Editing Eurasian tree sparrow

{{Short description|Species of bird}}
{{For|the North American bird|American tree sparrow}}
{{Featured article}}
{{pp-move|small=yes}}
{{Speciesbox
 | image               = Tree Sparrow August 2007 Osaka Japan.jpg
 | image_caption       = Adult of subspecies ''P. m. saturatus'' in [[Japan]]
 | image2              = Passer montanus.ogg
 | image2_caption      =  Eurasian tree sparrows calling, in [[Moscow, Russia]]
 | status              = LC
 | status_system       = IUCN3.1
 | status_ref          = <ref name="iucn status 19 November 2021">{{cite iucn |author=BirdLife International |date=2017 |title=''Passer montanus'' |volume=2017 |page=e.T22718270A119216586 |doi=10.2305/IUCN.UK.2017-3.RLTS.T22718270A119216586.en |access-date=19 November 2021}}</ref>
 | taxon               = Passer montanus
 | authority           = ([[Carl Linnaeus|Linnaeus]], [[10th edition of Systema Naturae|1758]])
 | range_map           = Passermontanusmap.png
 | range_map_caption   = '''Afro-Eurasian distribution'''
<div style="margin-left: 1em; text-align: left;">
<big>{{Legend2|#FFFF00|Breeding summer visitor|border=1px solid #aaa}}<br />{{Legend2|#007D10|Resident breeder|border=1px solid #aaa}}<br />{{Legend2|#00FFFF|Non-breeding winter visitor |border=1px solid #aaa}}</big>
</div>
 | synonyms            =
* ''Fringilla montana'' <small>[[Carl Linnaeus|Linnaeus]], [[10th edition of Systema Naturae|1758]]</small>
* ''Loxia scandens'' <small>Hermann 1783</small>
* ''Passer arboreus'' <small>Foster 1817</small>
}}

The '''Eurasian tree sparrow''' ('''''Passer montanus''''') is a [[passerine]] bird in the [[Old World sparrow|sparrow]] family with a rich chestnut [[Crown (anatomy)|crown]] and [[nape]] and a black patch on each pure white cheek. The sexes are similarly [[plumage]]d, and young birds are a duller version of the adult. This sparrow breeds over most of [[Palearctic|temperate Eurasia]] and [[Southeast Asia]], where it is known as the '''tree sparrow''', and it has been introduced elsewhere including the [[United States]], where it is known as the Eurasian tree sparrow or '''German sparrow''' to differentiate it from the native unrelated [[American tree sparrow]]. Although several subspecies are recognised, the appearance of this bird varies little across its extensive range.

The Eurasian tree sparrow's untidy nest is built in a natural cavity, a hole in a building, or the disused nest of a [[European magpie]] or [[white stork]]. The typical [[clutch (eggs)|clutch]] is five or six eggs which hatch in under two weeks. This sparrow feeds mainly on seeds, but invertebrates are also consumed, particularly during the breeding season. As with other small birds, infection by parasites and diseases, and predation by [[birds of prey]] take their toll, and the typical life span is about two years.

The Eurasian tree sparrow is widespread in the towns and cities of eastern [[Asia]], but in [[Europe]], it is a bird of lightly wooded open countryside, with the [[house sparrow]] breeding in the more urban areas. The Eurasian tree sparrow's extensive range and large population ensure that it is not endangered globally, but there have been large declines in western European populations, in part due to changes in farming practices involving increased use of [[herbicide]]s and loss of winter [[crop residue|stubble]] fields. In eastern Asia and western [[Australia]], this species is sometimes viewed as a pest, although it is also widely celebrated in oriental art.

==Description==
The Eurasian tree sparrow is {{convert|12.5|–|14|cm|in|frac=2|abbr=on}} long,<ref name= Mullarney/> with a [[wingspan]] of about {{convert|21|cm|in|abbr=on}} and a weight of {{convert|24|g|oz|abbr=on}},<ref name =BTO>{{cite web| title= Tree Sparrow ''Passer montanus'' Linnaeus, 1758 |work= Bird facts | url= http://blx1.bto.org/birdfacts/results/bob15980.htm | publisher=[[British Trust for Ornithology]] |access-date=30 January 2009}}</ref> making it roughly 10% smaller than the house sparrow.<ref name = BWP>{{Harvnb|Snow|Perrins|1998|pp=1513–1515}}</ref> The adult's crown and nape are rich [[chestnut (color)|chestnut]], and there is a kidney-shaped black ear patch on each pure white cheek; the chin, throat, and the area between the bill and throat are black. The upperparts are light brown, streaked with black, and the brown wings have two distinct narrow white bars. The legs are pale brown, and the bill is lead-blue in summer, becoming almost black in winter.<ref name= Clement/>

