Stefan and Janine Schoombie (FitzPatrick Institute, Rondebosch, University of Cape Town, South Africa) have published in Seabird, the annual journal of the United Kingdom-based Seabird Group, on a Grey-headed Albatross Thalassarche chrysostoma incubating an egg-shaped mass of vegetation on Marion Island.
The paper considers this observation in the light of other records of seabirds incubating “pseudo-eggs”, including stones, bones, light bulbs and even beer cans*, and the several hypotheses as to how this habit may come about.
*and sea shells (JC pers. obs.)
A Grey-headed Albatross rises from incubating its pseudo-egg, photograph by Stefan Schoombie
With thanks to Stefan Schoombie.
Reference:
Schoombie, S. & Schoombie, J. 2017. Pseudo-egg “fabrication” by Grey-headed Albatrosses Thalassarche chrysostoma on Marion Island. Seabird 30: 71-74.
John Cooper, ACAP Information Officer, 17 April 2018