Emu 2015 115(2), 89–98 doi: 10.1071/MU14076_AC © BirdLife Australia 2015

Supplementary Material Distinctiveness of subspecies in revealed from disparate patterns of sexual dichromatism, plumage colouration, morphometrics and ancient DNA Anna M. KearnsA,B,E, Lauren C. WhiteC, Jeremy J. AustinC,D and Kevin E. OmlandA AUniversity of Maryland, Baltimore County, Department of Biological Sciences, 1000 Hilltop Circle, Baltimore, Maryland 21250, USA. BNatural History Museum, University of Oslo, PO Box 1172, Blindern, NO-0318, Oslo, Norway. CAustralian Centre for Ancient DNA, School of Earth and Environmental Sciences and Environment Institute, University of Adelaide, North Terrace, Adelaide, SA 5005, Australia. DSciences Department, Museum Victoria, Carlton Gardens, Melbourne, Vic. 3000, Australia. ECorresponding author. Email: [email protected]

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Fig. S1. Paired examples (males left, females right) of the three types of sexually dichromatic plumage found on Vanuatu: (a) typical dichromatism, in which differences between the sexes are marked (subspecies ambrynensis); (b) drab reduced dichromatism, in which males are more like females (subspecies soror, feminina and cognata; subspecies cognata shown); and (c) elaborate reduced dichromatism, in which females are more male-like (subspecies tannensis subsp. nov. of and P. m. similis of Island; subspecies similis shown). Note that males are more elaborately plumaged than females irrespective of the type of sexual dichromatism.

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Fig. S2. Plumage variation of Pacific Robins from Aneityum and Tanna Islands, Vanuatu. Ventral and dorsal plumage of two representative males and two females from each island.

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Table S1. Specimens examined for analyses of morphometrics, plumage colouration and mtDNA Specimens were from the American Museum of Natural History (AMNH), Florida Museum of Natural History (UF) and the Louisiana State University Museum of Natural Science (LSUMNS). Sampling: M, morphometrics; P, plumage colouration; D, mtDNA; S indicates specimen sampled for dataset; –, unsampled. All sequences were deposited in GenBank (accession numbers KP203816– KP203833). Collectors: R. H. Beck and assistants (RHB), 1926–27; L. Macmillan (LM), 1935–37; Florida Museum of Natural History (FMNH), 2002 Sampling Specimen voucher number Island Sex Collector M P D P. m. ambrynensis

LSUMNS-B45776/UF-42869 Female FMNH 2002 S - S LSUMNS-B45780 Espiritu Santo Male FMNH 2002 - - S LSUMNS-B45834 Espiritu Santo Male FMNH 2002 - - S AMNH-212429 Female RHB 1926 S S - AMNH-213914 Female RHB 1926 S S - AMNH-215791 Gaua Female RHB 1926 S S - AMNH-215793 Gaua Female RHB 1926 S S - AMNH-215802 Espiritu Santo Female RHB 1926 S S - AMNH-217520 Ambae Female RHB 1927 S S - AMNH-217521 Ambae Female RHB 1927 S S - AMNH-217522 Ambae Female RHB 1927 S S - AMNH-213558 Paama Male RHB 1926 S S - AMNH-213559 Male RHB 1926 S S - AMNH-213908 Melapau?A Male RHB 1926 S S - AMNH-213909 Gaua Male RHB 1926 S S - AMNH-213910 Gaua Male RHB 1926 S S - AMNH-213911 Gaua Male RHB 1926 S S - AMNH-215787 Gaua Male RHB 1926 S S - AMNH-215788 Gaua Male RHB 1926 S S - AMNH-215789 Gaua Male RHB 1926 S S - AMNH-215790 Gaua Male RHB 1926 S S - AMNH-217516 Ambae Male RHB 1927 S S - AMNH-217517 Ambae Male RHB 1927 S S - AMNH-217518 Ambae Male RHB 1927 S S - AMNH-223667 Male RHB 1926 S S - P. m. cognata

