Remarks on the terminology used to describe developmental behaviour among the auks (Alcidae), with particular reference to that of the Great Auk Pinguinus impennis

Much of the historical record relating to the breeding biology of the Great Auk Pinguinus impennis consists of statements on which it is not safe to rely without corroboration. There is, nevertheless, sufficient evidence for a strong case to be argued for the species having evolved a precocial chick‐rearing strategy, together with an incubation period that is remarkably brief for a bird of its size. In this way, the species would have minimized the time for which it had to remain ashore to raise its young. Before the evidence for this proposition is evaluated, a review is undertaken of the history and usage of the terminology most frequently used to describe the developmental condition of young birds on hatching. Modifications to the terminology have been suggested where there is a potential for confusion, and an entirely new term, ‘hypoprecocial’, introduced for downy young that require an appreciable period of brooding before quitting the breeding site. Regarding the species itself, it is suggested that the Great Auk had evolved a strategy that was more fully precocial than that of any seabird whose breeding biology is known to science.