Goymann, W.; Schwabl, H.: The tyranny of phylogeny - A plea for a less dogmatic stance on two-species comparisons. Bioessays 43 (8), 2100071 (2021)

Greives, T. J.; Eshleman, M.; Galante, H.; Elderbrock, E. K.; Deimel, C.; Hau, M.: Early nighttime testosterone peaks are correlated with GnRH-induced testosterone in a diurnal songbird. General and Comparative Endocrinology 312, 113861 (2021)

Hotta, T.; Awata, S.; Jordan, L. A.; Kohda, M.: Subordinate fish mediate aggressiveness using recent contest information. Frontiers in Ecology and Evolution 9, 685907 (2021)

Huffeldt, N. P.; Tigano, A.; Erikstad, K. E.; Goymann, W.; Jenni-Eiermann, S.; Moum, T.; Reiertsen, T. K.: The relationship between daily behavior, hormones, and a color dimorphism in a seabird under natural continuous light. Hormones and Behavior 130, 104930 (2021)

Husak, J. F.; Fuxjager, M. J.; Johnson, M. A.; Vitousek, M. N.; Donald, J. W.; Francis, C. J.; Goymann, W.; Hau, M.; Kircher, B. K.; Knapp, R. et al.; Martin, L. B.; Miller, E. T.; Schoenle, L. A.; Williams, T. D.: Life history and environment predict variation in testosterone across vertebrates. Evolution: International journal of organic evolution 75 (5), pp. 1003 - 1010 (2021)

Jax, E.; Mueller, I.; Börno, S.; Borlinghaus, H.; Eriksson, G.; Fricke, E.; Timmermann, B.; Pendl, H.; Fiedler, W.; Klein, K. et al.; Schreiber, F.; Wikelski, M.; Magor, K. E.; Kraus, R. H. S.: Health monitoring in birds using bio‑loggers and whole blood transcriptomics. Scientific Reports 11, 10815 (2021)

Knief, U.; Forstmeier, W.: Violating the normality assumption may be the lesser of two evils. Behavior Research Methods 53 (6), pp. 2576 - 2590 (2021)

Knief, U.; Forstmeier, W.; Kempenaers, B.; Wolf, J. B. W.: A sex chromosome inversion is associated with copy number variation of mitochondrial DNA in zebra finch sperm. Royal Society Open Science 8 (9), 211025 (2021)

Ko, M.-C.; Frankl-Vilches, C.; Bakker, A.; Gahr, M.: The gene expression profile of the song control nucleus HVC shows sex specificity, hormone responsiveness, and species specificity among songbirds. Frontiers in Neuroscience 15, 680530 (2021)

Koch, R. E.; Buchanan, K. L.; Casagrande, S.; Crino, O.; Dowling, D. K.; Hill, G. E.; Hood, W. R.; McKenzie, M.; Mariette, M. M.; Noble, D. W. A. et al.; Pavlova, A.; Seebacher, F.; Sunnucks, P.; Udino, E.; White, C. R.; Salin, K.; Stier, A.: Integrating mitochondrial aerobic metabolism into ecology and evolution. Trends in Ecology and Evolution 36 (4), pp. 321 - 332 (2021)

Küblbeck, M.; Feulner, J.: "Müssen wir nicht größer denken?" Nachgedanken zum 2. Braunkehlchen-Symposium. Ornithologischer Anzeiger 60 (1), pp. 103 - 107 (2021)

Küblbeck, M.; Liebel, H.; Goymann, W.: Was zeichnet ein gutes Braunkehlchen-Gebiet aus? Zur Einschätzung der Habitatqualität. Ornithologischer Anzeiger 60 (1), pp. 90 - 94 (2021)

Kuhl, H.; Frankl-Vilches, C.; Bakker, A.; Mayr, G.; Nikolaus, G.; Boerno, S. T.; Klages, S.; Timmermann, B.; Gahr, M.: An unbiased molecular approach using 3’-UTRs resolves the avian family-level tree of life. Molecular Biology and Evolution 38 (1), pp. 108 - 127 (2021)

Kupan, K.; Székely, T.; Cruz-López, M.; Seymour, K.; Küpper, C.: Offspring desertion with care? Chick mortality and plastic female desertion in Snowy Plovers. Behavioral Ecology 32 (3), pp. 428 - 439 (2021)

Laitly, A.; Callaghan, C. T.; Delhey, K.; Cornwell, W. K.: Is color data from citizen science photographs reliable for biodiversity research? Ecology and Evolution 11 (9), pp. 4071 - 4083 (2021)

Lardy, R.; de Boyer des Roches, A.; Capdeville, J.; Bastien, R.; Mounier, L.; Veissier, I.: Refinement of international recommendations for cubicles, based on the identification of associations between cubicle characteristics and dairy cow welfare measures. Journal of Dairy Science 104 (2), pp. 2164 - 2184 (2021)

Leitner, S.; Brighton, R.; Voigt, C.: Barred buttonquail males outlive females. Journal of Avian Biology 52 (10), e02722 (2021)

Lemazina, A.; Trost, L.; Gahr, M.; Hoffmann, S.: The multifaceted vocal duets of white-browed sparrow weavers are based on complex duetting rules. Journal of Avian Biology 52 (9), e02703 (2021)

Lewanzik, D.; Goerlitz, H. R.: Task-dependent vocal adjustments to optimize biosonar-based information acquisition. The Journal of Experimental Biology 224 (1), jeb234815 (2021)

Li, X.-Y.; Morozov, A.; Goymann, W.: Coevolution of female fidelity and male help in populations with alternative reproductive tactics. Proceedings of the Royal Society B: Biological Sciences 288 (1943), 20202371 (2021)