Home News Archive - MPI for Ornithology The brains of birds synchronize when they sing duets Publications of Michael R. Hall All genres Journal Article (2) Journal Article (2) 1987 Journal Article Hall, M. R.: External stimuli affecting incubation behavior and prolactin secretion in the duck (anas-platyrhynchos). Hormones and Behavior 21 (3), pp. 269 - 287 (1987) MPG.PuRe DOI 1986 Journal Article Reyer, H.-U.; Dittami, J.; Hall, M. R.: Avian helpers at the nest: Are they psychologically castrated? Ethology 71 (3), pp. 216 - 228 (1986) MPG.PuRe DOI