How did the Great Auk raise its young?

Abstract

The extant auks show three strategies of chick rearing--precocial (chicks leave the nest site when a few days old), intermediate (young raised to a mass of around 20% of adult mass) and semi-precocial (young raised to a mass of around 65% of adult mass). It is not known which strategy the extinct Great Auk used. In this paper, we investigate this issue by a novel combination of a time and energy budget model and phylogenetic comparison. The first approach indicates that for reasonable estimates of the equation parameters, the Great Auk could have followed an intermediate strategy. For a limited range of parameters, the Great Auk could have followed the semi-precocial strategy. Phylogenetic comparison shows that it is unlikely that the Great Auk followed a precocial strategy. The results suggest that the Great Auk followed an intermediate strategy as does its presumed closest extant relative the Razorbill.