Table 1.
Species means raw data (all measurements in mm)
| Taxon | Activity pattern | n wet | n dry | Orbit depth | Orbit diameter | Sclerotic ring inner diameter | Sclerotic ring max. length | Axial sclerotic ring length | Corneal diameter | Axial length | Head length |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Strigiformes | |||||||||||
| Athene noctua* | photopic | 2 | 1 | 10.28 | 18.92 | 12.46 | 7.95 | 7.01 | 11.52 | 18.27 | 52.90 |
| Athene brama* | photopic | 2 | 7.30 | 18.90 | 10.99 | 7.23 | 5.71 | 10.92 | 17.11 | 46.75 | |
| Glaucidium brasilianum* | photopic | 1 | 1 | 8.57 | 19.73 | 11.95 | 8.26 | 7.54 | 11.44 | 18.05 | 47.73 |
| Glaucidium perlatum | photopic | 1 | 7.89 | 16.99 | 10.97 | 7.63 | 6.82 | 10.97 | 16.80 | 31.38 | |
| Glaucidium jardinii | photopic | 1 | 6.38 | 14.55 | 7.91 | 6.73 | 5.90 | 7.91 | 11.92 | 27.74 | |
| Glaucidium tephronatum | photopic | 1 | 8.69 | 15.54 | 8.99 | 5.24 | 30.04 | ||||
| Bubo africanus | scotopic | 2 | 15.64 | 29.28 | 20.19 | 14.19 | 14.11 | 17.58 | 23.03 | 43.86 | |
| Bubo bubo* | scotopic | 1 | 21.86 | 35.58 | 23.23 | 19.14 | 17.80 | 20.15 | 33.95 | 61.23 | |
| Bubo virginianus* | scotopic | 4 | 18.39 | 38.61 | 23.49 | 18.62 | 17.93 | 57.08 | |||
| Strix aluco | scotopic | 2 | 3 | 16.17 | 25.25 | 17.80 | 12.94 | 12.16 | 15.35 | 24.96 | 67.01 |
| Strix varia* | scotopic | 4 | 13.49 | 29.40 | 17.24 | 11.49 | 9.90 | 47.56 | |||
| Strix occidentalis | scotopic | 1 | 14.28 | 29.65 | 18.52 | 11.58 | 10.09 | 48.66 | |||
| Nyctea scandiaca* | photopic | 1 | 19.91 | 32.29 | 21.33 | 19.87 | 18.58 | 56.02 | |||
| Otus scops* | scotopic | 2 | 8.00 | 16.76 | 10.94 | 6.48 | 5.75 | 9.86 | 13.78 | 41.42 | |
| Otus asio* | scotopic | 1 | 1 | 9.59 | 22.75 | 14.42 | 10.83 | 9.85 | 13.76 | 20.04 | 46.01 |
| Otus rutilis | scotopic | 1 | 8.77 | 19.22 | 12.72 | 8.50 | 7.61 | 12.72 | 17.24 | 32.39 | |
| Otus longicornis | scotopic | 1 | 8.00 | 19.59 | 11.78 | 8.33 | 7.58 | 11.78 | 17.89 | 29.21 | |
| Tyto alba* | scotopic | 5 | 4 | 10.62 | 18.67 | 12.01 | 7.21 | 7.13 | 11.24 | 17.80 | 63.90 |
| Asio flammeus | scotopic | 3 | 9.39 | 19.70 | 12.41 | 6.97 | 60.30 | ||||
| Asio otus | scotopic | 3 | 10.01 | 19.61 | 13.18 | 5.86 | 5.33 | 60.42 | |||
| Ketupa ketupa | scotopic | 1 | 15.59 | 29.65 | 16.62 | 11.48 | 9.64 | 47.47 | |||
| Ketupa zeylonensis | scotopic | 1 | 16.26 | 32.95 | 20.07 | 11.55 | 9.39 | 50.19 | |||