AMNH-336619 Female LM 1937 S - - AMNH-336620 Erromango Female LM 1936 S S - AMNH-336621 Erromango Female LM 1936 S S -

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Sampling Specimen voucher number Island Sex Collector Year M P D AMNH-336622 Erromango Female LM 1936 S S - AMNH-336623 Erromango Female LM 1936 S S - AMNH-336626 Erromango Female LM 1936 S S - AMNH-336852 Erromango Female LM 1936 S S S AMNH-336606 Erromango Male LM 1937 S S - AMNH-336607 Erromango Male LM 1937 S S S AMNH-336608 Erromango Male LM 1936 S S S AMNH-336609 Erromango Male LM 1936 S S - AMNH-336610 Erromango Male LM 1936 S S - AMNH-336612 Erromango Male LM 1936 S S - AMNH-336613 Erromango Male LM 1936 S S - AMNH-336614 Erromango Male LM 1936 S S - AMNH-336616 Erromango Male LM 1936 S S - AMNH-336617 Erromango Male LM 1936 S S - P. m. feminina

AMNH-212412 Female RHB 1926 S S - AMNH-212413 Emae Female RHB 1926 S S - AMNH-212414 Emae Female RHB 1926 S S - AMNH-212415 Emae Female RHB 1926 S S - AMNH-212416 Emae Female RHB 1926 S S - AMNH-212428 Female RHB 1926 S S S AMNH-212404 Emae Male RHB 1926 S S S AMNH-212405 Emae Male RHB 1926 S S - AMNH-212406 Emae Male RHB 1926 S S - AMNH-212407 Emae Male RHB 1926 S S S AMNH-212425 Efate Male RHB 1926 S S - P. m. soror

AMNH-215801 Female RHB 1926 S S S AMNH-215794 Vanua Lava Male RHB 1926 S S - AMNH-215795 Vanua Lava Male RHB 1926 S S - AMNH-215796 Vanua Lava Male RHB 1926 S S S AMNH-215798 Vanua Lava Male RHB 1926 S S S P. m. similis

AMNH-336999 Aneityum Female LM 1937 S S - AMNH-337002 Aneityum Female LM 1937 S S S AMNH-337003 Aneityum Female LM 1937 S S - AMNH-336995 Aneityum Male LM 1937 S S S AMNH-336996 Aneityum Male LM 1937 S S - AMNH-336997 Aneityum Male LM 1937 S S -

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Sampling Specimen voucher number Island Sex Collector Year M P D AMNH-336998 Aneityum Male LM 1937 S S S P. m. tannensis subsp. nov.

AMNH-336853 Tanna Female LM 1936 S S - AMNH-336854 Tanna Female LM 1936 S S - AMNH-336855 Tanna Female LM 1936 S S - AMNH-336856 Tanna Female LM 1935 S - - AMNH-336857 Tanna Female LM 1936 S S S AMNH-336858 Tanna Female LM 1936 S S - AMNH-336842B Tanna Male LM 1936 S S S AMNH-336843 Tanna Male LM 1936 S S - AMNH-336844 Tanna Male LM 1935 S S S AMNH-336845 Tanna Male LM 1935 S - - AMNH-336846 Tanna Male LM 1936 S S - AMNH-336847 Tanna Male LM 1935 S - - AMNH-336848 Tanna Male LM 1935 S S - AMNH-336849 Tanna Male LM 1935 S S - AMNH-336850 Tanna Male LM 1935 S - - AMNH-336851 Tanna Male LM 1935 S - - AAMNH-213908 was collected within the range of subspecies P. m. ambrynensis. However, its exact collection locality is uncertain. BHolotype of P. m. tannensis subsp. nov.

