Heterotherms vary their use of torpor and choice of refugia to deal with energetic stresses such as reproductive activity and extreme weather. We hypothesized that a temperate-region bat would vary its use of heterothermy in response to air temperature but use of torpor would also be influenced by reproductive stage and roost choice. To test this hypothesis, we collected data on skin temperatures of female Indiana bats (Myotis sodalis) carrying temperature-sensitive radiotransmitters during the summers of 2013–2015. We also measured internal temperatures and external characteristics of roosts used by these bats. We analyzed the influence of daytime air temperature, roost canopy closure, roost type, and bat reproductive stage, on daily heterothermy index and torpor characteristics of 17 bats during 103 full roost days (data collected consistently from when a bat entered its roost in the morning to when it emerged at night). Our data showed that Indiana bat heterothermy was influenced by reproductive stage, roost choice, and weather. Although they used torpor, pregnant bats were the least heterothermic (daily heterothermy index = 3.3 ± 0.6°C SE), followed by juvenile bats (5.6 ± 0.5°C), lactating bats (5.7 ± 0.5°C), and one postlactating bat (13.2 ± 1.6°C). Air temperature also influenced heterothermy of pregnant bats less than bats of other reproductive stages. Thermoregulatory strategies varied on a continuum from use of normothermia in warm roosts to use of long and deep bouts of torpor in cool roosts. The thermoregulatory strategy used seemed to be determined by potential reproductive costs of torpor and energetic consequences of weather. Because Indiana bats used different degrees of heterothermy throughout the summer maternity season, managers should offer maternity colonies an array of refugia to facilitate varying behaviors in response to weather and energetic demands.

中文翻译：

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自由放养的蝙蝠会根据繁殖阶段、栖息地类型和天气改变体温调节行为

Heterotherms 改变了他们对麻木的使用和避难所的选择来应对精力充沛的压力，例如生殖活动和极端天气。我们假设温带地区的蝙蝠会根据气温而改变其对异温的使用，但对 torpor 的使用也会受到生殖阶段和栖息地选择的影响。为了验证这一假设，我们收集了 2013-2015 年夏季携带温度敏感无线电发射器的雌性印第安纳蝙蝠 (Myotis sodalis) 的皮肤温度数据。我们还测量了这些蝙蝠使用的栖息地的内部温度和外部特征。我们分析了白天气温、栖息冠层关闭、栖息类型和蝙蝠繁殖阶段的影响，103 个完整栖息日期间 17 只蝙蝠的每日异温指数和蛰伏特性（从蝙蝠早上进入栖息地到晚上出现的数据始终如一地收集）。我们的数据表明，印第安纳蝙蝠的异温性受生殖阶段、栖息地选择和天气的影响。虽然他们使用了 torpor，但怀孕的蝙蝠的异温性最低（每日异温指数 = 3.3 ± 0.6°C SE），其次是幼年蝙蝠（5.6 ± 0.5°C）、哺乳期蝙蝠（5.7 ± 0.5°C）和一只哺乳后蝙蝠(13.2 ± 1.6°C)。与其他生殖阶段的蝙蝠相比，气温对怀孕蝙蝠的异温影响也较小。从在温暖的栖息地使用常温到在凉爽的栖息地使用长而深的麻木，体温调节策略不断变化。所使用的体温调节策略似乎是由麻木的潜在繁殖成本和天气的能量后果决定的。由于印第安纳蝙蝠在整个夏季产假期间使用不同程度的异温，管理人员应为产科栖息地提供一系列避难所，以促进适应天气和能量需求的不同行为。