| Scotopelia peli | scotopic | 1 | 21.27 | 34.41 | 22.68 | 12.72 | 6.76 | 102.62 | |||
| Surnia ulula* | scotopic | 1 | 14.24 | 21.95 | 12.13 | 8.59 | 40.03 | ||||
| Podargidae | |||||||||||
| Podargus strigoides* | scotopic | 1 | 1 | 18.43 | 25.40 | 15.06 | 9.73 | 6.40 | 14.11 | 20.23 | 71.34 |
| Aegothelidae | |||||||||||
| Aegotheles insignis* | scotopic | 1 | 3.37 | 13.66 | 8.06 | 4.93 | 8.09 | 9.27 | 21.87 | ||
| Nyctibidae | |||||||||||
| Nyctibius griseus* | scotopic | 1 | 11.26 | 24.21 | 17.48 | 5.93 | 5.28 | 17.48 | 19.24 | 34.35 | |
| Caprimulgidae | |||||||||||
| Caprimulgus europaeus* | scotopic | 1 | 1 | 7.04 | 13.85 | 10.71 | 3.38 | 2.96 | 9.77 | 12.06 | 38.86 |
| Caprimulgus macrurus* | scotopic | 1 | 1 | 5.88 | 15.50 | 10.61 | 2.97 | 2.20 | 10.61 | 12.95 | 34.06 |
| Caprimulgus madagascariensis | scotopic | 1 | 7.90 | 14.11 | 9.02 | 3.36 | 2.54 | 9.02 | 11.42 | 23.55 | |
| Caprimulgus pectoralis | scotopic | 1 | 6.16 | 14.36 | 8.26 | 2.91 | 1.60 | 39.84 | |||
| Macrodiperyx vexillaria | scotopic | 1 | 8.39 | 16.25 | 10.41 | 2.27 | 1.81 | 39.67 | |||
| Panyptila sanctiheironymi | scotopic | 1 | 5.41 | 13.05 | 6.13 | 2.02 | 1.45 | 34.18 | |||
| Uropsalis segmentata | scotopic | 1 | 4.71 | 13.96 | 10.75 | 3.28 | 3.05 | 10.75 | 11.85 | 22.16 | |
| Eurostopodus macrotis | scotopic | 1 | 11.98 | 20.42 | 13.99 | 5.58 | 4.42 | 13.99 | 18.41 | 27.71 | |
| Hydropsalis climacocerca | scotopic | 1 | 5.72 | 11.91 | 7.77 | 2.97 | 2.35 | 7.77 | 9.58 | 20.02 | |
| Nyctidromus albicollis* | scotopic | 1 | 5.56 | 14.96 | 10.68 | 3.71 | 3.14 | 10.68 | 12.25 | 25.86 | |
| Scotornis climacurus | scotopic | 1 | 6.45 | 12.80 | . | 2.94 | 0.00 | 12.36 | 20.09 | ||
| Podager nacunda* | scotopic | 1 | 9.35 | 18.84 | 12.20 | 4.99 | 3.73 | 12.20 | 14.64 | 27.63 | |
| Nyctiphyrnus ocellatus | scotopic | 1 | 6.23 | 14.80 | 8.54 | 3.64 | 2.93 | 8.54 | 10.33 | 23.17 | |
| Falconiformes | |||||||||||
| Falco sparverius* | photopic | 1 | 3 | 9.11 | 15.42 | 8.20 | 5.18 | 1.68 | 8.20 | 11.98 | 35.85 |
| Ictina plumbea | photopic | 1 | 13.84 | 18.87 | 9.08 | 6.64 | 4.79 | 9.08 | 16.81 | 37.14 | |
| Polyborus plancus | photopic | 3 | 18.28 | 26.90 | 10.00 | 4.34 | 1.30 | 37.14 | |||
| Falco columbarius | photopic | 3 | 16.62 | 16.28 | 9.78 | 2.46 | 44.74 | ||||
