Editing Ornithology (section)

===In the laboratory===
Many aspects of bird biology are difficult to study in the field. These include the study of behavioural and physiological changes that require a long duration of access to the bird. Nondestructive samples of blood or feathers taken during field studies may be studied in the laboratory. For instance, the variation in the ratios of stable hydrogen isotopes across latitudes makes establishing the origins of migrant birds possible using [[mass spectrometry|mass spectrometric]] analysis of feather samples.<ref>{{cite journal|author=Hobson, K. A. Hobson, Steven Van Wilgenburg, Leonard I. Wassenaar, Helen Hands, William P. Johnson, Mike O'Meilia & Philip Taylor|year=2006|title=Using Stable Hydrogen Isotope Analysis of Feathers to Delineate Origins of Harvested Sandhill Cranes in the Central Flyway of North America|journal=Waterbirds|volume=29|issue=2|pages=137–147|doi=10.1675/1524-4695(2006)29[137:USHIAO]2.0.CO;2|s2cid=54943028 }}</ref> These techniques can be used in combination with other techniques such as ringing.<ref>{{cite book|author=Berthold, P., Gwinner, Eberhard and Sonnenschein, Edith |year=2003|title=Avian Migration|publisher=Springer|isbn=978-3540434085}}</ref>

The first attenuated vaccine developed by [[Louis Pasteur]], for fowl cholera, was tested on poultry in 1878.<ref>{{cite journal|author=Pasteur, Louis|year=1880|title=De l'attenuation du virus du chokra des poules|journal=Comptes Rendus de l'Académie des Sciences|volume=91|pages=673–680|url=http://www.asm.org/ccLibraryFiles/FILENAME/0000000222/1880p126.pdf|access-date=2010-08-29|archive-url=https://web.archive.org/web/20100612200422/http://asm.org/ccLibraryFiles/FILENAME/0000000222/1880p126.pdf|archive-date=2010-06-12|url-status=dead}}</ref> Anti-malarials were tested on birds which harbour avian-malarias.<ref>{{cite journal| author=Manwell, Reginald D. |year=1949| title= Malaria, birds and war. |jstor=9773656|journal=American Scientist |volume=37| issue=1| pages=60–68|pmid=18123477}}</ref> Poultry continues to be used as a model for many studies in non-mammalian immunology.<ref>{{Cite book|author=Davison, Fred, Bernd Kaspers & Karel Schat (Eds.)|year=2008|publisher=Academic Press|isbn=978-0-12-370634-8|title=Avian Immunology}}</ref>

Studies in bird behaviour include the use of tamed and trained birds in captivity. Studies on [[bird intelligence]] and [[bird vocalization#Learning|song learning]] have been largely laboratory-based. Field researchers may make use of a wide range of techniques such as the use of dummy owls to elicit mobbing behaviour, and dummy males or the use of call playback to elicit territorial behaviour and thereby to establish the boundaries of bird territories.<ref>{{cite journal|author=Slater, P. J. B.|year=2003|title=Fifty years of bird song research: a case study in animal behaviour|journal=Animal Behaviour|volume=65|pages=633–639|doi=10.1006/anbe.2003.2051|issue=4|s2cid=53157104|url=http://www.escholarship.org/uc/item/6bz1v7pf}}</ref>[[File:EmlenFunnel.svg|thumb|An Emlen funnel is used to study the orientation behaviour of migratory birds in a laboratory. Experimenters sometimes place the funnel inside a planetarium to study night migration.]] Studies of [[bird migration]] including aspects of navigation, orientation, and physiology are often studied using captive birds in special cages that record their activities. The [[Emlen funnel]], for instance, makes use of a cage with an inkpad at the centre and a conical floor where the ink marks can be counted to identify the direction in which the bird attempts to fly. The funnel can have a transparent top and visible cues such as the direction of sunlight may be controlled using mirrors or the positions of the stars simulated in a [[planetarium]].<ref>{{cite journal|author1=Emlen, S. T.  |author2=Emlen, J. T.  |name-list-style=amp |year=1966|title=A technique for recording migratory orientation of captive birds|jstor=4083048|url=http://sora.unm.edu/node/21524|journal=Auk|volume=83|pages=361–367|doi=10.2307/4083048|issue=3|doi-access=free}}</ref>