This sparrow is distinctive even within its genus in that it has no plumage differences between the sexes; the juvenile also resembles the adult, although the colours tend to be duller.<ref>{{Harvnb|Mullarney|Svensson|Zetterstrom|Grant|1999|p=343}}</ref> Its contrasting face pattern makes this species easily identifiable in all plumages;<ref name= BWP/> the smaller size and brown, not grey, crown are additional differences from the male house sparrow.<ref name= Mullarney>{{Harvnb|Mullarney|Svensson|Zetterstrom|Grant|1999|p=342}}</ref> Adult and juvenile Eurasian tree sparrows undergo a slow complete [[moult]] in the autumn, and show an increase in body mass despite a reduction in stored fat. The change in mass is due to an increase in blood volume to support active feather growth and a generally higher water content in the body.<ref>{{cite journal | last= Lind | first= Johan | author2= Gustin, Marco | author3= Sorace, Alberto | year= 2004 | title= Compensatory bodily changes during moult in Tree Sparrows ''Passer montanus'' in Italy | journal= Ornis Fennica | volume= 81 | pages= 1–9 | url= http://www.zoologi.su.se/research/anti-predator/LindEtAl2004OrnFenn.pdf | url-status= dead | archive-url= https://web.archive.org/web/20151107052833/http://www.zoologi.su.se/research/anti-predator/LindEtAl2004OrnFenn.pdf | archive-date= 2015-11-07 }}</ref>

The Eurasian tree sparrow has no true song, but its [[bird vocalization|vocalisations]] include an excited series of ''tschip'' calls given by unpaired or courting males. Other monosyllabic chirps are used in social contacts, and the flight call is a harsh ''teck''.<ref name= BWP/> A study comparing the vocalisations of the introduced Missouri population with those of birds from [[Germany]] showed that the US birds had fewer shared syllable types ([[meme]]s) and more structure within the population than the European sparrows. This may have resulted from the small size of the founding North American population and a consequent loss of [[genetic diversity]].<ref name=lang>{{cite journal| last= Lang | first= A. L. |author2=Barlow, J. C.| year=1997 | title= Cultural evolution in the Eurasian Tree Sparrow: Divergence between introduced and ancestral populations | journal= [[The Condor (journal)|The Condor]] | volume=99 | issue= 2| pages=413–423| doi =10.2307/1369948 | jstor = 1369948|url=http://sora.unm.edu/sites/default/files/journals/condor/v099n02/p0413-p0423.pdf}}</ref>

==Taxonomy==
[[File:Linnaeuspage183.jpg|thumb|alt=page from an old book|Description of the house and Eurasian tree sparrows from the ''Systema naturae''<ref>Although Linnaeus gives the location as simply ''in Europa'', the type specimen was from [[Bagnacavallo]], Italy ({{cite journal| last= Clancy | first= Philip Alexander| year= 1948 |journal= [[Bulletin of the British Ornithologists' Club]]| title = Remarks on ''Passer montanus'' (Linnaeus) in the Western Palaearctic Region with special reference to ''Passer catellatus'' Kleinschmidt, 1935: England| volume= 68 |page= 135}}) Linnaeus's text for the tree sparrow translates "F[inch]. With dusky wings and tail, black and grey body paired white wing bars."</ref>]]
The [[Old World sparrow]] genus ''[[Passer]]'' is a group of small [[passerine]] birds that is believed to have originated in Africa, and which contains 15–25 species depending on the authority.<ref>{{Harvnb|Anderson|2006| p=5}}</ref> Its members are typically found in open, lightly wooded, habitats, although several species, notably the [[house sparrow]] (''P. domesticus'') have adapted to human habitations. Most species in the genus are typically {{convert|10|–|20|cm|in|abbr=on}} long, predominantly brown or greyish birds with short square tails and stubby conical beaks. They are primarily ground-feeding seed-eaters, although they also consume invertebrates, especially when breeding.<ref>{{Harvnb|Clement|Harris|Davis|1993| pp=442–467}}</ref> The Eurasian species is not closely related to the [[American tree sparrow]] (''Spizelloides arborea''), which is in a different family, the [[New World sparrow]]s.<ref>{{Harvnb|Byers|Curson|Olsson|1995| pp=267–268}}</ref>

