Editing Ornithology (section)

===Scientific studies===
[[File:Bird eggs.jpg|thumb|left|Early bird study focused on collectibles such as eggs and nests.]]
The emergence of ornithology as a scientific discipline began in the 18th century, when [[Mark Catesby]] published his two-volume ''Natural History of Carolina, Florida, and the Bahama Islands'', a landmark work which included 220 hand-painted engravings and was the basis for many of the species [[Carl Linnaeus]] described in the 1758 ''[[10th edition of Systema Naturae|Systema Naturae]]''. Linnaeus' work revolutionised bird taxonomy by assigning every species a [[binomial nomenclature|binomial name]], categorising them into different genera. However, ornithology did not emerge as a specialised science until the Victorian era—with the popularization of natural history, and the collection of natural objects such as bird eggs and skins.<ref name="allen">{{cite book|author=Allen, David E.|year=1994|title=The naturalist in Britain: a social history|isbn=978-0691036328|publisher=Princeton University Press}}</ref><ref>{{cite book|author=Farber, Paul L.|year=1982|title=The Emergence of Ornithology as a Scientific Discipline, 1760–1850|publisher=D. Reidel Publishing Company, Boston}}</ref> This specialization led to the formation in Britain of the [[British Ornithologists' Union]] in 1858. In 1859, the members founded its journal ''[[The Ibis]]''. The sudden spurt in ornithology was also due in part to [[colonialism]]. At 100 years later, in 1959, [[Reginald Ernest Moreau|R. E. Moreau]] noted that ornithology in this period was preoccupied with the geographical distributions of various species of birds.<ref name="ibis-history">{{cite journal|author=Johnson, Kristin|year=2004|title=''The Ibis'': Transformations in a Twentieth Century British Natural History Journal|journal=Journal of the History of Biology|volume=37|pages=515–555| doi=10.1007/s10739-004-1499-3|issue=3|s2cid=83849594}}</ref>
{{Quote|No doubt the preoccupation with widely extended geographical ornithology, was fostered by the immensity of the areas over which British rule or influence stretched during the 19th century and for some time afterwards.|Moreau<ref>{{cite journal|author=Moreau, R. E.|year=1959|title=The Centenarian Ibis|journal=The Ibis|volume=101|pages=19–38|doi=10.1111/j.1474-919X.1959.tb02353.x}}</ref>}}

The bird collectors of the Victorian era observed the variations in bird forms and habits across geographic regions, noting local specialization and variation in widespread species. The collections of museums and private collectors grew with contributions from various parts of the world. The naming of species with binomials and the organization of birds into groups based on their similarities became the main work of museum specialists. The variations in widespread birds across geographical regions caused the introduction of trinomial names.
[[File:KaupClassification.svg|thumb|Kaup's classification of the crow family]]
The search for patterns in the variations of birds was attempted by many. [[Friedrich Wilhelm Joseph Schelling]] (1775–1854), his student [[Johann Baptist von Spix]] (1781–1826), and several others believed that a hidden and innate mathematical order existed in the forms of birds. They believed that a "natural" classification was available and superior to "artificial" ones. A particularly popular idea was the [[Quinarian system]] popularised by [[Nicholas Aylward Vigors]] (1785–1840), [[William Sharp Macleay]] (1792–1865), [[William Swainson]], and others. The idea was that nature followed a "rule of five" with five groups nested hierarchically. Some had attempted a rule of four, but [[Johann Jakob Kaup]] (1803–1873) insisted that the number five was special, noting that other natural entities such as the senses also came in fives. He followed this idea and demonstrated his view of the order within the crow family. Where he failed to find five genera, he left a blank insisting that a new genus would be found to fill these gaps. These ideas were replaced by more complex "maps" of affinities in works by [[Hugh Edwin Strickland]] and [[Alfred Russel Wallace]].<ref name=ohara>{{cite journal|author=O’Hara, Robert J.|year=1988|title=Diagrammatic classifications of birds, 1819–1901: views of the natural system in 19th-century British ornithology|pages=2746–2759 |journal=Acta XIX Congressus Internationalis Ornithologici|url=http://rjohara.net/cv/1988-ioc}}</ref><ref>{{Cite book|year=1975|isbn=978-0-674-64485-4|author=Stresemann, Erwin|title=Ornithology. From Aristotle to the Present|publisher=Harvard University Press|place=Cambridge, Massachusetts|pages=170–191}}</ref> A major advance was made by [[Max Fürbringer]] in 1888, who established a comprehensive phylogeny of birds based on anatomy, morphology, distribution, and biology. This was developed further by [[Hans Gadow]] and others.<ref>{{cite book|author=Fürbringer, Max |year=1888| title= Untersuchungen zur morphologie und systematik der vogel. Volume II. |place=Amsterdam| publisher= Verlag von TJ. Van Holkema|url= https://www.biodiversitylibrary.org/bibliography/51998| language=de}}</ref><ref>{{cite journal| author=Stresemann, E. |year=1959| title=The status of avian systematics and its unsolved problems| journal=Auk| volume=76|issue=3| pages=269–280| url=https://sora.unm.edu/sites/default/files/journals/auk/v076n03/p0269-p0280a.pdf |archive-url=https://ghostarchive.org/archive/20221009/https://sora.unm.edu/sites/default/files/journals/auk/v076n03/p0269-p0280a.pdf |archive-date=2022-10-09 |url-status=live| doi=10.2307/4081807|jstor=4081807}}</ref>