| Falco mexicanus | photopic | 1 | 21.69 | 25.20 | 13.84 | 5.29 | 3.54 | 70.45 | |||
| Falco ruficolus | photopic | 2 | 22.39 | 27.01 | 22.59 | 6.19 | 82.31 | ||||
| Micrastur glivicollis* | photopic | 1 | 18.16 | 20.12 | 11.26 | 4.75 | 3.26 | 54.75 | |||
| Micrastur semitorquatus | photopic | 1 | 22.25 | 27.66 | 13.52 | 5.40 | 3.18 | 70.56 | |||
| Microheriax caerulescens* | photopic | 2 | 9.34 | 11.77 | 5.84 | 2.14 | 1.23 | 29.94 | |||
| Sagittarius serpentarius* | photopic | 1 | 27.46 | 35.52 | 12.60 | 5.84 | 66.36 | ||||
| Accipidrae | |||||||||||
| Accipiter francesi | photopic | 1 | 11.26 | 17.75 | 9.76 | 7.93 | 6.94 | 9.76 | 15.08 | 32.58 | |
| Buteo buteo* | photopic | 2 | 17.77 | 23.24 | 14.71 | 7.63 | 50.55 | ||||
| Buteo jamaicensis* | photopic | 2 | 19.83 | 29.71 | 16.11 | 9.60 | 55.87 | ||||
| Aquila chrysaetos* | photopic | 1 | 24.89 | 38.01 | 19.77 | 9.67 | 68.18 | ||||
| Accipiter cooperi* | photopic | 2 | 11.76 | 21.80 | 10.99 | 4.73 | 40.61 | ||||
| Apodiformes | |||||||||||
| Collocalia fuciphaga | photopic | 2 | 4.14 | 10.11 | 6.05 | 4.71 | 4.38 | 4.69 | 8.68 | 24.06 | |
| Collocalia esculenta* | photopic | 3 | 4.09 | 7.14 | 4.37 | 2.73 | 2.24 | 3.91 | 5.92 | 20.43 | |
| Collocalia brevirostris | photopic | 1 | 4.38 | 9.55 | 4.55 | 2.68 | 4.55 | 7.17 | 14.88 | ||
| Apus apus* | photopic | 2 | 6.45 | 11.93 | 6.54 | 3.64 | 2.49 | 5.05 | 9.96 | 30.48 | |
| Apus barbatus* | photopic | 1 | 5.98 | 11.99 | 6.40 | 4.35 | 3.39 | 6.40 | 10.00 | 21.33 | |
| Cypsiurius parvus* | photopic | 3 | 4.29 | 9.12 | 5.25 | 4.89 | 2.66 | 4.64 | 7.59 | 21.16 | |
| Cypseloides rutilus | photopic | 1 | 5.53 | 10.84 | 5.08 | 3.97 | 2.95 | 5.08 | 8.34 | 16.15 | |
| Cypseloides phelpsi | photopic | 1 | 1 | 5.84 | 11.40 | 5.18 | 4.48 | 3.69 | 5.18 | 8.26 | 19.25 |
| Thalurania glaucopis | photopic | 1 | 3.70 | 5.68 | 2.65 | 1.41 | 0.69 | 2.65 | 3.37 | 11.34 | |
| Chaetura brachyura* | photopic | 1 | 5.62 | 10.21 | 4.78 | 4.29 | 3.03 | 4.78 | 7.02 | 17.69 | |
| Chaetura cinereiventris | photopic | 1 | 2.34 | 6.19 | 4.01 | 1.75 | 1.50 | 21.51 | |||
| Chaetura pelagica | photopic | 1 | 7.01 | 10.84 | 4.43 | 2.25 | 1.61 | 26.79 | |||
| Campylopterus duidae | photopic | 1 | 4.36 | 6.37 | 1.92 | 1.92 | 1.29 | 2.82 | 4.56 | 13.27 | |
| Heledoya branickii | photopic | 1 | 3.07 | 6.13 | 3.08 | 1.12 | 0.00 | 3.08 | 4.45 | 11.48 | |
