In artificial roost comparison, bats show preference for rocket box style

Understanding microhabitat preferences of animals is critical for effective conservation, especially for temperate-zone bats, which receive fitness benefits from selecting optimal roost microhabitats. Artificial roost structures are increasingly being used in conservation efforts for at-risk bat species. To evaluate microhabitat differences in common artificial roost structures and determine if roost selection occurs based on structure type, we installed artificial roosts of three different styles (bat box, rocket box, and bark mimic) in six clusters. We compared size and measured temperature parameters (12 points/roost) while bats were excluded from one cluster. We simultaneously conducted census counts during the active season at five more clusters open to bats for 1–2 years. The rocket box style provided larger entrance area, surface area, and volume versus other roost types. Microclimate varied with roost design. More positions inside the bat box and rocket box stayed within critical temperature limits for bats (0–45°C)—i.e., were usable. The bark-mimic provided less usable space than the rocket box and, often, large proportions of the roost were > 45°C. The rocket box provided the widest temperature availability in a given hour (max range available 7°C) and was more stable than the bark mimic. A maternity colony of Indiana bats (Myotis sodalis) selected the rocket box style; four of five available rocket boxes became primary maternity roosts, with 2–210 bats emerging per night. Future work should aim to manipulate roost size, temperature availability, and temperature stability in isolation to identify which features drive roost microhabitat selection by bats. Comparative studies of artificial roosts account for some inherent irregularity in natural systems, allowing us to study the dynamics of roost microhabitats. We recommend season-long monitoring of microhabitat in novel artificial refuges and comparative studies of artificial and natural roosts, and urge managers to consider potential positive and negative effects when substituting artificial roosts for natural habitat.

探究动物的微生境偏好，对于开展有效的物种保护工作至关重要，尤其对于温带蝙蝠而言——这类动物通过选择最优的栖息微生境，可提升自身的适合度收益。针对受威胁蝙蝠物种的保护工作中，人工栖息结构的应用正日益广泛。为评估常见人工栖息结构的微生境差异，并探明蝙蝠是否会依据栖息结构类型选择栖息场所，我们在六个安装集群中布设了三种不同样式的人工栖息结构：蝙蝠箱（bat box）、火箭式蝙蝠箱（rocket box）与仿树皮栖息结构（bark mimic）。我们在一个蝙蝠被排除在外的集群中，对各栖息结构的尺寸进行了对比，并测量了温度参数（每个栖息结构布设12个测温点）。与此同时，在另外五个已向蝙蝠开放1至2年的安装集群的蝙蝠活动季中，我们开展了种群普查计数。相较于其他两类栖息结构，火箭式蝙蝠箱拥有更大的入口面积、表面积与容积。栖息微气候随结构设计的不同而存在差异。蝙蝠箱与火箭式蝙蝠箱内部，有更多点位的温度处于蝙蝠生存的临界温度区间（0至45℃），即具备可栖息性。仿树皮栖息结构的可栖息空间小于火箭式蝙蝠箱，且其内部常有大面积区域的温度超过45℃。火箭式蝙蝠箱在任意时刻的可利用温度区间最宽（最大区间跨度达7℃），且其温度稳定性优于仿树皮栖息结构。印第安纳蝙蝠（Myotis sodalis）的育幼种群选择了火箭式蝙蝠箱：在可供使用的5个火箭式蝙蝠箱中，有4个成为了主要育幼栖息场所，每晚有2至210只蝙蝠飞出栖息箱。未来的研究应尝试单独调控栖息结构的尺寸、可利用温度范围与温度稳定性，以明确究竟是哪些特征驱动蝙蝠对栖息微生境的选择。人工栖息结构的对照研究可抵消自然系统中部分固有的不规则性，使我们能够探究栖息微生境的动态变化规律。我们建议对新型人工栖息庇护所开展全季微生境监测，并开展人工与天然栖息结构的对照研究；同时呼吁管理者在以人工栖息结构替代自然栖息生境时，充分考量其潜在的正面与负面影响。