The [[Galapagos]] [[finch]]es were especially influential in the development of [[Charles Darwin]]'s theory of evolution. His contemporary [[Alfred Russel Wallace]] also noted these variations and the geographical separations between different forms leading to the study of [[biogeography]]. Wallace was influenced by the work of [[Philip Lutley Sclater]] on the distribution patterns of birds.<ref>{{cite journal|author=Sclater, P. L.|year=1858|title=On the general geographical distribution of the members of the class Aves|doi=10.1111/j.1096-3642.1858.tb02549.x|journal=Proc. Linn. Soc. Lond.|volume=9|pages=130–136|issue=7}}</ref>
[[File:SwainsonQuinarian.jpg|thumb|right|[[Quinarian system]] of bird classification by Swainson]]
For Darwin, the problem was how species arose from a common ancestor, but he did not attempt to find rules for delineation of species. The [[species problem]] was tackled by the ornithologist [[Ernst Mayr]], who was able to demonstrate that geographical isolation and the accumulation of genetic differences led to the [[Allopatric speciation|splitting of species]].<ref name=konishi>{{cite journal|author1=Konishi, Masakazu |author2=Emlen, Stephen T. |author3=Ricklefs, Robert E. |author4=Wingfield, John C.  |name-list-style=amp |year=1989|title=Contributions of Bird Studies to Biology|journal=Science|volume=246|issue=4929|pages=465–472|doi=10.1126/science.2683069|pmid=2683069|bibcode = 1989Sci...246..465K }}</ref><ref>{{cite journal|title=Ornithology and the genesis of the Synthetic Theory of Evolution|last=Junker|first=Thomas|journal=Avian Science|volume=3|issue=2&3|pages=65–73|year=2003|url=http://www.thomas-junker.homepage.t-online.de/pdf/03tjas.pdf |archive-url=https://ghostarchive.org/archive/20221009/http://www.thomas-junker.homepage.t-online.de/pdf/03tjas.pdf |archive-date=2022-10-09 |url-status=live}}</ref>

