Understanding how the spatial distribution of ecological resources shape species’ diversity and abundance in human-modified landscapes is a central theme in conservation biology. However, studies often disregard that such patterns may vary over time, thereby potentially missing critical environmental constraints to species persistence. This may be particularly important in highly mobile species such as bats, which are able to track temporal variations in spatial resource distribution. Here we test the hypothesis that bats in Mediterranean landscapes are strongly affected by the progressive reduction in water availability during the seasonal summer drought. We analysed the effects of landscape composition and structure on bat diversity and activity, during Pregnancy, Lactation and Post-lactation periods, and identified the most influential variables within and across periods. Water bodies showed the strongest positive effect on bats, followed by riparian habitats and areas with steeper (>30%) slopes. However, while during Pregnancy there were only small landscape effects, these increased during Lactation and Post-lactation, highlighting a progressively stronger association with water habitats during the summer drought. The spatial projection of habitat models showed that the landscape distribution of bat diversity and activity hotspots changed markedly over time. During Pregnancy the spatial pattern of hotspot distribution was weakly defined, while during Lactation and particularly Post-lactation there was a concentration of hotspots along permanently flowing watercourses. Our study highlights that permanently flowing watercourses are critical for bat conservation in Mediterranean landscapes, calling for measures to counteract their ongoing degradation due in particular to climate change, water abstraction and damming. More generally, our study underlines the importance of considering the temporal dimension in habitat selection studies, without which there is the risk of overlooking the importance of habitats that are key for species persistence only at certain times of the year.

In bats, sexual segregation has been described in relation to differential use of roosting and foraging habitats. It is possible that variation may also exist between genders in the use of different prey types. However, until recently this idea was difficult to test owing to poorly resolved taxonomy of dietary studies. Here, we use high-throughput sequencing to describe gender-related variation in diet composition of the European free-tailed bat (Tadarida teniotis), while controlling for effects of age and season. We analysed guano pellets collected from 143 individuals mist-netted from April to October 2012 and 2013, in northeast Portugal. Moths (Lepidoptera; mainly Noctuidae and Geometridae) were by far the most frequently recorded prey, occurring in nearly all samples and accounting for 96 out of 115 prey taxa. There were significant dietary differences between males and females, irrespective of age and season. Compared to males, females tended to consume larger moths and more moths of migratory behaviour (e.g. Autographa gamma). Our study provides the first example of gender-related dietary variation in bats, illustrating the value of novel molecular tools for revealing intraspecific variation in food resource use in bats and other insectivores.