Djungarian hamsters ( Phodopus sungorus ), originating from Asian steppes, change fur color from brown in summer to white in winter when they reduce body mass and size of reproductive organs. The species also enters energy-conserving daily torpor, characterized by a substantial temporal reduction of metabolic rate (MR) and body temperature (T b ). However, spontaneous daily torpor (food ad libitum) is only used by winter-accli...

Torpor, a controlled reduction in metabolism and body temperature, reduces energy expenditure substantially. However, torpor expression in wild passerines is currently understudied. We show that skin temperature (T s ) of resting White-throated Treecreepers ( N = 4) fell by ~ 5 °C on average in both summer and winter, independent of ambient temperature, but we could not confirm torpor use (T s reduction > 5 °C). It is possible...