Fig. 1.

The presence/absence patterns of avian opsins. Green circles indicate the presence of a complete gene sequence; yellow circles represent a partial gene sequence; red cross indicates that no sequences were found by t-blastn searches. For the visual opsins, the species highlighted with a yellow line have a tetrachromatic visual system. The bird phylogeny and the mean divergence times were based on Jarvis et. al (2014) [17]. The high coverage genomes (≥80X) are indicated in bold. Numbers identify each species: 1. Merops nubicus, 2. Picoides pubescens, 3. Buceros rhinoceros, 4. Apaloderma vittatum, 5. Leptosomus discolor, 6. Colius striatus, 7. Tyto alba, 8. Haliaeetus leucocephalus, 9. Haliaeetus albicilla, 10. Cathartes aura, 11. Taeniopygia guttata, 12. Geospiza fortis, 13. Corvus brachyrhynchos, 14. Manacus vitellinus, 15. Acanthisitta chloris, 16. Nestor notabilis, 17. Melopsittacus undulatus, 18. Falco peregrinus, 19. Cariama cristata, 20. Pelecanus crispus, 21. Egretta garzetta, 22. Nipponia nippon, 23. Phalacrocorax carbo, 24. Aptenodytes forsteri, 25. Pygoscelis adeliae, 26. Fulmarus glacialis, 27. Gavia stellata, 28. Eurypyga helias, 29. Phaethon lepturus, 30. Balearica regulorum, 31. Charadrius vociferus, 32. Opisthocomus hoazin, 33. Calypte anna, 34. Chaetura pelagica, 35. Antrostomus carolinensis, 36. Chlamydotis macqueenii, 37. Tauraco erythrolophus, 38. Cuculus canorus, 39. Mesitornis unicolor, 40. Pterocles gutturalis, 41. Columba livia, 42. Podiceps cristatus, 43. Phoenicopterus ruber, 44. Meleagris gallopavo, 45. Gallus gallus, 46. Anas platyrhynchos, 47. Struthio camelus and 48. Tinamus major