Abstract Context. For migratory animals, particularly those with long generation times, changing weather patterns may cause a mismatch between periods of expected and actual resource availability, termed phenological mismatch. The cave-dwelling Natal long-fingered bat (Miniopterus natalensis) is a regional migrant within South Africa for which the (hitherto unknown) phenology of migration may be affected by climate. Aims. To investigate the migration phenology of the Natal long-fingered bat in relation to climate at a maternity cave in South Africa. Methods. Five years (2014–18) of echolocation data from a maternity cave site in Limpopo, South Africa, were studied. Separate stepwise General Linear Models (GLMs) were constructed for each season using photoperiod, minimum temperature, dew point, rainfall, barometric pressure, humidity and maximum wind speed. Arrival and departure dates among years were also compared. Key results. Photoperiod had the greatest effect on the magnitude of Natal long-fingered bat phenological patterns in activity across all seasons. Although spring (September - November) arrival at the maternity site was variable across years, summer departure dates did not differ, resulting in a shorter breeding period in the 2017–18 sample year. During the 2016–17 sample year, the magnitude of Natal long-fingered bat activity was significantly lower than in other years, which coincided with El Niño-induced drought conditions and likely impacted resources and led to a reduction in activity and population size. Conclusions. Photoperiod is a strong predictive cue of the phenology of migration of the Natal long-fingered bat and likely cues migration for this species. The narrow departure dates of these bats from the maternity site supports these results. Implications. The present study indicates that Natal long-fingered bats use photoperiod as a migration cue and do not appear to shift their spring–summer breeding season, likely making them vulnerable to phenological mismatch and population decline. The research highlights the need for systematic population monitoring for the Natal long-fingered bat.

中文翻译：

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南非东北部迁徙纳塔尔长指蝙蝠（Miniopterus natalensis）物候的气候相关性

摘要上下文。对于迁徙动物，尤其是那些世代时间长的迁徙动物，不断变化的天气模式可能导致预期和实际资源可用性时期之间的不匹配，称为物候失配。居住在洞穴的纳塔尔长指蝙蝠（Miniopterus natalensis）是南非境内的一种区域性迁徙动物，其迁徙物候（迄今未知）可能受气候影响。目标。调查与南非产妇洞穴气候相关的纳塔尔长指蝙蝠的迁徙物候。方法。研究了来自南非林波波省一个产妇洞穴遗址的五年（2014-18 年）回声定位数据。使用光周期、最低温度、露点、降雨量、气压、湿度和最大风速。还比较了不同年份的到达和离开日期。关键结果。光周期对所有季节活动中纳塔尔长指蝙蝠物候模式的大小影响最大。尽管春季（9 月至 11 月）到达产房地点因年份而异，但夏季出发日期没有差异，导致 2017-18 样本年的繁殖期较短。在 2016-17 样本年，纳塔尔长指蝙蝠活动的幅度显着低于其他年份，这与厄尔尼诺现象引起的干旱条件相吻合，并可能影响资源并导致活动和种群规模减少。结论。光周期是纳塔尔长指蝙蝠迁徙物候的有力预测线索，并且可能暗示该物种的迁徙。这些蝙蝠离开产房地点的时间很短，支持这些结果。影响。目前的研究表明，纳塔尔长指蝙蝠使用光周期作为迁徙线索，并且似乎不会改变它们的春夏繁殖季节，这可能使它们容易受到物候错配和种群数量下降的影响。该研究强调了对纳塔尔长指蝙蝠进行系统种群监测的必要性。可能使它们容易受到物候错配和人口下降的影响。该研究强调了对纳塔尔长指蝙蝠进行系统种群监测的必要性。可能使它们容易受到物候错配和人口下降的影响。该研究强调了对纳塔尔长指蝙蝠进行系统种群监测的必要性。