| Telacanthura ussheri | photopic | 1 | 5.44 | 10.11 | 5.79 | 3.35 | 2.52 | 5.79 | 8.44 | 20.83 | |
| Psittaciformes | |||||||||||
| Pionus menstruus* | photopic | 1 | 1 | 11.79 | 15.98 | 7.57 | 4.40 | 1.10 | 7.52 | 10.57 | 46.12 |
| Deroptyus accipitrinus* | photopic | 1 | 13.84 | 17.10 | 7.22 | 5.15 | 2.59 | 7.22 | 13.34 | 47.51 | |
| Poicephalus senagalus* | photopic | 1 | 8.85 | 13.96 | 6.65 | 3.91 | 2.71 | 6.65 | 10.90 | 38.02 | |
| Pyrrhyra rhodogaster | photopic | 1 | 7.05 | 12.09 | 5.55 | 2.64 | 0.60 | 5.55 | 7.98 | 33.84 | |
| Polytelis alexandriae* | photopic | 1 | 7.09 | 12.64 | 5.44 | 3.02 | 1.41 | 5.44 | 7.74 | 31.78 | |
| Rychpsutta pachyryncha | photopic | 1 | 10.50 | 14.28 | 7.68 | 3.72 | 2.45 | 7.68 | 9.57 | 51.09 | |
| Aratinga weddellii | photopic | 1 | 6.74 | 12.92 | 6.08 | 3.54 | 2.17 | 6.08 | 8.59 | 33.36 | |
| Chalcopsitta atra | photopic | 1 | 7.32 | 13.70 | 6.23 | 3.79 | 2.27 | 6.23 | 10.26 | 41.87 | |
| Loriculus galgulus | photopic | 1 | 6.13 | 9.31 | 4.40 | 0.78 | 0.00 | 29.49 | |||
| Psittacus erithacus timni | photopic | 1 | 11.11 | 16.72 | 7.88 | 0.95 | 0.00 | 57.94 | |||
| Poicephalus senegalus* | photopic | 1 | 9.67 | 14.47 | 6.17 | 1.53 | 0.00 | 46.00 | |||
| Psittacuse erithacus | photopic | 1 | 12.43 | 18.34 | 7.48 | 1.72 | 0.00 | 65.66 | |||
| Poicephalus cryptoxanthus | photopic | 1 | 6.64 | 14.74 | 6.19 | 1.49 | 0.00 | 43.57 | |||
| Agapornis canus* | photopic | 1 | 4.70 | 8.31 | 3.32 | 0.77 | 0.00 | 29.00 | |||
| Loriculus philippensis | photopic | 1 | 6.11 | 9.54 | 4.86 | 0.58 | 0.00 | 32.48 | |||
| Psittacula alexandri fasciata | photopic | 1 | 9.03 | 13.13 | 6.15 | 1.47 | 0.00 | 47.40 | |||
| Agapornis nigrensis | photopic | 1 | 5.60 | 8.13 | 3.64 | 0.67 | 0.00 | 30.98 | |||
| Agapornis personata | photopic | 1 | 5.12 | 10.65 | 4.65 | 1.06 | 0.00 | 33.45 | |||
| Agapornis roseicollis | photopic | 1 | 5.74 | 9.94 | 4.80 | 0.68 | 0.00 | 33.53 | |||
| Psittacula krameri* | photopic | 1 | 8.18 | 13.76 | 5.95 | 0.74 | 0.00 | 40.84 | |||
| Psittacula roseata | photopic | 1 | 7.67 | 9.91 | 5.26 | 0.59 | 0.00 | 36.12 | |||
| Agapornis taranta | photopic | 1 | 6.30 | 10.54 | 4.27 | 1.08 | 0.00 | 34.74 | |||
| Anodorynchus glaucus | photopic | 1 | 16.08 | 23.20 | 9.17 | 1.78 | 0.00 | 85.56 | |||
| Graydidascalus brachyurus | photopic | 1 | 11.34 | 13.34 | 7.20 | 1.35 | 0.00 | 99.12 | |||
