Zoelzer, F. et al. 2020. A comparative study of nightly allonursing behaviour in four zoo-housed groups of giraffes (Giraffa camelopardalis) . Journal of Zoo and Aquarium Research. 8, 3 (Jul. 2020), 175–180. DOI:https://doi.org/10.19227/jzar.v8i3.508.