The Eurasian tree sparrow's binomial name is derived from two [[Latin]] words: ''passer'', "sparrow", and ''montanus'', "of the mountains" (from ''mons'' "mountain").<ref name =BTO/> The Eurasian tree sparrow was first described by [[Carl Linnaeus]] in his 1758 ''[[Systema Naturae]]'' as ''Fringilla montana'',<ref>{{Harvnb|Linnaeus|1758| p=183}} ''F. remigibus rectricibusque fuscis, corpore griseo nigroque, alarum fascia alba gemina''</ref> but, along with the house sparrow, it was soon moved from the [[finch]]es (family Fringillidae) into the new genus ''Passer'' created by French zoologist [[Mathurin Jacques Brisson]] in 1760.<ref>{{Harvnb|Brisson|1760|p=36}}</ref> The Eurasian tree sparrow's common name is given because it prefers tree holes for nesting. This name, and the scientific name ''montanus'', do not appropriately describe this species's habitat preferences: the [[German language|German]] name ''Feldsperling'' and the [[Hungarian language|Hungarian]] name ''mezei veréb'' ("field sparrow") comes closer to doing so.<ref>{{Harvnb|Summers-Smith|1988|p=217}}</ref>

===Subspecies===

<gallery mode="packed" heights="100">
File:Tree-Sparrow-2009-16-02.jpg|''P. m. montanus''
File:Eurasian Tree Sparrow Passer montanus Nathang Valley Sikkim India 03.11.2014.jpg|''P. m. tibetanus''
File:Passer montanus saturatus.JPG|''P. m. saturatus''
File:Passer montanus malaccensis @ Kuala Lumpur, Malaysia (1).jpg|''P. m. malaccensis''
File:Eurasian Treesparrow Khonoma Nagaland India 05.11.2016.jpg|''P. m. hepaticus''
</gallery>
This species varies little in appearance across its large range, and the differences between the seven extant [[subspecies]] recognised by Clement are slight. At least 15 other subspecies have been proposed, but they are considered to be intermediates of the listed subspecies.<ref name= Clement>{{Harvnb|Clement|Harris|Davis|1993|pp=463–465}}</ref><ref>{{cite journal|last1= Vaurie |first1= Charles|last2=Koelz|first2=W. |year=1949|title=Notes on some Ploceidae from western Asia|journal=American Museum Novitates |issue=1406|pages=22–26|hdl=2246/2345}}</ref>
* The '''European tree sparrow''' (''P. m. montanus''), the [[Subspecies#Nomenclature|nominate subspecies]], ranges across Europe except for the southwestern [[Iberian Peninsula]], southern Greece and the former [[Yugoslavia]]. It also breeds in Asia east to the [[Lena River]] and south to the northern regions of [[Turkey]], the [[Caucasus]], Kazakhstan and [[Mongolia]] and in [[North Korea]].
* The '''Caucasian tree sparrow''' (''P. m. transcaucasicus''), described by [[Sergei Aleksandrovich Buturlin]] in 1906, breeds from the southern regions of the Caucasus east to northern [[Iran]]. It is duller and greyer than the nominate subspecies.<ref name = Clement/>
* The '''Afghan tree sparrow''' (''P. m. dilutus''), described by [[Charles Wallace Richmond]] in 1856, is resident in extreme northeastern Iran, northern [[Pakistan]] and northwestern [[India]]. It also occurs further north, from Uzbekistan and Tajikistan east to [[China]]. Compared to ''P. m. montanus'', it is paler, with sandy-brown upperparts.<ref name = Clement/>
* The '''Tibetan tree sparrow''' (''P. m. tibetanus''), the largest subspecies by size, was described by [[E. C. Stuart Baker|Stuart Baker]] in 1925. It is found in the northern [[Himalayas]], from [[Nepal]] east through [[Tibet]] to northwestern China. It resembles ''P. m. dilutus'', but is darker.<ref name = Clement/>
* ''P. m. saturatus'', described by [[Leonhard Hess Stejneger]] in 1885, breeds in [[Sakhalin]], the [[Kuril Islands]], [[Japan]], [[Taiwan]] and [[South Korea]]. It is deeper brown than the nominate subspecies and has a larger bill.<ref name = Clement/>
* ''P. m. malaccensis'', described by [[Alphonse Joseph Charles Dubois|Alphonse Dubois]] in 1885, is found from the southern Himalayas east to [[Hainan]] and [[Indonesia]]. It is a dark-coloured subspecies, like ''P. m. saturatus'', but is smaller and more heavily streaked on its upperparts.<ref name = Clement/>
* ''P. m. hepaticus'', described by [[Sidney Dillon Ripley]] in 1948, breeds from northeastern [[Assam]] to northwestern [[Burma]]. It is similar in appearance to ''P. m. saturatus'', but redder on its head and upperparts.<ref name = Clement/>

