Breeding Biology and Twinning Experiments of Rhinocerous auklets on Cleland Island
The second part of the experiment was to test Lack’s hypothesis that the clutch size of a bird species is determined through evolution by the average number of young the parents are able to fledge.
K.R. Summers and R.H. Drent authored this paper for the Murrelet Vol 60, No 1 Spring 1979
See the full PDF here: The Murrelet 1979