1500-800 BC - The Vedas mention the habit of brood parasitism in the Koel (Eudynamys scolopacea). [Ali, S. (1979), Bird study in India : its history and its importance. ICCR, New Delhi. Azad Memorial Lectures.]
4th century BC - Aristotle mentions over 170 sorts of birds in his work on animals. He recognises eight principal groups
2nd century - Aelian mentions a number of birds in his work on animals. Birds are listed alphabetically
1478 - De Avibus by Albertus Magnus is printed, which mentions many bird names for the first time
1485 - First dated copy of Ortus sanitatis by Johannes de Cuba
1544 - William Turner prints a commentary of the birds mentioned by Aristotle and Pliny
1555 - Conrad Gessner's Historic Animalium qui est de Auium natura and Pierre Belon's (Bellonius) Histoire de la nature des Oyseaux. Belon lists birds according to a definite system
1573 - Volcher Coiter publishes his first treatise on bird anatomy
1676 - Publication of Francis Willughby's Ornithologia by his collaborator John Ray. This is considered the beginning of scientific ornithology in Europe, revolutionizing ornithological taxonomy by organizing species according to their physical characteristics
1731-1743 - Mark Catesby publishes his Natural History of Carolina, which contains coloured plates of the birds of that colony, Florida and the Bahamas
1735 - First edition of Carolus Linnaeus' Systema Naturae. The classification of birds follows that of Ray
1788 - Johann Friedrich Gmelin commences work on the 13th edition of Systema Naturae which includes the classification of many birds for the first time, especially those described by Latham
1789 - Publication of Gilbert White's Natural History and Antiquities of Selborne
1797 - François Le Vaillant begins publication of his Oiseaux d'Afrique giving details of species encountered on his exploration of South Africa
1889 - Ludwig Koch makes the first sound recording of birdsong, that of a captive Common Sharma
1899 - Christian Mortensen of Viborg, Denmark is the first ornithologist to undertake systematic large-scale ringing. He uses numbered aluminium rings to mark 165 Starlings caught in nestboxes
20th Century
1901 - Johannes Thienemann establishes "Vogelwarte Rossitten" (now Rybachy ), the world's first bird observatory
1909 - A bird observatory is established at Heligoland by Hugo Weigold . Birds are collected in specially designed wire-netting traps, still known today as "Heligoland traps"
1922 - Foundation of the International Council for Bird Preservation (now Birdlife International )
1922 - Publication of John Charles Phillips's A Natural History of the Ducks, which provides maps of the known breeding and wintering distributions of ducks throughout the world
1928 - Ernst Mayr leads the first of three expeditions to New Guinea and the Solomon Islands, during which he discovers many new species
1967 - Publication of Radar Ornithology by Eric Eastwood
1968-1972 - First national breeding bird atlas project conducted in Britain and Ireland
1970 - The Atlas of Breeding Birds of the West Midlands by Lord and Munns, based on field work by members of the West Midland Bird Club, published by Collins, is the first to use systematic grid-based method for gathering of information.
1976 - Publication of national atlases for Great Britain and Ireland, France and Denmark
1981 - Sibley and Ahlquist use DNA-DNA hybridisation to determine degrees of genetic similarity between species
1984 - Publication of The Atlas of Australian Birds
1989 - Discovery of the first poisonous bird, the Hooded PitohuiPitouhi dichrous and Homobatrachotoxin by Jack Dumbacher
1991 - First new species described without a type specimen. The Bulo Burti boubou shrike (Laniarius liberatus) of Somalia described as a new species on the basis of the DNA sequence from a feather.
1997 - Use of stable Hydrogen isotope signatures in feathers to identify origin of birds. [Chamberlain CP, Blum JD, Holmes RT, Feng X, Sherry TW,Graves GR (1997) The use of isotope tracers for identifyingpopulations of migratory birds. Oecologia 109:132–141]
1998 - Discovery of gut reduction before migration in Godwits. [Piersma T, Gill RE (1998) Guts don't fly: small digestive organs in obese bar-tailed godwits. Auk 115:196–203]