==Distribution and habitat==
[[File:Nest of Passer montanus B.jpg|thumb|right|Urban nest under a roof tile of a wooden house in Japan]]
[[File:Passer montanus - suzume - ueno park - 2013 11 8.webm|thumb|Eurasian tree sparrows in [[Japan]]]]
The Eurasian tree sparrow's natural breeding range comprises most of [[temperateness|temperate]] Europe and Asia south of about [[68th parallel north|latitude 68°N]] (north of this the summers are too cold, with July average temperatures below {{convert|12|C|F}}) and through Southeast Asia to [[Java]] and [[Bali]]. It formerly bred in the [[Faroe Islands|Faroes]], [[Malta]] and [[Gozo]].<ref name= BWP/><ref name= Clement/> In South Asia it is found mainly in the temperate zone.<ref>{{cite journal | last1 = Krishna Raju | first1 = K. S. R. | last2 = Price | first2= Trevor D. | year = 1973 | title = Tree Sparrow ''Passer montanus'' (L.) in the Eastern Ghats |journal = Journal of the Bombay Natural History Society | volume = 70 | issue = 3| pages = 557–558|url=https://biodiversitylibrary.org/page/48290564 }}</ref><ref name = Rasmussen>{{Harvnb|Rasmussen|Anderton|2005|location=Volume 2. p. 576}}</ref> It is sedentary over most of its extensive range, but northernmost breeding populations [[bird migration|migrate]] south for the winter,<ref>{{Harvnb|Arlott|2007|p=222}}</ref> and small numbers leave southern Europe for North Africa and the Middle East.<ref name= BWP/> The eastern subspecies ''P. m. dilutus'' reaches coastal Pakistan in winter and thousands of birds of this race move through eastern China in autumn.<ref name= Clement/>

The Eurasian tree sparrow has been [[introduced species|introduced]] outside its native range but has not always become established, possibly due to competition with the house sparrow. It was introduced successfully to [[Sardinia]],<ref name="europarlqsard">{{citation | url=http://www.europarl.europa.eu/doceo/document/E-5-2004-0801_EN.html | title=Exceptional hunting and wild bird conservation - Sardinia | date=2 March 2004 | first=Monica | last=Frassoni | publisher=[[European Parliament]]}}</ref><ref name="Barlow-et-al-2020">{{cite journal | last1=Barlow | first1=Jon C. | last2=Leckie | first2=Sheridan N. | last3=Pyle | first3=Peter | last4=Patten | first4=Michael A. | title=Eurasian Tree Sparrow (''Passer montanus''), version 1.0 | journal=[[Birds of the World]] | date=2020-03-04 | doi=10.2173/bow.eutspa.01 | s2cid=216311528 | url=http://birdsoftheworld.org/bow/species/eutspa/cur/introduction | access-date=2022-05-27| url-access=subscription }}</ref> eastern Indonesia, the Philippines and [[Micronesia]], but introductions to New Zealand and Bermuda did not take root. Ship-carried birds colonised [[Borneo]]. This sparrow has occurred as a natural [[vagrancy (biology)|vagrant]] to [[Gibraltar]], Tunisia, Algeria, Egypt, Israel, the United Arab Emirates,<ref name= Clement/> Morocco and Iceland.<ref name="iucn status 19 November 2021" />
In North America, a population of about 15,000 birds has become established around [[St. Louis, Missouri|St. Louis]] and neighbouring parts of Illinois and southeastern Iowa.<ref name=Cocker/> These sparrows are descended from 12 birds imported from Germany and released in late April 1870 as part of a project to enhance the native North American avifauna. Within its limited US range of about {{convert|22000|sqkm|sqmi}},<ref>{{cite web |editor1-last=del Hoyo |editor1-first=Josep |editor2-last=Elliott |editor2-first=Andrew |editor3-last=Sargatal |editor3-first=Jordi |editor4-last=Christie |editor4-first=David A. |editor5-last=de Juana |editor5-first=Eduardo |year=2013 |title= Eurasian Tree Sparrow (''Passer montanus'') |work=Handbook of the Birds of the World Alive | url=https://www.hbw.com/species/eurasian-tree-sparrow-passer-montanus |publisher=Lynx Edicions |location=Barcelona |access-date=25 October 2018 |url-access=subscription }}</ref> the Eurasian tree sparrow has to compete with the house sparrow in urban centres, and is therefore mainly found in parks, farms and rural woods.<ref name=lang/><ref>{{cite web| author = Barlow, Jon C.| author2 = Leckie, Sheridan N. | title= Eurasian Tree Sparrow (''Passer montanus'') | work= The Birds of North America Online |editor-first=A.|editor-last= Pool | url= http://bna.birds.cornell.edu/bna/species/560/articles/introduction | location= Ithaca |access-date=30 January 2009| publisher = Cornell Laboratory of Ornithology }}</ref> The American population is sometimes referred to as the "German sparrow", to distinguish it from both the native American tree sparrow species and the much more widespread "English" house sparrow.<ref>{{Harvnb|Forbush|1907|p=306}}</ref>

