Diurnality in rodents is relatively rare and occurs primarily in areas with low nighttime temperatures such as at high altitudes and desert areas. However, many factors can influence temporal activity rhythms of animals, both in the field and the laboratory. The temporal activity patterns of the diurnal ice rat were investigated in the laboratory with, and without, access to running wheels, and in constant conditions with running wheels. Ice rats appeared to be fundamentally diurnal but used their running wheels during the night. In constant conditions, general activity remained predominantly diurnal while wheel running was either nocturnal or diurnal. In some animals, entrainment of the wheel running rhythm was evident, as demonstrated by free-running periods that were different from 24 h. In other animals, the wheel running activity abruptly switched from nocturnal to subjective day as soon as the animals entered DD, and reverted back to nocturnal once returned to LD, suggesting the rhythms were masked by light. Wheel running rhythms appears to be less robust and more affected by light compared to general activity rhythms. In view of present and future environmental changes, the existence of more unstable activity rhythms that can readily switch between temporal niches might be crucial for the survival of the species.

啮齿动物的昼夜变化相对较少，主要发生在夜间温度较低的地区，例如高海拔地区和沙漠地区。但是，无论在野外还是在实验室中，许多因素都会影响动物的时间活动节奏。在有或没有进入工作轮的情况下，以及在恒定条件下使用工作轮的情况下，在实验室中研究了昼间冰鼠的暂时活动模式。冰鼠看起来基本上是昼夜的，但在夜间却使用了它们的跑轮。在恒定条件下，一般活动主要是昼夜活动，而轮转运动是夜间活动或昼夜活动。在某些动物中，轮转的节奏很明显，这与24小时的自由行驶时间不同。在其他动物中 一旦动物进入DD，转轮的活动突然从夜间转为主观，一旦返回LD，转轮又恢复为夜间，表明节律被光线掩盖了。与一般活动节奏相比，轮转节奏似乎不那么健壮，并且受光线影响更大。鉴于当前和未来的环境变化，存在更不稳定的活动节奏，这些节奏可以在时空利基之间轻松切换可能对物种的生存至关重要。