Figures 4 and 5 and Tables 3, 4 - Proceedings of the Royal Society B

ELECTRONIC APPENDIX
Dark nests and egg colour in birds: a possible functional role of ultraviolet reflectance in
egg detectability
Jesús M. Avilés*, Juan J. Soler, and Tomás Pérez-Contreras

Appendix. Figure 1. Phylogeny of birds used to calculate independent contrasts.
Carduelis carduelis
Carduelis flavirostris
Carduelis cannabina
Chloris chloris
Carpodacus erythrinus
Coccothraustes coccothraustes
Pyrrhula pyrrhula
Fringilla coelebs
Fringilla montifringilla
Emberiza citrinella
Emberiza melanocephala
Emberiza hortulana
Emberiza cia
Emberiza cirlus
Emberiza schoeniclus
Miliaria calandra
Calcarius lapponicus
Plectrophenax nivalis
Anthus pratensis
Anthus cervinus
Anthus campestris
Motacilla flava
Motacilla alba
Motacilla cinerea
Prunella modularis
Passer domesticus
Passer montanus
Alauda arvensis
Galerida cristata
Eremophila alpestris
Callandrella brachydactyla
Lullula arborea
Acrocephalus paludicola
Acrocephalus schoenobaenus
Acrocephalus arundinaceus
Acrocephalus palustris
Acrocephalus scirpaceus
Hippolais olivetorum
Hippolais icterina
Phylloscopus sibilatrix
Phylloscopus trochilus
Phylloscopus collybita
Phylloscopus bonelli
Sylvia atricapilla
Sylvia borin
Sylvia cantillans
Sylvia melanocephala
Sylvia communis
Sylvia curruca
Sylvia nisoria
Sylvia hortensis
Locustella naevia
Locustella fluviatilis
Regulus regulus
Regulus ignicapillus
Riparia riparia
Delichon urbica
Troglodytes troglodytes
Oenanthe isabellina
Oenanthe hispanica
Oenanthe pleschanka
Oenanthe oenanthe
Phoenicurus ochrurus
Phoenicurus phoenicurus
Luscinia megarhynchos
Luscinia svecica
Erithacus rubecola
Saxicola rubetra
Saxicola torquata
Cercotrichas galactotes
Ficedula hypoleuca
Muscicapa striata
Turdus torquatus
Turdus viscivorus
Turdus iliacus
Turdus philomelos
Turdus pilaris
Turdus merula
Sturnus vulgaris
Cinclus cinclus
Bombycilla garrulus
Lanius excubitor
Lanius senator
Lanius minor
Lanius collurio
Cyanopica cyanus
Pica pica
Corvus corone
Corvus corax

Appendix. Figure 2. Mean reflectance spectra of starling eggs (a) before the treatment
(black line, n = 7), (b) after the treatment with an ultraviolet light-blocker (weak grey, n
= 4) and (c) after the treatment with the control treatment (dark grey, n = 3).
spectral reflectance (%)
80
70
60
50
40
30
20
10
UV
0
300 400
500
600
700
wavelength (nm)