Early ornithologists were preoccupied with matters of species identification. Only systematics counted as true science and field studies were considered inferior through much of the 19th century.<ref name=haffer/> In 1901, [[Robert Ridgway]] wrote in the introduction to ''The Birds of North and Middle America'' that:
{{Quote|There are two essentially different kinds of ornithology: systematic or scientific, and popular. The former deals with the structure and classification of birds, their synonymies, and technical descriptions. The latter treats of their habits, songs, nesting, and other facts pertaining to their life histories.}}
This early idea that the study of living birds was merely recreation held sway until ecological theories became the predominant focus of ornithological studies.<ref name=mayr/><ref name="ibis-history"/> The study of birds in their habitats was particularly advanced in Germany with [[bird ringing]] stations established as early as 1903. By the 1920s, the ''[[Journal für Ornithologie]]'' included many papers on the behaviour, ecology, anatomy, and physiology, many written by [[Erwin Stresemann]]. Stresemann changed the editorial policy of the journal, leading both to a unification of field and laboratory studies and a shift of research from museums to universities.<ref name=haffer>{{cite journal|journal=Archives of Natural History|volume=35|issue=1|pages=76–87|year=2008|title=The origin of modern ornithology in Europe|last=Haffer|first= Jürgen|author-link=Jürgen Haffer|doi=10.3366/E0260954108000077}}</ref> Ornithology in the United States continued to be dominated by museum studies of morphological variations, species identities, and geographic distributions, until it was influenced by Stresemann's student [[Ernst Mayr]].<ref name="barrow">{{cite book|author=Barrow, Mark V.|year=1998|title=A passion for birds: American ornithology after Audubon|publisher=Princeton University Press|isbn=978-0691049540}}</ref> In Britain, some of the earliest ornithological works that used the word ecology appeared in 1915.<ref>{{cite journal|author=Alexander, H. G.|year=1915|title=A Practical Study of Bird Ecology|journal=British Birds|volume=8|issue=9}}</ref> ''The Ibis'', however, resisted the introduction of these new methods of study, and no paper on ecology appeared until 1943.<ref name="ibis-history"/> The work of [[David Lack]] on population ecology was pioneering. Newer quantitative approaches were introduced for the study of ecology and behaviour, and this was not readily accepted. For instance, [[Claud Ticehurst]] wrote:
{{Quote|Sometimes it seems that elaborate plans and statistics are made to prove what is commonplace knowledge to the mere collector, such as that hunting parties often travel more or less in circles.|Ticehurst<ref name="ibis-history"/>}}
David Lack's studies on population ecology sought to find the processes involved in the regulation of population based on the evolution of optimal clutch sizes. He concluded that population was regulated primarily by [[Density-dependent inhibition|density-dependent controls]], and also suggested that natural selection produces life-history traits that maximize the fitness of individuals. Others, such as [[V. C. Wynne-Edwards|Wynne-Edwards]], interpreted population regulation as a mechanism that aided the [[Group selection|"species" rather than individuals]]. This led to widespread and sometimes bitter debate on what constituted the "unit of selection".<ref name=konishi/> Lack also pioneered the use of many new tools for ornithological research, including the idea of using [[Radar ornithology|radar]] to study bird migration.<ref>{{cite journal|author=Lack, David|year=1959|title=Watching migration by Radar|url=https://www.britishbirds.co.uk/wp-content/uploads/article_files/V52/V52_N08/V52_N08_P258_267_A056.pdf |archive-url=https://ghostarchive.org/archive/20221009/https://www.britishbirds.co.uk/wp-content/uploads/article_files/V52/V52_N08/V52_N08_P258_267_A056.pdf |archive-date=2022-10-09 |url-status=live|journal=British Birds|volume=52|issue=8|pages=258–267}}</ref>

Birds were also widely used in studies of the niche hypothesis and [[Georgii Gause]]'s [[competitive exclusion]] principle. Work on resource partitioning and the structuring of bird communities through competition were made by [[Robert MacArthur]]. Patterns of [[biodiversity]] also became a topic of interest. Work on the relationship of the number of species to area and its application in the study of [[island biogeography]] was pioneered by [[E. O. Wilson]] and [[Robert MacArthur]].<ref name=konishi/> These studies led to the development of the discipline of [[landscape ecology]].
[[File:Red-footed Falcon.jpeg|thumb|left|A mounted specimen of a [[red-footed falcon]]]]
[[John Crook (ethologist)|John Hurrell Crook]] studied the behaviour of [[weaverbird]]s and demonstrated the links between ecological conditions, behaviour, and social systems.<ref name=konishi/><ref>{{cite journal|author=Crook, J. H.|author-link=John Crook (ethologist)|year=1964|title=The evolution of social organization and visual communication in the weaver birds (Ploceinae)|journal=Behaviour. Supplement|volume=10|pages=1–178}}</ref><ref name=Crook1980>{{Cite book | last=Crook| first=J. H. | title= The Evolution of Human Consciousness |publisher=Clarendon Press| year=1980| location=Oxford | pages=45–49| isbn=978-0-19-857174-2}}</ref> Principles from [[economics]] were introduced to the study of biology by Jerram L. Brown in his work on explaining territorial behaviour. This led to more studies of behaviour that made use of [[cost-benefit analyses]].<ref>{{cite journal|author=Brown, J. L.|year=1964|title=The evolution of diversity in avian territorial systems|journal=Wilson Bull.|volume=76|pages=160–169 |url=http://sora.unm.edu/sites/default/files/journals/wilson/v076n02/p0160-p0169.pdf |archive-url=https://ghostarchive.org/archive/20221009/http://sora.unm.edu/sites/default/files/journals/wilson/v076n02/p0160-p0169.pdf |archive-date=2022-10-09 |url-status=live}}</ref> The rising interest in [[sociobiology]] also led to a spurt of bird studies in this area.<ref name=konishi/><ref>{{cite journal|url=https://sora.unm.edu/node/636|title=Contents |journal = The Auk|date = 1981 |volume = 98 | number= 2|publisher = Searchable Ornithological Research Archive }}</ref>