| Pionus sordidus | photopic | 1 | 12.53 | 14.89 | 6.65 | 1.71 | 0.00 | 50.12 | |||
| Pionites leucogaster | photopic | 1 | 12.38 | 14.07 | 7.19 | 1.72 | 0.00 | 50.38 | |||
| Aratinga erythrogenys | photopic | 1 | 13.05 | 14.76 | 7.00 | 0.88 | 0.00 | 48.43 | |||
| Nondayus nenday | photopic | 1 | 9.16 | 12.56 | 6.14 | 0.96 | 0.00 | 46.70 | |||
| Bolborynchus aurifrons | photopic | 1 | 5.54 | 8.76 | 4.32 | 0.69 | 0.00 | 29.79 | |||
| Aratinga leucopthalmus* | photopic | 1 | 11.38 | 14.44 | 6.45 | 1.19 | 0.00 | 51.39 | |||
| Myopsitta monachus | photopic | 1 | 7.91 | 10.96 | 4.94 | 1.14 | 0.00 | 38.09 | |||
| Pezoporus wallicus* | scotopic | 1 | 7.94 | 13.33 | 6.85 | 2.47 | 2.05 | 26.89 | |||
| Columbiformes | |||||||||||
| Turtur afer* | photopic | 1 | 6.47 | 12.84 | 5.01 | 3.47 | 2.06 | 5.01 | 8.28 | 23.46 | |
| Gallicolumba luzonica* | photopic | 1 | 7.54 | 14.32 | 6.22 | 3.20 | 0.00 | 6.22 | 7.30 | 28.75 | |
| Lepitola verreauxi* | photopic | 1 | 9.82 | 14.62 | 5.98 | 4.61 | 2.92 | 5.98 | 9.84 | 32.01 | |
| Geotrygon montana* | photopic | 1 | 6.41 | 12.65 | 5.69 | 3.25 | 5.69 | 8.87 | 26.01 | ||
| Treron vernans | photopic | 1 | 8.14 | 13.73 | 5.76 | 3.59 | 2.43 | 5.76 | 8.33 | 28.98 | |
| Chalcops indica | photopic | 1 | 2 | 7.99 | 13.53 | 6.23 | 3.29 | 1.18 | 6.23 | 8.87 | 25.66 |
| Streptopelia chinensis | photopic | 1 | 6.77 | 13.74 | 5.35 | 3.65 | 1.96 | 5.35 | 8.83 | 24.82 | |
| Pterocles cornata | photopic | 1 | 6.28 | 13.85 | 6.73 | 4.03 | 2.67 | 6.73 | 10.46 | 29.61 | |
| Columba plumbea* | photopic | 1 | 7.09 | 13.44 | 6.24 | 3.94 | 2.28 | 6.24 | 9.39 | 30.72 | |
| Streptopelia vinacea* | photopic | 1 | 6.43 | 12.84 | 6.07 | 2.01 | 0.92 | 26.48 | |||
| Leucosarcia melanoleuca | photopic | 1 | 10.73 | 16.26 | 7.95 | 2.71 | 1.68 | 32.04 | |||
| Zenaiela asiatica | photopic | 1 | 6.79 | 13.64 | 6.97 | 2.39 | 1.35 | 29.70 | |||
| Ptilinopus aurantiif | photopic | 1 | 8.51 | 13.66 | 6.90 | 1.93 | 0.55 | 30.24 | |||
| Zenaida macroura | photopic | 1 | 5.40 | 13.30 | 6.55 | 2.03 | 1.28 | 26.91 | |||
| Petrophassa plumifer | photopic | 1 | 5.92 | 12.43 | 5.16 | 2.12 | 1.28 | 23.98 | |||
| Ocyphaps lophotes | photopic | 1 | 8.11 | 14.39 | 6.44 | 2.08 | 1.32 | 28.71 | |||
| Goura victoria | photopic | 1 | 13.19 | 23.76 | 10.68 | 4.62 | 3.24 | 47.55 | |||
| Struthioniformes | |||||||||||
| Struthio camellus | photopic | 1 | 2 | 39.30 | 47.19 | 26.41 | 8.15 | 6.17 | 11.53 | 38.00 | 94.40 |
