (1976), is very close to the value reported by Bartholomew and Tucker (1964) for varanids.…”

“…heart rate hysteresis) with enhanced peripheral vasodilation during heating compared to vasoconstriction during cooling as described in other varanid lizards (Grigg et al, 1979;Seebacher and Grigg, 2001;Seebacher and Shine, 2004). Interestingly, McNab and Auffenberg (1976) calculated cooling constants on four dragons ranging from 7-35 kg and found these values to be well below that predicted by allometric equations of varanids (Bartholomew and Tucker, 1964). However, this may be a result of these animals being tethered overnight in the open sky and therefore do not represent naturally occurring conditions.…”

“…Many previous studies have attempted to identify the range of preferred temperatures for different size groups of Komodo dragons in the field. McNab and Auffenberg (1976) report the T b of four active dragons (7-35 kg) by telemetry to be in the range 35-40 1C. However the variability in these data was quite large and no association was made to mass specific T b .…”

How far did dinosaurs really migrate, and how hot do elephants really get?

“…Gregory Paul is correct in pointing out the evidence that high latitude populations may have been permanent polar residents (Bell and Snively, 2008;. However, it is likely that large ectothermic dinosaurs would succumb to a lethal level of hypothermia during exposure to several months of cold and dark polar winters (McNab and Auffenberg, 1976;Spotila et al, 1973). Therefore, while our model did not prove endothermic metabolism in hadrosaurs, permanent residency at high latitudes strengthens our argument for endothermic metabolism in polar hadrosaurs.…”

Thermal Aspects of Melanistic and Striped Morphs of the Snake Elaphe quadrivirgata

“…The heating rate during the presumed basking stage was negatively correlated with body size in both morphs. This result corresponds with those of previous empirical and theoretical studies (e.g., McNab and Auffenberg, 1976;Stevenson, 1985;Turner and Tracy, 1985;Seebacher et al, 1999). An interesting trend in relation to heating rate and body size shown by the present study is that the slope of the regression equation for heating rate against BM is steeper in the melanistic morph than in the striped morph, although the difference is not statistically significant.…”

Body temperature and thermoregulation of Komodo dragons in the field

“…As pointed our by Bakken (1976), the cooling constant is best determined using T e of animals in a laboratory setting with a stable end temperature (Bartholomew and Lasiewski, 1965). In spite of this, our calculations using T a of free ranging dragons resulted in the allometric relationship: a ¼ À1.23 M À 0.766 which, unlike the results of McNab and Auffenberg (1976), is very close to the value reported by Bartholomew and Tucker (1964) for varanids.…”

“…heart rate hysteresis) with enhanced peripheral vasodilation during heating compared to vasoconstriction during cooling as described in other varanid lizards (Grigg et al, 1979;Seebacher and Grigg, 2001;Seebacher and Shine, 2004). Interestingly, McNab and Auffenberg (1976) calculated cooling constants on four dragons ranging from 7-35 kg and found these values to be well below that predicted by allometric equations of varanids (Bartholomew and Tucker, 1964). However, this may be a result of these animals being tethered overnight in the open sky and therefore do not represent naturally occurring conditions.…”

“…Many previous studies have attempted to identify the range of preferred temperatures for different size groups of Komodo dragons in the field. McNab and Auffenberg (1976) report the T b of four active dragons (7-35 kg) by telemetry to be in the range 35-40 1C. However the variability in these data was quite large and no association was made to mass specific T b .…”

How far did dinosaurs really migrate, and how hot do elephants really get?

“…Gregory Paul is correct in pointing out the evidence that high latitude populations may have been permanent polar residents (Bell and Snively, 2008;. However, it is likely that large ectothermic dinosaurs would succumb to a lethal level of hypothermia during exposure to several months of cold and dark polar winters (McNab and Auffenberg, 1976;Spotila et al, 1973). Therefore, while our model did not prove endothermic metabolism in hadrosaurs, permanent residency at high latitudes strengthens our argument for endothermic metabolism in polar hadrosaurs.…”