Given the marked variation in abiotic and biotic conditions between day and night, many species specialise their physical activity to being diurnal or nocturnal, and it was long thought that these strategies were commonly fairly fixed and invariant. The term ‘cathemeral’, was coined in 1987, when Tattersall noted activity in a Madagascan primate during the hours of both daylight and darkness. Initially thought to be rare, cathemerality is now known to be a quite widespread form of time partitioning amongst arthropods, fish, birds, and mammals. Herein we provide a synthesis of present understanding of cathemeral behaviour, arguing that it should routinely be included alongside diurnal and nocturnal strategies in schemes that distinguish and categorise species across taxa according to temporal niche. This synthesis is particularly timely because (i) the study of animal activity patterns is being revolutionised by new and improved technologies; (ii) it is becoming apparent that cathemerality covers a diverse range of obligate to facultative forms, each with their own common sets of functional traits, geographic ranges and evolutionary history; (iii) daytime and nighttime activity likely plays an important but currently neglected role in temporal niche partitioning and ecosystem functioning; and (iv) cathemerality may have an important role in the ability of species to adapt to human-mediated pressures.

中文翻译：

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Cathemerality：关键的时间利基

鉴于白天和夜晚之间非生物和生物条件的显着变化，许多物种将其身体活动专门化为白天或夜间，并且长期以来人们认为这些策略通常是相当固定和不变的。“cathemeral”一词是在 1987 年创造的，当时塔特萨尔注意到马达加斯加灵长类动物在白天和黑夜的活动。最初人们认为这种时间划分很少见，但现在人们知道它是节肢动物、鱼类、鸟类和哺乳动物中一种相当普遍的时间划分形式。在此，我们提供了对目前对昼夜行为的理解的综合，认为它应该通常与昼间和夜间策略一起纳入根据时间生态位区分和分类跨类群物种的计划中。这种综合特别及时，因为（i）新的和改进的技术正在彻底改变动物活动模式的研究；( ii )越来越明显的是，多态性涵盖了多种从必然到兼性的形式，每种形式都有自己共同的功能特征、地理范围和进化历史；( iii )白天和夜间活动可能在时间生态位划分和生态系统功能中发挥着重要但目前被忽视的作用；( iv ) 多样性可能在物种适应人类压力的能力中发挥重要作用。