Figure 1.

Comparison of extra-pair mating adaptations in males of the nine Australian Malurus species. For each species we illustrate (a) mean (± SE) size of the cloacal protuberance (CP) of breeding males (SE in M. cyaneus and data on CP size in M. pulcherrimus and M. amabilis were not available (n.a.); numbers depict sample sizes), (b) mean testes size (as % of body mass), (c) male breeding plumage cover (% of the body seasonally covered by colorful plumage), and (d) whether male extra-territorial forays, display behavior and petal presentations to extra-pair females, have been described (ticks) or not (crosses). Data on M. coronatus (dark bars) are from our study, except for testes size [61], and references for other data are given in the 'Methods' section. The phylogeny was obtained from [44].