Data from: Resource availability and roosting ecology shape reproductive phenology of rainforest insectivorous bats

Bats in temperate and subtropical regions typically synchronize birth of a single young with peaks in resource availability driven by local climate patterns. In tropical rainforests, insects are available throughout the year, which might allow departures from seasonal monoestry, although reproductive energy budgets may be constrained by the cost of commuting to foraging grounds from distant roosts. To test these hypotheses, we simultaneously tracked female reproductive activity of 11 insectivorous bat species, insect biomass, and local weather variables for 20 months in a Malaysian rainforest. Five species roost in forest structures and hence have low commuting costs, and six species depend on caves, which are limited in the landscape, and are presumed to incur higher commuting costs to the forest foraging ground. Monthly insect biomass was positively correlated with monthly rainfall, and there was a significant relationship between insect biomass and lactation in cave-roosting, but not forest-roosting species. Cave-roosting species were seasonally monoestrus, with parturition confined to a two-month period, whereas in forest-roosting species, pregnancy and lactation were recorded throughout the year. Our results suggest that the energetic costs of commuting from roosts to foraging grounds shape annual reproductive patterns in tropical rainforest insectivorous bats. Ongoing changes in forest landscapes are likely to increase these costs for cave-roosting bats, further restricting reproductive opportunities. Climate change is projected to influence the timing of rainfall events in many tropical habitats, and this may disrupt relationships between rainfall, insect biomass and bat reproductive timing, further compromising reproductive success.温带与亚热带地区的蝙蝠通常会将单幼崽的出生时间，与当地气候模式驱动的资源可获得性峰值同步。热带雨林中，昆虫资源全年均可获取，这或许会打破季节性单动情周期（seasonal monoestry），但繁殖能量预算可能会受到从偏远栖息地前往觅食地的通勤成本限制。为验证上述假说，我们在马来西亚的一片热带雨林中，对11种食虫蝙蝠的雌性繁殖活动、昆虫生物量以及当地气象变量进行了为期20个月的同步追踪监测。其中5个物种栖息于林木结构中，因此通勤成本较低；另有6个物种依赖洞穴栖息——这类栖息点在景观中分布有限，据推测它们前往森林觅食地的通勤成本更高。月度昆虫生物量与月度降雨量呈正相关；洞穴栖息的蝙蝠物种中，昆虫生物量与泌乳期存在显著关联，但林木栖息的物种则无此关联。洞穴栖息的物种为季节性单动情周期，产仔期集中在两个月内；而林木栖息的物种全年均可观测到妊娠与泌乳现象。研究结果表明，从栖息地前往觅食地的通勤能量成本，塑造了热带雨林食虫蝙蝠的年度繁殖模式。当前森林景观的持续变化可能会提升洞穴栖息蝙蝠的此类通勤成本，进一步限制其繁殖机会。据预测，气候变化将影响诸多热带生境的降雨时序，这可能会打破降雨、昆虫生物量与蝙蝠繁殖时序之间的关联，进一步损害其繁殖成功率。