We study the complex social structure of bat groups. Some species form highly dynamic fission-fusion societies, its members being spread over a large geographical area, while continously maintaining social contacts. We are interested how these bats organize and maintain their extraordinary social organization. Hereby we apply classic telemetry, individual marking, but also use data on genetic diversity and individual relatedness.
Aerial sound recording with helium balloon
Bats are an extremely diverse group of mammals. A surprisingly high percentage of bat diversity is cryptic and can only be revealed by genetic approaches. We use mitochondrial and nuclear DNA markers to assess cryptic diversity in bat communities and to predict how historic changes in climate and geology have driven bat speciation and genetic divergence.
Isabelline serotine bat (Eptesicus isabellinus)
Stable Isotope Ecology
Stable isotope analysis is a valuable tool for ecologists to study trophic interactions, diet change and movement, particularly long-distance migration. However, it is still not fully understood how different factors, e.g. diet, physiology and environmental variation, interact to affect isotopic values in animals. Our research deals with these questions and also with the application of stable isotope analysis in the study of bat diets and migration.
Doñana National Park
Feeding strategies of bats have evolved to maximize the ratio between energy obtained from food and energy lost in daily activities such as flight and prey manipulation. We investigate bat feeding strategies by characterizing prey composition, mainly through molecular analysis in feces, defining trophic position through stable isotope analysis, and finding out where bats forage in space and time. One focus of our research is the enigmatic predator-prey interaction between the giant noctule bat and nocturnally migrating songbirds.
Greater Noctule Bat (Nyctalus lasiopterus)
Bats are highly mobile animals, but flight involves high energetic costs and increased risk of predation. While some bats perform only short daily movements from their roosts to nearby foraging sites, others engage in seasonal long-distance migrations. We seek to understand how and why bats move through space using a range of methods, such as telemetry and radar observations to detect high altitude flights of bats, and stable isotope analysis to reveal bat migration strategies.
Radar observation of flying bats
We participate actively in many bat conservation projects: mitigation measures for major infrastructure projects, cave closure to preserve cave-dwelling bat colonies, bat-friendly translocation of bat colonies from historical buildings undergoing renovation, etc.
Common bent-wing bats (Minopterus schreibersii)