Economic thermoregulatory response explains mismatch between thermal physiology and behaviour in newts.
Temperature is an important factor determining distribution and abundance of organisms. Predicting the impact of warming climate on ectotherm populations requires information about species' thermal requirements, i.e. their so-called 'thermal niche'. The characterization of thermal niche remains a complicated task. We compared the applicability of two indirect approaches, based on reaction norm (aerobic scope curve) and optimality (preferred body temperature) concepts, for indirect estimation of thermal niche while using newts, Ichthyosaura alpestris, as a study system. If the two approaches are linked, then digesting newts should keep their body temperatures close to values maximizing aerobic scope for digestion. After feeding, newts maintained their body temperatures within a narrower range than did hungry individuals. The range of preferred body temperatures was well below the temperature maximizing aerobic scope for digestion. Optimal temperatures for factorial aerobic scope fell within the preferred body temperature range of digesting individuals. We conclude that digesting newts prefer body temperatures that are optimal for the maximum aerobic performance but relative to the maintenance costs. What might be termed the 'economic' thermoregulatory response explains the mismatch between thermal physiology and behaviour in this system.
['Gvoždík|Lumír|L|', 'Kristín|Peter|P|']
D000064:Acclimatization D000824:Animal Nutritional Physiological Phenomena D000818:Animals D001831:Body Temperature D001833:Body Temperature Regulation D004063:Digestion D004734:Energy Metabolism D005260:Female D057232:Global Warming D008297:Male D012455:Salamandridae D013696:Temperature
Thermal niche Aerobic scope Amphibians Preferred temperature Specific dynamic action Thermoregulatory behaviour