Figures & data
Figure 1 Red-tailed tropicbirds Phaethon rubricauda at breeding sites on North Meyer Islet, Kermadec Group, New Zealand (photos taken by SMHI, April 2008).
Table 1 Morphological measurements [mm] (mean±standard deviation) of chicks and adults, and sexual size dimorphism (SD=[xbar] male/[xbar] female *100) of adult Phaethon rubricauda breeding on North Meyer Islet, Kermadec Group, measured in April 2008.
Table 2 Means and medians of perceived differences between all possible male-male and male-female comparisons of red-tailed tropicbirds Phaethon rubricauda in our sample.
Table 3 Chromatic and achromatic plumage reflectance in male and female tropicbirds Phaethon rubricauda breeding on the Kermadec Islands.
Table 4 Translated amino acid sequence of SWS1 opsin of illustrative species of Phaethontidae (red-tailed tropicbird Phaethon rubricauda), Laridae, Columbidae, Phoenicopteridae, Accipitridae, and seabird families of the Pelecaniformes; SWS1 region shown is that which contains three residues critical in spectral tuning.
Figure 2 Plumage spectrograms from male and female, adult and chick Phaethon rubricauda breeding on the Kermadec Islands; adult spectrograms plotted as means from eight males and six females, respectively, standard errors plotted every 50 nm; averages for white and dark spots from two feathers shown for one male and one female chick.
Figure 3 Just noticeable differences (JNDs) between three randomly assigned male-male and male-female pairs of red-tailed tropicbirds in chromatic and achromatic parameters; means±standard errors plotted; asterisks mark JNDs significantly different to 1.