Appendix. Table 1. Information in which comparative analysis was based. See main text for sources of data.
Species N Reflect (UV) Reflect (Blue) Reflect (Green) Reflect (Yellow) Reflect (Red) nesting site habitat type body mass clutch size nestling period
Lanius excubitor 3 1716.00 1613.18 2354.95 2602.07 2862.59 3 2 68 6 20
Lanius collurio 27 3483.17 3335.79 4190.36 4678.50 4954.89 3 1 35 6 14
Lanius minor 2 2317.85 2622.63 3732.70 4180.52 4446.79 3 1 53 6 14
Lanius senator 8 2606.93 2632.00 3480.54 3907.18 4186.42 3 2 30 6 20
Cyanopica cyanus 20 2587.42 2248.55 3083.72 3587.35 3889.05 3 3 75 6 15
Pica pica 7 1823.35 1621.41 2174.41 2558.17 2918.72 2 2 225 6 25
Corvus corone 26 1471.55 1508.27 2157.63 2246.47 2541.64 3 2 570 5 31
Corvus corax 145 2570.04 2263.95 2873.25 2737.45 2906.26 3 2 1150 5 38
Bombicilla garrulus 16 2803.53 2935.85 3422.83 3496.06 3707.27 3 3 54 5 16
Cinclus cinclus 28 5235.07 5578.21 6104.79 6237.15 6211.57 2 1 65 5 23
Turdus torquatus 28 2035.28 1884.52 2392.14 2669.55 3188.13 3 1 110 5 14
Turdus merula 32 2229.59 1975.48 2528.78 2799.69 3310.95 3 2 95 4 14
Turdus pilaris 34 2124.29 1857.00 2352.55 2673.44 3207.74 3 2 110 5 14
Turdus philomelos 30 2685.47 3100.02 3858.31 3307.42 3424.59 3 3 78 4 14
Turdus iliacus 34 1873.87 1717.29 2265.87 2417.95 2847.29 3 3 65 6 13
Turdus viscivorus 26 2491.05 2206.67 2685.95 3055.34 3507.72 3 2 125 4 15
Ficedula hypoleuca 43 3143.32 3550.76 4196.23 4039.40 4305.10 1 3 13 7 15
Muscicapa striata 50 2296.88 1996.19 2559.18 3233.40 3943.12 2 3 16 5 14
Oenanthe isabellina 4 4274.39 4494.23 5121.85 4775.73 4887.41 1 1 29 5 14
Oenanthe oenanthe 50 4242.45 4362.80 4983.61 4759.88 4934.70 1 1 24 6 15
Oenanthe pleschanka 4 3211.15 3595.74 4273.78 3876.77 4092.08 1 1 19 5 13
Oenanthe hispanica 3 3146.96 3474.10 4122.79 3772.34 3968.01 2 1 18 5 13
Phoenicurus ochrurus 32 5422.50 5184.10 5586.78 5724.77 5732.62 1 2 17 5 15
Phoenicurus phoenicurus 217 2675.55 3191.70 3849.34 3369.87 3607.09 1 2 16 6 15
Luscinia megarhynchos 30 1184.08 934.65 1295.18 1636.87 2179.15 3 2 23 5 13
Luscinia svecica 36 1836.97 1566.94 2139.96 2511.97 3074.96 3 2 19 6 14
Erithacus rubecula 95 3758.16 3093.47 3928.73 4801.02 5381.57 2 3 19 5 14
Saxicola rubetra 78 1982.42 2382.69 3046.28 2632.65 2906.82 3 1 20 6 13
Saxicola torquata 16 2486.95 2555.86 3257.97 3320.75 3714.81 3 1 16 6 15
Cercotrichas galactotes 2 3922.16 3650.51 4339.46 4784.36 5146.55 3 1 24 5 12
Sturnus vulgaris 82 5527.35 4717.77 5150.53 4716.20 4789.97 1 2 83 5 21

