Do polyandrous shorebirds trade off egg size with egg number?

Classical polyandry in birds is rare and is most frequent in the shorebirds (Charadriiformes). Polyandrous shorebirds lay smaller eggs for their body masses than non‐polyandrous shorebirds, indicating that polyandrous female shorebirds may trade egg size off against number of eggs in order to maximize reproductive success. However, this trade‐off may be confounded by phylogeny because most polyandrous species belong to a single family, the Jacanidae. I re‐analysed this adaptive hypothesis using phylogenetically‐independent contrast analyses. These analyses showed that there was no statistically significant difference in egg size between polyandrous and monogamous shorebirds once the effects of phylogeny had been incorporated. This is one of the first studies to show that the results of independent contrasts analyses differ from those where phylogenetic effects have not been taken into account.