In Australia, the Eurasian tree sparrow is present in [[Melbourne]], towns in central and northern [[Victoria (Australia)|Victoria]] and some centres in the [[Riverina]] region of [[New South Wales]]. It is a prohibited species in [[Western Australia]], where it often arrives on ships from Southeast Asia.<ref name=oz>{{cite web|author=Massam, Marion |title=Sparrows |work=Farmnote No. 117/99 |url=http://www.agric.wa.gov.au/content/pw/vp/bird/f11799.pdf |publisher=Agriculture Western Australia |access-date=1 February 2009 |url-status=dead |archive-url=https://web.archive.org/web/20080812133121/http://www.agric.wa.gov.au/content/pw/vp/bird/f11799.pdf |archive-date=12 August 2008 }}</ref>

Despite its scientific name, ''Passer montanus'', this is not typically a mountain species, and reaches only {{convert|700|m|ft|abbr=on}} in Switzerland, although it has bred at {{convert|1,700|m|ft|abbr=on}} in the northern Caucasus and as high as {{convert|4,270|m|ft|abbr=on}} in Nepal.<ref name= BWP/><ref name= Clement/> In Europe, it is frequently found on coasts with cliffs, in empty buildings, in [[pollarding|pollarded]] willows along slow water courses, or in open countryside with small isolated patches of woodland.<ref name= BWP/> The Eurasian tree sparrow shows a strong preference for nest-sites near [[wetland]] habitats and avoids breeding on intensively managed mixed farmland.<ref name= field>{{cite journal| last= Field| first= Rob H. |author2=Anderson, Guy | year= 2004| title= Habitat use by breeding Tree Sparrows ''Passer montanus'' | journal= [[Ibis (journal)|Ibis]] | volume=146 | issue= 2| pages=60–68 |doi =10.1111/j.1474-919X.2004.00356.x| doi-access= free }}</ref>

When the Eurasian tree sparrow and the larger house sparrow occur in the same area, the house sparrow generally breeds in urban areas while the smaller Eurasian tree sparrow nests in the countryside.<ref name= Clement/> Where trees are in short supply, as in Mongolia, both species may utilise man-made structures as nest sites.<ref>{{cite journal|last=Melville |first=David S. |author2=Carey, Geoff J. |year=1998 |title=Syntopy of Eurasian Tree Sparrow ''Passer montanus'' and House Sparrow ''P. domesticus'' in Inner Mongolia, China |journal=[[Forktail (journal)|Forktail]] |volume=13 |url=http://www.orientalbirdclub.org/publications/forktail/13pdfs/Melville-Sparrows.pdf |page=125 |url-status=dead |archive-url=https://web.archive.org/web/20110610175224/http://www.orientalbirdclub.org/publications/forktail/13pdfs/Melville-Sparrows.pdf |archive-date=2011-06-10 }}</ref> The Eurasian tree sparrow is rural in Europe, but is an urban bird in eastern Asia; in southern and central Asia, both ''Passer'' species may be found around towns and villages.<ref name = Clement/> In parts of the Mediterranean, such as Italy, both the tree and the Italian or Spanish sparrows may be found in settlements.<ref name="Summers-Smith 1988 220">{{Harvnb|Summers-Smith|1988|p=220}}</ref> In Australia, the Eurasian tree sparrow is largely an urban bird, and it is the house sparrow which utilises more natural habitats.<ref name = oz/>
[[File:Eurasian-Tree-Sparrow.jpg|thumb|In flight]]

