Animals constantly interact with their environment. They have to adjust to changes in their social environment, to seasonal changes and to stressors, such as predators or inclement weather. These adjustments are often mediated by hormones that help individuals to respond adequately to environmental variation. Today humans have penetrated almost any habitat on the planet and this has far reaching consequences for the animals living there. While some species are able to cope, others are not and they are in decline. I am interested in the interplay between behavior and hormones in different environments and whether and how animals respond behaviourally and physiologically to anthropogenic habitat change. I use birds as model systems and comparative and experimental approaches to study, for example, the role of hormones (testosterone and corticosterone) as mediators of reproductive behaviors (e.g. territorial behavior, song and parental care) and stress hormones (e.g. corticosterone) as indicators of environmental stress in animal populations. Recently I have also become interested in ways to enhance biodiversity in cities.

Cousseau L, Hammers M,Van de Loock D, Apfelbeck B, Githiru M,Matthysen E, Lens L. (2020) Habitat fragmentation shapes natal dispersal and sociality in an Afrotropical cooperative breeder. Proceedings of the Royal Society B: Biological Sciences 287: 20202428. https://doi.org/10.1098/rspb.2020.2428

Habel JC, Nzau JM, Apfelbeck B, Bendzko T, Fischer C, Kimatu JN, Mwakumanya MA, Maghenda M, Mulwa RK, Rieckmann M, Shauri H, Teucher M, Schmitt C (2020)  Land scarcity, communication gaps and institutional confusions influence the loss of biodiversity in south-eastern Kenya.Biodiversity and Conservation. https://doi.org/10.1007/s10531-020-02043-0

Teucher M, Schmitt CB, Wiese A, Apfelbeck B, Maghenda M, Pellikka P, Lens L, Habel JC (2020) Behind the fog: Forest degradation despite logging bans in an East African cloud forest. Global Ecology and Conservation 22:e01024 https://doi.org/10.1016/j.gecco.2020.e01024

Apfelbeck B, Snep RPH, Hauck TE, Ferguson J, Holy M, Jakoby C, MacIvor JS, Schär L, Taylor M, Weisser WW (2020) Designing wildlife-inclusive cities that support human-animal co-existence. Landscape and Urban Planning, 200: 103817. https://doi.org/10.1016/j.landurbplan.2020.103817

Apfelbeck B, Jakoby C, Hanusch M, Steffani EB, Hauck TE, Weisser WW (2019) A Conceptual Framework for Choosing Target Species for Wildlife-Inclusive Urban Design. Sustainability 11: 6972 https://doi.org/10.3390/su11246972

Apfelbeck B, Hauck TE, Jakoby C, Piecha J, Rogers R, Schröder A, Weisser WW (2019) Animal-Aided Design im Wohnumfeld. Einbeziehung der Bedürfnisse von Tierarten in die Planung und Gestaltung städtischer Freiräume. Bundesamt für Naturschutz, Bonn.https://www.bfn.de/fileadmin/BfN/planung/siedlung/Dokumente/AAD_Broschuere.pdf

Jakoby, C., Rogers, R., Apfelbeck, B., Hauck T.E., Weisser, W.W. 2019 Die Bewertung von Wildtieren durch Wohnungsbaugesellschaften im Wohnumfeld. Natur und Landschaft 5.

Apfelbeck, B., M. F. Haussmann, W. Boner, H. Flinks, K. Griffiths, J. C. Illera, K. G. Mortega, Z. Sisson, P. Smiddy, and B. Helm. 2018 Divergent patterns of telomere shortening in tropical compared to temperate stonechats. Ecology and Evolution 9, 511-521.

Apfelbeck, B., B. Helm, J. C. Illera, K. G. Mortega, P. Smiddy and N. P. Evans. 2017. Baseline and stress-induced levels of corticosterone in male and female Afrotropical and European temperate stonechats during breeding. BMC Evolutionary Biology 17:114.

Apfelbeck, B., K. G. Mortega, H. Flinks, J. C. Illera and B. Helm. 2017. Testosterone, territorial response, and song in seasonally breeding tropical and temperate stonechats. BMC Evolutionary Biology 17:101

Apfelbeck, B., H. Flinks and W. Goymann. 2017. Territorial aggression does not feed back on testosterone in a multiple-brooded songbird species with breeding and non-breeding season territoriality, the European stonechat. Hormones and Behavior 87:89-95.

Apfelbeck, B., H. Flinks and W. Goymann. 2016. Variation in circulating testosterone during mating predicts reproductive success in a wild songbird. Frontiers Ecology And Evolution 4:107.

Goymann, W., C. P. Villavicencio and B. Apfelbeck. 2015. Does a short-term increase in testosterone affect the intensity or persistence of territorial aggression? - An approach using an individual's hormonal reactive scope to study hormonal effects on behavior. Physiology & Behavior 149:310-316. Read more on ATLAS of Science.

Villavicencio, C. P., B. Apfelbeck and W. Goymann. 2014. Parental care, loss of paternity and circulating levels of testosterone and corticosterone in a socially monogamous song bird. Frontiers in Zoology 11:1-13.

Apfelbeck, B., K. Mortega, S. Kiefer, S. Kipper, M. Vellema, C. P. Villavicencio, M. Gahr and W. Goymann. 2013. Associated and disassociated patterns in hormones, song, behavior and brain receptor expression between life-cycle stages in male black redstarts, Phoenicurus ochruros. General and Comparative Endocrinology 184:93-102.

Apfelbeck, B., K. G. Mortega, S. Kiefer, S. Kipper and W. Goymann. 2013. Life-history and hormonal control of aggression in black redstarts: Blocking testosterone does not decrease territorial aggression, but changes the emphasis of vocal behaviours during simulated territorial intrusions. Frontiers in Zoology 10:1-15.

Villavicencio, C. P., B. Apfelbeck and W. Goymann. 2013. Experimental induction of social instability during early breeding does not alter testosterone levels in male black redstarts, a socially monogamous songbird. Hormones and Behavior 64:461-467.

Apfelbeck, B., S. Kiefer, K. G. Mortega, W. Goymann and S. Kipper. 2012. Testosterone affects song modulation during simulated territorial intrusions in male black redstarts (Phoenicurus ochruros). PLoS ONE 7:e52009.

Apfelbeck, B. and W. Goymann. 2011. Ignoring the challenge? Male black redstarts (Phoenicurus ochruros) do not increase testosterone levels during territorial conflicts but they do so in response to gonadotropin-releasing hormone. Proceedings of the Royal Society of London B: Biological Sciences 278:3233-3242.

Apfelbeck, B., J. Stegherr and W. Goymann. 2011. Simulating winning in the wild - The behavioral and hormonal response of black redstarts to single and repeated territorial challenges of high and low intensity. Hormones and Behavior 60:565-571.