The study of imprinting behaviour in ducks and geese by [[Konrad Lorenz]] and the studies of instinct in [[European herring gull|herring gull]]s by [[Nicolaas Tinbergen]] led to the establishment of the field of [[ethology]]. The study of learning became an area of interest and the study of [[Birdsong|bird songs]] has been a model for studies in neuroethology. The study of hormones and physiology in the control of behaviour has also been aided by bird models. These have helped in finding the [[Proximate and ultimate causation|proximate causes]] of circadian and seasonal cycles. Studies on migration have attempted to answer questions on the evolution of migration, orientation, and navigation.<ref name=konishi/>

The growth of genetics and the rise of molecular biology led to the application of the [[gene-centered view of evolution]] to explain avian phenomena. Studies on kinship and altruism, such as [[helpers at the nest|helpers]], became of particular interest. The idea of [[inclusive fitness]] was used to interpret observations on behaviour and life history, and birds were widely used models for testing hypotheses based on theories postulated by [[W. D. Hamilton]] and others.<ref name=konishi/>

The new tools of molecular biology changed the study of bird systematics, which changed from being based on [[phenotype]] to the underlying [[genotype]]. The use of techniques such as [[DNA–DNA hybridization]] to study evolutionary relationships was pioneered by [[Charles Sibley]] and [[Jon Edward Ahlquist]], resulting in what is called the [[Sibley–Ahlquist taxonomy]]. These early techniques have been replaced by newer ones based on [[mitochondrial DNA]] sequences and [[molecular phylogenetics]] approaches that make use of computational procedures for [[sequence alignment]], construction of [[phylogenetic tree]]s, and calibration of [[molecular clock]]s to infer evolutionary relationships.<ref>{{cite journal |author=O'Hara, Robert J.|year=1991|title=Essay review of Phylogeny and Classification of Birds: A Study in Molecular Evolution by Charles G. Sibley and Jon E. Ahlquist|journal=Auk|volume=108|issue=4|pages=990–994|url=http://rjohara.net/cv/1991-auk}}</ref><ref>{{cite journal|author=Slack, K.E, Delsuc, F., Mclenachan, P.A., Arnason, U. & D. Penny|year=2007|title=Resolving the root of the avian mitogenomic tree by breaking up long branches|journal=Molecular Phylogenetics and Evolution|volume=42|pmid=16854605|issue=1|pages=1–13|url=http://frederic.delsuc.neuf.fr/fd_fichiers/Slack-MolPhylogenetEvol07.pdf|doi=10.1016/j.ympev.2006.06.002|bibcode=2007MolPE..42....1S |citeseerx=10.1.1.561.5255|s2cid=6683688 |access-date=2007-11-30|archive-url=https://web.archive.org/web/20071130233730/http://frederic.delsuc.neuf.fr/fd_fichiers/Slack-MolPhylogenetEvol07.pdf|archive-date=2007-11-30|url-status=dead}}</ref> Molecular techniques are also widely used in studies of avian [[population biology]] and ecology.<ref>{{cite journal|author=Sorenson, M. D.|year=2002|title=Molecular Genetic Perspectives on Avian Brood Parasitism|journal=Integr. Comp. Biol.|volume=42|pages=388–400|doi=10.1093/icb/42.2.388|issue=2|pmid=21708732|last2=Payne|first2=RB|doi-access=free}}</ref>