==Behaviour and ecology==

===Breeding===
[[File:Passer montanus montanus MHNT.ZOO.2010.11.209.jpg|thumb|[[Museum de Toulouse]]|alt=Eggs, [[Museum de Toulouse]]]]
[[File:TreeSparrow 20080703.JPG|thumb|[[Fledge|Fledgling]]]]
[[File:Pilfink (Passer montanus) - Ystad-2023.jpg|thumb|One adult and two juveniles]]
The Eurasian tree sparrow reaches breeding maturity within a year from hatching,<ref name = anage/> and typically builds its nest in a cavity in an old tree or rock face. Some nests are not in holes as such, but are built among roots of overhanging [[gorse]] or similar bush.<ref name=Coward/> Roof cavities in houses may be used,<ref name=Coward/> and in the tropics, the crown of a palm tree or the ceiling of a verandah can serve as a nest site.<ref name= robinson>{{Harvnb|Robinson|Chasen|1927–1939|loc=[http://rmbr.nus.edu.sg/biblio/robinson_chasen/vol1/55_True%20Finches.pdf Chapter 55] (PDF) 284–285}}</ref>  This species will breed in the disused domed nest of a [[European magpie]],<ref name=Coward>{{Harvnb|Coward|1930|pp=56–58}}</ref> or an active or unused stick nest of a large bird such as the [[white stork]],<ref>{{cite journal|last=Bochenski |first=Marcin |url=http://www.wnb.uz.zgora.pl/assets/files/iss/iss_vol30_04.pdf |archive-url=https://web.archive.org/web/20110924000607/http://iss.wnb.uz.zgora.pl/assets/files/prints/iss/iss_vol30.pdf |archive-date=24 September 2011 |title=Nesting of the sparrows ''Passer'' spp. in the White Stork ''Ciconia ciconia'' nests in a stork colony in Klopot (W Poland) |editor-last=Pinowski |editor-first=Jan |journal=International Studies on Sparrows |volume=30 |year=2005 |pages=39–41 |url-status=dead }}</ref> [[white-tailed eagle]], [[osprey]], [[black kite]] or [[grey heron]]. It will sometimes attempt to take over the nest of other birds that breed in holes or enclosed spaces, such as the [[barn swallow]], [[Common house martin|house martin]], [[sand martin]] or [[European bee-eater]].<ref>{{cite journal|last=Czechowski |first=Pawel |journal=International Studies on Sparrows |title=Nesting of Tree Sparrow ''Passer montanus'' in the nest of Barn Swallow ''Hirundo rustica'' |editor-last=Pinowski |editor-first=Jan |volume=32 |year=2007 |pages=35–37 |url=http://iss.wnb.uz.zgora.pl/assets/files/prints/iss/iss_vol32.pdf |archive-url=https://web.archive.org/web/20110924000600/http://iss.wnb.uz.zgora.pl/assets/files/prints/iss/iss_vol32.pdf |archive-date=24 September 2011 |url-status=dead }}</ref>

Pairs may breed in isolation or loose colonies,<ref>{{cite journal|last1=Hegyi|first1=Z.|last2=Sasvári|first2=L.|year=1994|url=http://kornel.zool.klte.hu/pub/ornis/articles/OrnisHungarica_vol4_p9-18.pdf|title=Alternative reproductive tactics as viable strategies in the Tree Sparrow (''Passer montanus'')|journal=Ornis Hungaria|volume=4|pages=9–18|access-date=2009-01-31|archive-date=2011-07-21|archive-url=https://web.archive.org/web/20110721110450/http://kornel.zool.klte.hu/pub/ornis/articles/OrnisHungarica_vol4_p9-18.pdf|url-status=dead}}</ref> and will readily use [[nest box]]es. In a Spanish study, boxes made from a mixture of wood and concrete (woodcrete) had a much higher occupancy rate than wooden boxes (76.5% versus 33.5%), and birds nesting in woodcrete sites had earlier clutches, a shorter incubation period and more breeding attempts per season. Clutch size and chick condition did not differ between nest box types, but reproductive success was higher in woodcrete, perhaps because the synthetic nests were 1.5&nbsp;°C warmer than their wooden counterparts.<ref>{{cite journal| last= García-Navas | first= Vicente | author2= Arroyo, Luis | author3= Sanz, Juan José | author4= Díaz, Mario | year= 2008 | title= Effect of nestbox type on occupancy and breeding biology of tree sparrows ''Passer montanus'' in central Spain | journal= [[Ibis (journal)|Ibis]] | volume=150 | issue= 2| pages=356–364 | url = http://www.ccma.csic.es/index.php/es/def/pdf1330?modelo=publicacion|archive-url=https://web.archive.org/web/20100930134423/http://www.ccma.csic.es/index.php/es/def/pdf1330?modelo=publicacion|archive-date=30 September 2010 |format = PDF | doi =10.1111/j.1474-919X.2008.00799.x| hdl= 10261/110551 | hdl-access= free }}</ref>

The male calls from near the nest site in spring to proclaim ownership and attract a mate. He may also carry nest material into the nest hole.<ref name= Clement/> The display and nest building are repeated in autumn. The preferred locations for the autumn display are old Eurasian tree sparrow nests, particularly those where nestlings had hatched. Empty nest boxes, and sites used by house sparrows or other hole nesting birds, such as [[tit (bird)|tits]], [[European pied flycatcher|pied flycatchers]] or [[common redstart]]s, are rarely used for the autumn display.<ref name= Pinowski>{{cite journal| last= Pinowski | first= Jan |author2=Pinowska, Barbara |author3=Barkowska, Miloslawa |author4=Jerzak, Leszek |author5=Zduniak, Piotr |author6= Tryjanowski, Piotr  |date=June 2006 | title= Significance of the breeding season for autumnal nest-site selection by Tree Sparrows ''Passer montanus'' | journal= Acta Ornithologica | volume=41 | issue= 1| pages= 83–87| doi =10.3161/068.041.0103 | doi-access=free }}</ref>