Troglodytes troglodytes 99 5825.24 5533.28 5977.13 6148.15 6201.00 1 2 11 6 17
Riparia riparia 38 5422.79 5221.17 5662.29 5827.31 5842.31 1 1 15 5 19
Delichon urbica 32 6307.91 5763.00 6140.43 6218.92 6210.97 1 1 18 5 21
Regulus regulus 7 3325.55 3117.55 4046.22 4687.94 4936.68 2 3 6 8 19
Regulus ignicapillus 5 2926.89 2431.23 3217.73 4240.95 4903.00 2 3 6 8 20
Locustella naevia 20 3425.55 2981.21 3373.68 4029.03 4658.66 3 1 13 6 12
Locustella fluviatilis 3 3099.79 2784.12 3205.38 3703.72 4146.04 3 1 19 6 14
Acrocephalus paludicola 4 3402.95 3351.10 3987.74 4151.69 4314.04 3 1 12 6 13
Acrocephalus schoenobaenus 239 1917.63 1360.95 2020.01 2624.62 2970.23 3 1 12 6 13
Acrocephalus arundinaceus 205 2946.77 2934.29 3580.63 3525.80 3713.91 3 1 31 5 12
Acrocephalus palustris 126 3177.81 3025.84 3674.63 3814.25 4011.30 3 1 13 5 12
Acrocephalus scirpaceus 1807 2098.56 1823.42 2484.09 2776.91 3041.03 3 1 12 4 12
Hippolais olivetorum 3 3482.41 3022.96 3300.36 3899.72 4658.49 3 2 18 4 12
Hippolais icterina 4 4443.45 3156.32 3286.17 3992.19 4931.83 3 2 14 5 13
Phylloscopus sibilatrix 12 3567.53 2983.98 3292.53 3664.07 3950.30 1 2 10 6 12
Phylloscopus bonelli 3 2322.75 2056.39 2620.88 3286.45 3903.66 2 3 8 5 13
Phylloscopus collibita 13 4799.28 4465.84 4914.10 5205.56 5305.27 2 2 8 6 14
Phylloscopus trochilus 33 4815.35 4345.04 4888.41 5390.54 5652.88 2 2 8 7 14
Sylvia melanocephala 8 2665.98 2357.29 3073.69 3801.58 4319.65 3 2 11 4 12
Sylvia hortensis 6 2638.68 2016.49 2728.31 3375.18 3754.33 3 2 22 5 12
Sylvia nisoria 20 3746.52 3143.57 3910.86 4410.39 4661.13 3 2 28 5 14
Sylvia curruca 44 3361.66 3319.90 4066.20 4357.16 4589.07 3 2 13 5 11
Sylvia communis 276 2433.98 1989.58 2838.45 3342.48 3645.29 3 2 15 5 12
Sylvia cantillans 4 2494.32 1936.14 2508.92 3336.89 3921.19 3 2 12 4 12
Sylvia atricapilla 63 3162.71 2558.02 3337.51 3954.78 4321.91 3 2 17 5 12
Sylvia borin 62 2890.01 2409.48 3143.76 3684.87 3994.05 3 2 20 5 10
Eremophila alpestris 26 1832.39 1608.12 2271.89 2772.11 3136.14 3 1 37 4 12
Alauda arvensis 36 2366.24 1959.20 2514.73 2944.77 3255.80 3 1 37 4 19
Galerida cristata 30 2503.44 2075.72 2684.60 3261.30 3632.27 3 1 40 4 14
Callandrella brachidactila 3 2325.01 2225.24 2911.40 3345.19 3642.63 3 1 23 4 12
Lullula arborea 30 1935.84 1610.91 1922.63 2425.55 3102.55 3 1 30 4 14
Passer domesticus 95 4169.14 3266.17 3606.67 3750.99 3898.73 1 1 27 5 15
Passer montanus 3 1296.40 1199.66 1464.57 1793.92 2092.75 1 2 22 5 13