| Casuariiformes | |||||||||||
| Casuariius sp.* | photopic | 1 | 31.60 | 19.61 | 7.28 | 120.12 | |||||
| Tinamiformes | |||||||||||
| Eudromia elegans | photopic | 1 | 6.24 | 16.77 | 8.25 | 3.75 | 2.60 | 33.25 | |||
| Nothoprocta ornata* | photopic | 1 | 7.68 | 14.35 | 7.25 | 3.13 | 1.78 | 29.93 | |||
| Crypturellus tataupa | photopic | 1 | 7.10 | 12.19 | 5.27 | 2.59 | 0.81 | 24.90 | |||
| Crypturellus noctivagus | photopic | 1 | 9.94 | 17.57 | 9.25 | 3.89 | 3.09 | 34.70 | |||
| Charadriiformes | |||||||||||
| Scolopax minor | photopic | 2 | 7.95 | 14.20 | 9.03 | 2.36 | 1.41 | 27.09 | |||
| Scolopax rusticola | scotopic | 2 | 10.27 | 16.39 | 9.80 | 2.38 | 1.38 | 29.43 | |||
| Gallinago gallinago | scotopic | 2 | 4.89 | 10.84 | 5.99 | 1.52 | 1.26 | 22.71 | |||
| Vanellus tricolor* | photopic | 2 | 8.75 | 16.88 | 7.95 | 3.22 | 2.30 | 29.15 | |||
| Pluvalis dominica | photopic | 3 | 5.73 | 16.41 | 8.49 | 2.51 | 2.55 | 28.07 | |||
| Numenius phaeopus hudsonicus | photopic | 2 | 6.71 | 16.79 | 7.45 | 3.40 | 1.95 | 34.94 | |||
| Charadrius melodus | photopic | 1 | 5.28 | 12.30 | 6.66 | 2.31 | 1.84 | 21.66 | |||
| Charadrius vociferus* | photopic | 3 | 6.54 | 14.36 | 7.47 | 2.27 | 1.80 | 25.15 | |||
| Burhinus oedicnemus | scotopic | 1 | 8.91 | 22.38 | 12.81 | 4.96 | 3.80 | 38.38 | |||
| Burhinus bistratus* | scotopic | 1 | 19.26 | 27.15 | 15.95 | 5.35 | 4.50 | 45.94 | |||
| Burhinus capensis | scotopic | 1 | 16.43 | 25.67 | 15.28 | 4.65 | 3.67 | 41.19 | |||
| Burhinus magnirostris | scotopic | 2 | 17.08 | 26.46 | 16.27 | 4.56 | 4.88 | 46.39 | |||
| Haematops palliatus* | photopic | 1 | 8.99 | 19.02 | 9.81 | 3.52 | 3.02 | 33.55 | |||
*
Included in the phylogeny for phylogenetic independent contrasts.
Raw data for eye dimensions and related hard-tissue variables. All birds were coded for activity pattern from the literature as follows: (1) König et al. (1999) and del Hoyo et al. (2000); (2) Cleere & Nurney (1998); (3) Ferguson-Lees & Christie (2001); (4) Chantler & Driessens (1995); (5) Juniper & Parr (1998); (6) del Hoyo et al. (1997); (7) del Hoyo et al. (1992); (8) del Hoyo et al. (1996). For axial sclerotic ring length measurements, if the cell is blank, the measurement is not present; if ‘0’ is indicated, the sclerotic ring is flat and therefore no length can be calculated.