The untidy nest is composed of hay, grass, [[wool]] or other material and lined with [[feather]]s,<ref name=Coward/> which improve the thermal insulation.<ref>{{cite journal|last=Pinowski |first=Jan |author2=Haman, Andrzej |author3=Jerzak, Leszek |author4=Pinowska, Barbara |author5=Barkowska, Miloslawa |author6=Grodzki, Andrzej |author7=Haman, Krzysztof |year=2006 |url=http://www.wnb.uz.zgora.pl/static/wnb.uz.arch/assets/files/ljerzak/pinowski_jerzak_thermal.pdf |title=The thermal properties of some nests of the Eurasian Tree Sparrow ''Passer montanus'' |journal=Journal of Thermal Biology |volume=31 |pages=573–581 |doi=10.1016/j.jtherbio.2006.05.007 |issue=7 |bibcode=2006JTBio..31..573P |archive-url=https://web.archive.org/web/20111031150540/http://www.wnb.uz.zgora.pl/static/wnb.uz.arch/assets/files/ljerzak/pinowski_jerzak_thermal.pdf |archive-date=31 October 2011 |url-status=dead }}</ref> A complete nest consists of three layers; base, lining and dome.<ref name= Pinowski/> The typical clutch is five or six [[Egg (biology)|eggs]] (rarely more than four in Malaysia),<ref name= robinson/> white to pale grey and heavily marked with spots, small blotches, or speckling;<ref>{{cite web|title= Eurasian Tree Sparrow ''Passer montanus'' | work= Bird guide |url = http://www.birds.cornell.edu/AllAboutBirds/BirdGuide/Eurasian_Tree_Sparrow_dtl.html | publisher= Cornell Laboratory of Ornithology |access-date=30 January 2009 }}</ref> they are {{convert|20|x|14|mm|in|abbr=on}} in size and weigh {{convert|2.1|g|oz|abbr=on}}, of which 7% is shell.<ref name =BTO/> The eggs are incubated by both parents for 12–13 days before the [[altricial]], naked chicks hatch, and a further 15–18 days elapse before they [[fledge]]. Two or three broods may be raised each year;<ref name =BTO/> birds breeding in colonies produce more eggs and fledglings from their first broods than solitary pairs, but the reverse is true for second and third clutches.<ref>{{cite journal| last= Sasvari| first= L. |author2=Hegyi, Z. |year=1994 | title= Colonial and solitary nesting choice as alternative breeding tactics in tree sparrow ''Passer montanus'' | journal= [[Journal of Animal Ecology]] | volume= 63| issue= 2| pages=265–274| doi = 10.2307/5545| jstor= 5545| bibcode= 1994JAnEc..63..265S }}</ref> Females that copulate frequently tend to lay more eggs and have a shorter incubation time, so within-pair mating may be an indicator of the pairs' reproductive ability.<ref>{{cite journal| last= Heeb | first= P. |date=June 2001 | title= Pair copulation frequency correlates with female reproductive performance in Tree Sparrows ''Passer montanus'' | journal= [[Journal of Avian Biology]] | volume=32 | issue= 2 | pages=120–126 | doi =10.1034/j.1600-048X.2001.320204.x }}</ref> There is a significant level of promiscuity; in a Hungarian study, more than 9% of chicks were sired by extra-pair males, and 20% of the broods contained at least one extra-pair young.<ref>{{cite journal| last= Seress | first= G. | author2= Szabó, K. | author3= Nagy, D. | author4= Liker, A. | author5= Pénzes, Z.|year=2007 | title= Extra-pair paternity of tree sparrow (''Passer montanus'') in a semi-urban population | journal= TISCIA | volume=36 |pages=17–21 | url = http://expbio.bio.u-szeged.hu/ecology/tiscia/t_36_3_seress.pdf |archive-url=https://web.archive.org/web/20081209103039/http://expbio.bio.u-szeged.hu/ecology/tiscia/t_36_3_seress.pdf|archive-date=9 December 2008}}</ref>

