Aquatic-to-terrestrial habitat shift reduces energy expenditure in newts.

Many organisms seasonally modify their standard metabolic rates (SMR). However, the diversity of cues triggering the acclimatization response remains little understood. We examined the influence of experimentally induced aquatic-to-terrestrial habitat shift on the thermal sensitivity of SMR in newts. Standard metabolic rates increased with temperature (13-23°C), although consistently lower in terrestrial than aquatic individuals. Motor activity during respirometry trials decreased with temperature at similar rates in both groups. We conclude that in newts, a habitat shift might represent an important modulator of the seasonal acclimatization response in SMR. Lowered SMR suggests the potential to reduce newt maintenance costs and depletion of caloric reserves during the activity-limited period on land.