Anthus pratensis 212 1577.24 1169.14 1444.52 1825.91 2165.89 3 1 21 5 14
Anthus campestris 40 1872.21 1471.41 1834.50 2252.34 2584.51 3 1 24 5 13
Anthus cervinus 2 1117.00 814.52 1066.82 1469.81 1875.04 3 1 20 6 13
Motacila flava 205 2190.37 1735.15 2269.12 2887.70 3358.13 3 1 19 6 13
Motacilla cinerea 32 3008.86 2559.66 3261.64 3927.14 4380.26 2 1 19 5 12
Motacilla alba 184 3351.15 3138.27 3631.53 3897.24 4132.89 2 1 23 6 15
Prunella modularis 111 2340.20 2933.04 3576.23 2916.66 3080.86 3 2 17 5 12
Fringilla coelebs 28 2270.78 2213.77 2686.72 2975.82 3409.32 3 2 22 5 14
Fringilla montefringilla 37 1998.16 1935.55 2437.04 2669.34 3092.36 3 3 26 6 14
Carduelis carduelis 5 3817.11 4169.24 4952.75 4984.18 5248.85 3 2 16 6 14
Carduelis cannabina 3 2968.83 3215.64 3847.55 4099.22 4384.63 3 2 18 5 12
Carduelis flavirostris 5 2861.85 3036.68 3676.79 3808.03 4063.67 3 1 15 6 15
Chloris chloris 12 3587.66 3724.31 4363.75 4642.20 4922.61 3 2 30 5 15
Carpodactus erhytrinus 9 2409.08 2918.96 3555.77 3101.21 3303.74 3 2 23 5 14
Pyrrhula pyrrhula 7 3320.47 3661.03 4319.26 4087.87 4316.47 3 2 24 5 14
Coccothraustes coccothraustes 4 2777.21 2906.90 3546.90 3636.32 3843.44 3 3 52 5 13
Calcarius laponicus 2 1765.85 1618.88 2041.35 2345.40 2678.84 3 1 24 5 10
Plectrophenax nivalis 82 4477.67 3555.10 4054.94 4290.45 4621.42 1 1 34 5 12
Miliaria calandra 4 3118.49 3315.28 3921.79 4194.68 4468.57 3 1 47 4 13
Emberiza citrinella 34 2783.00 2485.09 2861.48 3257.11 3677.13 3 2 27 4 13
Emberiza schoeniclus 3 1693.40 1434.62 1813.71 2125.95 2387.25 3 1 19 5 13
Emberiza cirlus 2 2155.33 1892.79 2245.61 2529.87 2832.76 3 2 24 4 12
Emberiza cia 4 3368.93 2994.28 3439.75 3785.34 4111.49 3 2 25 5 12
Emberiza hortulana 2 2638.46 2812.80 3358.16 3770.09 4128.59 3 1 23 5 13
Emberiza melanocephala 2 3556.46 3524.18 3888.74 3977.26 4152.00 3 1 28 5 14

Appendix
Table 2. Percentage of variance in egg colour traits and nesting habits at different
taxonomic levels, based on variance component analyses.
Brightness Blue-red Ultraviolet Nesting habit
Family 18.4 10.6 25.2 23.1
Genus 29.6 35.9 26.0 17.1
Species 52.0 53.5 48.8 59.8

Appendix
Table 3. Results of general linear models including PC3 scores (i.e. ultraviolet colour) as
dependent variables and nesting site, habitat type, body mass, clutch size, duration of the
nestling period and PC2 scores (i.e. blue-red colour) as independent variables. Analyses
were performed on raw data (i.e. species as independent data points) and on
phylogenetically independent contrasts. In the last case the regression line was forced
through the origin and degrees of freedom were corrected by subtracting the number of
polytomies in the phylogenetic tree.
Variables in
F df P Beta (SE) t P
the model
Raw data Intercept 4.63 1,82 0.03 2.15 0.03
nesting site 6.61 1,82 0.01 -0.31 0.12 -2.57 0.01
habitat type 0.81 1,82 0.37 -0.09 0.10 -0.90 0.37
body mass 0.008 1,82 0.92 0.01 0.16 0.09 0.92
clutch size 3.99 1,82 0.04 -0.24 0.12 -1.99 0.05
nestling period 0.0001 1,82 0.99 0.001 0.15 0.01 0.99
PC2 (blue versus red) 1.06 1,82 0.30 -0.12 0.11 -1.03 0.30
Contrast nesting site 8.89 1,53 0.004 -0.32 0.11 -2.98 0.003
habitat type 0.32 1,53 0.57 -0.06 0.10 -0.56 0.57
body mass 2.45 1,53 0.12 0.20 0.13 1.56 0.12
clutch size 0.33 1,53 0.56 -0.06 0.11 -0.57 0.56
nestling period 0.26 1,53 0.60 0.06 0.12 0.51 0.60
PC2 (blue versus red) 0.61 1,53 0.43 -0.08 0.11 -0.78 0.43