The entire genome of the domestic fowl (''[[Gallus gallus]]'') was sequenced in 2004, and was followed in 2008 by the genome of the zebra finch (''[[Taeniopygia guttata]]'').<ref>{{cite web |url=http://songbirdgenome.org/ |title=Zebra finch genome assembly release |access-date=7 May 2009 |date=6 Aug 2008 |publisher=The songbird genome sequencing project |archive-url=https://web.archive.org/web/20090805084309/http://songbirdgenome.org/ |archive-date=5 August 2009 |url-status=dead }}</ref>  Such whole-genome sequencing projects allow for studies on evolutionary processes involved in [[speciation]].<ref>{{cite journal|title=Identification of Birds through DNA Barcodes|vauthors=Hebert PD, Stoeckle MY, Zemlak TS, Francis CM |journal=PLOS Biology|volume= 2|issue=10|pages=e312|doi=10.1371/journal.pbio.0020312|year=2004|pmid=15455034|pmc=518999 |doi-access=free }}</ref> Associations between the expression of genes and behaviour may be studied using candidate genes. Variations in the exploratory behaviour of great tits (''[[Parus major]]'') have been found to be linked with a gene orthologous to the human gene ''[[DRD4]]'' (Dopamine receptor D4) which is known to be associated with novelty-seeking behaviour.<ref>{{cite journal |vauthors=Fidler AE, van Oers K, Drent PJ, Kuhn S, Mueller JC, Kempenaers B |title=Drd4 gene polymorphisms are associated with personality variation in a passerine bird |journal=Proc. Biol. Sci. |volume=274 |issue=1619 |pages=1685–91 |year=2007  |pmid=17472912 |pmc=1914334 |doi=10.1098/rspb.2007.0337 }}</ref> The role of gene expression in developmental differences and morphological variations have been studied in [[Darwin's finches]]. The difference in the expression of ''Bmp4'' have been shown to be associated with changes in the growth and shape of the beak.<ref>{{cite journal|last1=Abzhanov |first1=Arhat | last2=Protas | first2=Meredith |last3=Grant | first3=Peter R. | last4=Tabin | first4=Clifford J. |year=2004|title=Bmp4 and morphological variation of beaks in Darwin's finches|journal=Science|volume=305|pages=1462–1465|doi=10.1126/science.1098095|pmid=15353802|issue=5689|bibcode = 2004Sci...305.1462A |s2cid=17226774 }}</ref><ref>{{cite journal|title=High-speed developments in avian genomics|last1=Bonneaud | first1=Camille | last2=Burnside | first2=Joan |last3=Edwards | first3=Scott V. |name-list-style=amp |journal=BioScience|year=2008|volume=58|issue=7|pages=587–595|doi=10.1641/B580706|s2cid=17239411 |url=https://dash.harvard.edu/bitstream/handle/1/2665788/Edwards_High-speedDevelopments.pdf?sequence=2|doi-access=free}}</ref>

The chicken has long been a [[model organism]] for studying vertebrate [[developmental biology]]. As the embryo is readily accessible, its development can be easily followed (unlike [[house mouse|mice]]). This also allows the use of [[electroporation]] for studying the effect of adding or silencing a gene. Other tools for perturbing their genetic makeup are chicken [[embryonic stem cell]]s and [[viral vector]]s.<ref>{{cite journal |last=Stern | first=Claudio D. |title=The chick; a great model system becomes even greater |journal=Dev. Cell |volume=8 |issue=1 |pages=9–17 |date=January 2005 |pmid=15621526 |doi=10.1016/j.devcel.2004.11.018|doi-access=free }}</ref>