Seabird Group Seabird Group

Pseudo-egg “fabrication” by Grey-headed Albatrosses Thalassarche chrysostoma on Marion Island

Stefan Schoombie* ORCID logo and Janine Schoombie ORCID logo

1 FitzPatrick Institute of African Ornithology, DST-NRF Centre of Excellence, University of Cape Town, Rondebosch, 7701, South Africa

Full paper


Pseudo-eggs are foreign objects, resembling eggs, found inside the nests of birds (Conover 1985) and have been recorded in several ground-nesting seabirds (Coulter 1980; Conover 1985; Mellink 2002; DeStefano et al. 2013; Wagner et al. 2013; Witteveen et al. 2015). They are more common among species that have larger clutches or multiple brood patches (Coulter 1980; Wagner et al. 2013) where pseudo-eggs are included to increase their clutch size (Coulter 1980; Conover 1985; Wagner et al. 2013; Witteveen et al. 2015). Albatrosses and petrels however, only lay one egg; rare two-egg clutches result from two females laying in the same nest, with one of them being an inexperienced breeder (Ryan et al. 2007). The occurrence of pseudo-eggs has only been reported for Laysan (Phoebastria immutabilis) and Black-footed Albatrosses (P. nigripes; Bartholomew & Howell 1964; Grant 1982). We did not find any record of albatrosses breeding in the Southern Ocean that exhibited pseudo-eggs.


We thank Peter Ryan for useful comments while drafting this manuscript. Logistical and financial support was provided by the South African Department of Environmental Affairs, through the South African National Antarctic Programme (SANAP), the National Research Foundation and the University of Cape Town. We thank two anonymous reviewers whose comments improved a previous draft of this manuscript.


ACAP 2015. Grey-headed Albatross Thalassarche chrysostoma. Agreement on the Conservation of Albatrosses and Petrels: 18 pp. http// downloaded 31 May 2015.

Bartholomew, G. A. & Howell, T. R. 1964. Experiments on nesting behaviour of Laysan and Black-footed albatrosses. Animal Behaviour 12: 549–558. [Crossref]

Conover, M. R. 1985. Foreign objects in bird nests. Auk 102: 696–700.

Coulter, M. C. 1980. Stones: An important incubation stimulus for gulls and terns. Auk 97: 898–899.

DeStefano, S., Koenen, K. G. K. & Pereira J. W. 2013. Common Loon incubates rocks as surrogates for eggs. Northeastern Naturalist 20: 143–147. [Crossref]

Grant, G. S., Pettit, T. D., Rahn, H., Whittow, G. C. & Paganelli, C. V. 1982. Water loss from Laysan and Black-footed albatross eggs. Physiological Zoology 55: 405–414. [Crossref]

Mellink, E. 2002. Pseudo-eggs of Brown Sula leucogaster and Blue-footed S. nebouxii Boobies in the Gulf of California, Mexico. Marine Ornithology 30: 43–44.

Ryan, P. G. & Bester, M. N. 2008. Pelagic predators. In: Chown, S. L. & Froneman, P. W. (eds.) The Prince Edward Islands: land-sea interactions in a changing ecosystem: 121–164. SUN PRESS, Stellenbosch. [Crossref]

Ryan, P. G., Phillips, R. A., Nel, D. C. & Wood, A. G. 2007. Breeding frequency in Greyheaded Albatrosses. Ibis 149: 45–52. [Crossref]

Shaffer, S. A., Clatterbuck, C. A., Kelsey, E. C., Naiman, A. D., Young, L. C., VanderWerf, E. A., Warzybok, P., Bradley, R., Jahncke, J. & Bower, G. C. 2014. As the egg turns: Monitoring egg attendance behavior in wild birds using novel data logging technology. PLoS ONE 9: e97898. [Crossref]

Sugden, J. W. 1947. Exotic eggs in nests of California gulls. Condor 49: 93–96. [Crossref]

Tickell, W. L. N. 2000. Albatrosses. Pica Press, Sussex.

Twomey, A. C. 1948. California gulls and exotic eggs. Condor 50: 97–100. [Crossref]

Wagner, E. L., Lee, E. J., Boersma, P. D. 2013. Patterns of acceptance of artificial eggs and chicks by Magellanic Penguins (Spheniscus magellanicus). Journal of Ornithology 154: 99–105. [Crossref]

Witteveen, M., Brown, M. & Ryan, P. G. 2015. Pseudo-egg and exotic egg adoption by Kelp Gulls Larus dominicanus vetula. African Zoology 50: 59–61. [Crossref]