Climate change poses a major challenge for many species. Whether they can cope with the associated changed conditions like increased temperatures and more frequent extreme weather events, is highly dependent on their ability to adapt.  Bats of the temperate zone evolved several behaviors that make them especially interesting to study in the context of global warming. To overcome periods of unfavorable conditions or reduced food supply, they can put themselves into torpor, a state in which they selectively lower their body temperature and thus their metabolic costs. To share energetic costs in the roost, some species engage in social thermoregulation, the cooperative maintenance of body temperature. In addition, some species regularly change roosting sites during the breeding season, partly to reduce predation pressure, but also to adapt to different weather conditions. Could such characteristics and behaviors allow bats to better cope with changing climatic conditions, and if so, to what extent?

Within the RESPONSE project A3, I investigate how climate change will affect several maternity  populations of the Bechstein’s Bat (Myotis bechsteinii) in southern Germany. During the previous cohort of the same project, it was found that increased ambient summer temperature affects growth of juveniles in this species, resulting in larger body sizes (Mundinger et al. 2021). However, so far it remained unclear if this is a direct effect of temperature on body growth or rather an indirect effect, e.g. due to increased insect availability in warmer conditions. To investigate a possible direct effect independently of other influences, we designed and conducted an experiment that allows us to directly influence roost temperatures during the growth phase of the juveniles.

To predict whether the populations of M. bechsteinii can persist in expected climatic conditions, in another project, I plan to apply Integrated Population Models (IPMs). By using this modern population modeling approach in conjunction with existing long-term field data going back more than 25 years, I expect to obtain relatively accurate estimates of demographic parameters like productivity and survival rate. These parameters then form the basis for analyses of the population viability under different climate change scenarios.

In addition to studying the effects of climate change, I am also interested in other anthropogenic impacts on biodiversity. In particular, macroecological approaches and data analyses to assess the contribution of urbanisation and the impact of invasive species have been the focus of my research to date.

Wolf J, Jeschke JM, Voigt CC, & Itescu Y (2022). Urban affinity and its associated traits: A global analysis of bats. Global Change Biology, 28: 5667–5682. https://doi.org/10.1111/gcb.16320.

Wolf J, Haase D, Kühn I (2020). The functional composition of the neophytic flora changes in response to environmental conditions along a rural-urban gradient. NeoBiota 54: 23–47. https://doi.org/10.3897/neobiota.54.38898.

Kühn I, Wolf J, Schneider A (2017). Is there an urban effect in alien plant invasions? Biological Invasions 19: 3505–3513. https://doi.org/10.1007/s10530-017-1591-1.