Table S2. Differentiation of the three types of sexual dichromatism in Vanuatu ANOVAs represent separate tests for each sex and plumage tract across the dichromatic, drab and elaborate plumage types. Acronyms are as follows: N, sample size; d.f., degrees of freedom; F, ANOVA F statistic; p, ANOVA p value. Sample sizes (N) are shown in the following order: dichromatic, drab and elaborate plumage types. Significant results of ANOVA after Bonferonni correction (α = 0.05/3 = 0.017) are highlighted in bold Female Male N d.f. F p N d.f. F p brightness 8,13,7 2,25 4.71 0.02 95.61 0.0001 Back saturation 30.55 0.0001 14,18,9 2,38 99.15 0.0001 hue 42.99 0.0001 88.31 0.0001 brightness 8,13,8 2,26 1.53 0.24 30.65 0.0001 Crown saturation 27.06 0.0001 12,19,9 2,37 126.59 0.0001 hue 20.2 0.0001 30.07 0.0001 brightness 7,12,7 2,23 2.65 0.09 119.03 0.0001 Throat saturation 14.94 0.0001 13,18,7 2,35 67.86 0.0001 hue 0.13 0.88 32.49 0.0001

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Table S3. Phenotypic differentiation of drab plumaged soror, cognata and feminina calculated separately for males and females Acronyms are as follows: N, sample size; d.f., degrees of freedom; F, ANOVA F statistic; p, ANOVA p value. Sample sizes are shown in the following order: cognata, feminina and soror. Significant results of ANOVA are highlighted in bold (α = 0.05 for morphometric variables and α = 0.017 for colour variables) Female Male N d.f. F p N d.f. F p Back brightness 6,6,1 2,10 2.5 0.14 9,5,4 2,15 4 0.04 saturation 3.4 0.08 2.7 0.1 hue 2.1 0.17 4.7 0.03 Crown brightness 6,6,1 2,10 4.7 0.04 10,5,4 2,16 4.1 0.04 saturation 2 0.19 0.9 0.45 hue 5.8 0.02 5.3 0.02 Throat brightness 5,6,1 2,9 1.1 0.37 10,5,3 2,17 0.02 0.98 saturation 1.9 0.2 1 0.38 hue 2.1 0.18 1.5 0.27 Breast brightness 6,6,1 2,10 4.7 0.04 10,5,4 2,16 2.2 0.15 saturation 10.8 0.003 3.1 0.07 hue 6.2 0.02 7.4 0.005 Wing length 7,6,1 2,11 2.9 0.1 10,5,4 2,16 6.3 0.01 Tail length 7,6,1 2,11 1 0.38 10,5,4 2,16 5.2 0.02 Bill length 6,6,1 2,10 1.2 0.33 10,5,4 2,16 0.07 0.93

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Table S4. Phenotypic differentiation of elaborate plumaged Aneityum and Tanna populations calculated separately for each sex Acronyms are as follows: N, sample size; d.f., degrees of freedom; t, two tailed t-test statistic; p, t-test p value. Sample sizes are shown in the following order: Aneityum, Tanna. Significant results of t-tests are highlighted in bold (α = 0.05 for morphometric variables and α = 0.017 for colour variables) Female Male N d.f. t p N d.f. t p Back brightness 2, 5 4.4 2.14 0.09 4, 5 6.9 1.13 0.3 saturation 4.2 0.36 0.74 4.3 –1 0.37 hue 4.1 –1.7 0.16 5.7 0.4 0.7 Crown brightness 3, 5 2.8 0.21 0.85 4, 5 5.3 –1.22 0.27 saturation 5.3 –0.41 0.7 4.7 –1.51 0.2 hue 5.1 0.06 0.95 5.9 2.4 0.05 Throat brightness 3, 4 3.2 –2.8 0.06 4, 3 5 –4.6 0.006 saturation 2.4 –0.24 0.83 5 –3.8 0.013 hue 5 –1.39 0.22 5 –1.4 0.22 Breast brightness 3, 5 5.7 –2.1 0.09 4, 6 4.8 –3.9 0.013 saturation 3.7 0.087 0.94 4.4 –0.65 0.55 hue 4.1 –1.1 0.33 6.1 –2.35 0.06 Wing length 3, 6 6.8 –2.77 0.03 4, 10 11.9 0.17 0.87

Tail length 3, 6 6.2 0 1 4, 10 4.6 –0.79 0.47

Bill length 3, 5 6 –2.82 0.03 4, 9 10.1 –3.49 0.006

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