The following constitutes a timeline of ornithology events:

BC up

• 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
• 1st century - Pliny the Elder's Historia Naturalis Book X is devoted to birds. Three groups based on feet characteristics
• 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
• 1681 - The last Dodo dies on the island of Mauritius

18th Century

• 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
• 1741 - Georg Steller studies the birds of the north Pacific on his voyage with Vitus Bering
• 1743 - George Edwards begins publication of his bird plates
• 1760 - Mathurin Jacques Brisson's six-volume Ornithologie improves upon Linnaeus' classification
• 1768-1780 - Voyages of James Cook to the Pacific and Australia during which many birds new to science are collected by Joseph Banks and Johann Reinhold Forster
• 1770-1783 - Buffon's Histoire Naturelle des Oiseaux was the first work to take into account the geographical distribution of birds
• 1776 - Francesco Cetti publishes Uccelli di Sardegna
• 1778 - Juan Ignacio Molina publishes Saggio sulla storia naturale del Chile which includes the first descriptions of many South American species
• 1785 - John Latham completes his Synopsis of Birds, which describes many birds collected in Australia and the Pacific Ocean. Thomas Pennant publishes Arctic Zoology.
• 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
• 1797 -1804 - Publication of Thomas Bewick's British Birds

19th Century

• 1801 - Alexander Wilson begins his study of North American birds, resulting in his American Ornithology (1808-1814), later updated by Charles Lucien Bonaparte
• 1802 - Publication of George Montagu's Ornithological Dictionary
• 1811 - Publication of Peter Simon Pallas' Zoographia Russo-Asiatica includes details of the birds encountered in his journeys through Siberia
• 1815 - Coenraad Jacob Temminck publishes his Manuel d'ornithologie, the standard work on European birds for many years
• 1827-1838 - Publication of John James Audubon's Birds of America
• 1831-1836 - Charles Darwin travels to South America and the Galapagos Islands on board HMS Beagle. His study of Galapagos finches gives him ideas on natural selection
• 1832 - Edward Lear publishes Illustrations of the Family of Psittacidae
• 1838 - John Gould travels to Australia with his wife to study the birds of that country
• 1840 - John Gould publishes the first part of his Birds of Australia
• 1844 - The last Great Auk is recorded in Iceland
• 1857 - Philip Sclater presents his paper On the General Geographical Distribution of the Members of the Class Aves to the Linnean Society
• 1858 - Alfred Newton forms the British Ornithologists' Union
• 1861 - Fossil of archaeopteryx found in Germany supports link between dinosaurs and birds
• 1868 - Association for the Protection of Seabirds formed in England
• 1869 - The Seabirds Protection Act is the first law passed in the United Kingdom to protect birds
• 1873 - Publication of Ornitologia Italiana by Paolo Savi
• 1879 - Richard Owen publishes the results of his studies of Moa fossils
• 1883 - Foundation of the American Ornithologists' Union
• 1883 - Foundation of the Bombay Natural History Society
• 1884 - First International Ornithological Congress held in Vienna, with Gustav Radde as President
• 1889 - Foundation of the Royal Society for the Protection of Birds to campaign against the plumage trade
• 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
• 1901 - The Royal Australasian Ornithologists Union established
• 1905 - Foundation of the National Audubon Society
• 1907 - The monthly journal British Birds begins publication
• 1909 - First organised ringing schemes in the UK
• 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"
• 1909 - First known mapping census carried out in Kent, England by the Alexander brothers
• 1910-1911 - BOU expedition to Dutch New Guinea
• 1912 - A Barn Swallow ringed by James Masefield in Staffordshire, England is recovered in Natal, South Africa
• 1914 - The last Passenger Pigeon dies in Cincinnati Zoo
• 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
• 1930 - Alexander Wetmore publishes his Systematic Classification
• 1931 - Ernst Schüz and Hugo Weigold publish Atlas des Vogelzuges, the first atlas of bird migration
• 1932 - Foundation of the British Trust for Ornithology for the study of birds in Britain
• 1934 - Roger Tory Peterson publishes his Guide to the Birds, the first modern field guide
• 1935 - Konrad Lorenz publishes his study of imprinting in young ducklings and goslings
• 1937 - Margaret Morse Nice publishes Studies in the Life History of the Song Sparrow
• 1938 - Foundation of the Edward Grey Institute of Field Ornithology
• 1943 - David Lack makes calculations of bird mortality using reports of ringed birds
• 1946 - Peter Scott founds the Wildfowl and Wetlands Trust at Slimbridge

20th Century late

• 1950 - Rocket nets developed by the Wildfowl Trust for catching geese
• 1951-1954 - The 6-volume Birds of the Soviet Union by GP Dementev and NA Gladkov published
• 1953 - Niko Tinbergen publishes The Herring Gull's World
• 1954 - Protection of Birds Act in the UK prohibits the collection of birds eggs
• 1956 - First use of mist nets (invented in Japan) in the UK to trap birds
• 1962 - Rachel Carson publishes Silent Spring, describing the ecological dangers of pesticides
• 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 Pitohui Pitouhi 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]

21st Century