Data from: Movement seasonality in a desert-dwelling bat revealed by miniature GPS loggers

Background: Bats are among the most successful desert mammals. Yet, our understanding of their spatio-temporal dynamics in habitat use associated with the seasonal oscillation of resources is still limited. In this study, we have employed state-of-the-art lightweight GPS loggers to track the yellow-winged bat Lavia frons in a desert in northern Kenya to investigate how seasonality in a desert affects the a) spatial and b) temporal dimensions of movements in a low-mobility bat. Methods: Bats were tracked during April–May 2017 (rainy season) and January–February 2018 (dry season) using 1-g GPS loggers. Spatial and temporal dimensions of movements were quantified, respectively, as the home range and nightly activity patterns. We tested for differences between seasons to assess responses to seasonal drought. In addition, we quantified home range overlap between neighbouring individuals to investigate whether tracking data will be in accordance with reports on territoriality and social monogamy in L. frons. Results: We obtained data for 22 bats, 13 during the rainy and 9 during the dry season. Home ranges averaged 5.46 ± 11.04 ha and bats travelled a minimum distance of 99.69 ± 123.42 m/hour. During the dry season, home ranges were larger than in the rainy season, and bats exhibited high activity during most of the night. No apparent association with free water was identified during the dry season. The observed spatial organisation of home ranges supports previous observations that L. frons partitions the space into territories throughout the year. Conclusions: Our results suggest that, in low-mobility bats, a potential way to cope with seasonally harsh conditions and resource scarcity in deserts is to cover larger areas and increase time active, suggesting lower cost-efficiency of the foraging activity. Climate change may pose additional pressures on L. frons and other low-mobility species by further reducing food abundances.研究背景：蝙蝠是最为成功的荒漠哺乳动物类群之一。然而，目前学界对其栖息地利用的时空动态与资源季节波动间关联的认知仍较为有限。本研究采用当前最先进的轻量化GPS定位记录仪（GPS logger），在肯尼亚北部的一处荒漠中对黄翼蝠（Lavia frons）进行追踪，以探究荒漠季节变化如何影响低活动能力蝙蝠的a）空间活动维度与b）时间活动维度。 研究方法：本研究于2017年4-5月（雨季）与2018年1-2月（旱季），借助重量仅1克的GPS定位记录仪对蝙蝠进行追踪。研究分别以家域范围（home range）与夜间活动模式作为量化指标，对蝙蝠活动的空间与时间维度进行分析。本研究通过检验不同季节间的差异，以评估蝙蝠对季节性干旱的响应。此外，本研究还量化了相邻个体间的家域重叠度，以验证追踪数据是否与黄翼蝠（Lavia frons）领域性与社会单配制的相关研究报道相符。 研究结果：本研究共获取22只蝙蝠的追踪数据，其中雨季13只，旱季9只。受试蝙蝠的家域范围平均为5.46±11.04公顷，每小时最小移动距离为99.69±123.42米。旱季时，蝙蝠的家域范围较雨季更大，且夜间多数时段均保持较高活动水平。旱季期间未发现蝙蝠与自由水体存在明显关联。本次观测到的家域空间分布格局，验证了此前关于黄翼蝠（Lavia frons）全年将空间划分为专属领域的研究结论。 研究结论：本研究结果表明，对于低活动能力的蝙蝠而言，应对荒漠季节性恶劣环境与资源匮乏的潜在策略之一，是扩大活动范围并增加活动时长，这意味着其觅食活动的成本效益较低。气候变化或因进一步降低食物资源丰度，给黄翼蝠（Lavia frons）及其他低活动能力物种带来额外生存压力。