[[Hybrid (biology)|Hybridisation]] between the Eurasian tree sparrow and the house sparrow has been recorded in many parts of the world with male hybrids tending to resemble the Eurasian tree sparrow while females have more similarities with the house sparrow.<ref>{{cite journal| last= Cordero | first= P. | year=1991 | title= Phenotypes of adult hybrids between House Sparrows ''Passer domesticus'' and Tree Sparrow ''Passer montanus'' | journal= [[Bulletin of the British Ornithologists' Club]] | volume=111 |pages=44–46}}</ref> A breeding population in the [[Eastern Ghats]] of India,<ref>{{cite journal|last1=Raju|first1= K. S. R. Krishna|last2=Price|first2=Trevor D. |year=1973|title= Tree Sparrow ''Passer montanus'' (L.) in the Eastern Ghats| journal= J. Bombay Nat. Hist. Soc.|volume=70|issue=3|pages=557–558}}</ref> said to be introduced,<ref name=Clement/> may also hybridise with house sparrows.<ref name = Rasmussen/> On at least one occasion a mixed pair has resulted in fertile young.<ref>{{cite journal|last=Solberg |first=Erling Johan |author2=Ringsby, Thor Harald |author3=Altwegg, Andreas |author4=Sæther, Bernt-Erik |date=January 2000 |title=Fertile House Sparrow X Tree Sparrow (''Passer domesticus'' × ''Passer montanus'') hybrids? |journal=[[Journal of Ornithology]] |volume=141 |issue=1 |pages=10–104 |url=http://www.nt.ntnu.no/users/thorhr/Publications/pdf/solberg%20et%20al%202000%20hybrid_2.pdf |doi=10.1007/BF01651777 |bibcode=2000JOrni.141..102S |s2cid=22342085 |url-status=dead |archive-url=https://web.archive.org/web/20110721080538/http://www.nt.ntnu.no/users/thorhr/Publications/pdf/solberg%20et%20al%202000%20hybrid_2.pdf |archive-date=2011-07-21 }}</ref><ref>{{cite journal|last=Solberg |first=E. J. |author2=Jensen, H. |author3=Ringsby, T. H. |author4=Sæther, B.-E. |year=2006 |url=http://www.nt.ntnu.no/users/thorhr/Publications/pdf/solberg%20et%20al%202006%20hybridization%20fitness_3.pdf |title=Fitness consequences of hybridization between house sparrows (''Passer domesticus'') and tree sparrows (''P. montanus'') |journal=[[Journal of Ornithology]] |volume=147 |pages=504–506 |doi=10.1007/s10336-005-0033-5 |issue=3 |bibcode=2006JOrni.147..504S |s2cid=36713880 |url-status=dead |archive-url=https://web.archive.org/web/20110721080557/http://www.nt.ntnu.no/users/thorhr/Publications/pdf/solberg%20et%20al%202006%20hybridization%20fitness_3.pdf |archive-date=2011-07-21 }}</ref><ref>{{cite journal|last1=Solberg |first1=E. J. |last2=Ringsby |first2=T. H. |year=1996 |url=http://www.nt.ntnu.no/users/thorhr/Publications/pdf/solberg%20et%20al%201996%20hybridisation_1%20.pdf |title=Hybridisation between house sparrow ''Passer domesticus'' and tree sparrow ''Passer montanus'' |journal=Journal für Ornithologie |volume=137 |issue=4 |pages=525–528 |doi=10.1007/BF01661107 |bibcode=1996JOrni.137..525S |s2cid=35504888 |url-status=dead |archive-url=https://web.archive.org/web/20110721080616/http://www.nt.ntnu.no/users/thorhr/Publications/pdf/solberg%20et%20al%201996%20hybridisation_1%20.pdf |archive-date=2011-07-21 }}</ref> A wild hybridisation with the resident sparrows of Malta, which are intermediate between the [[Spanish sparrow]] (''P. hispaniolensis'') and [[Italian sparrow]]s (''P. italiae''), was recorded in Malta in 1975.<ref name =Clement/>

===Feeding===
[[File:Passer montanus 050526.jpg|thumb|right|[[Nest box]] of [[woodcrete]]]]
[[File:Pilfink (Passer montanus) - Ystad-2022.jpg|thumb|A very social bird, no problem sharing a [[bird feeder]]]]
The Eurasian tree sparrow is a predominantly seed and grain-eating bird which feeds on the ground in flocks, often with house sparrows, finches, or buntings. It eats weed seeds, such as [[Caryophyllaceae|chickweeds]] and [[Chenopodium|goosefoot]], spilled grain,<ref name = Clement/> and it may also visit [[Bird feeder|feeding stations]], especially for [[peanut]]s. It will also feed on [[invertebrate]]s, especially during the breeding season when the young are fed mainly on animal food; it takes insects, [[woodlouse|woodlice]], [[millipede]]s, [[centipede]]s, [[spider]]s and [[Opiliones|harvestmen]].<ref name = naturalengland>{{cite web|title= Tree sparrow – ''Passer montanus'' – Family: Fringillidae/Passeridae |url=http://www.plantpress.com/wildlife/o52-treesparrow.php | publisher = [[Natural England]] |access-date=31 January 2009|archive-url=https://web.archive.org/web/20110720013056/http://www.plantpress.com/wildlife/o52-treesparrow.php|archive-date=20 July 2011}}</ref>

Adults use a variety of wetlands when foraging for invertebrate prey to feed nestlings, and aquatic sites play a key role in providing adequate diversity and availability of suitable invertebrate prey to allow successful chick rearing throughout the long breeding season of this multi-brooded species. Large areas of formerly occupied farmland no longer provide these invertebrate resources due to the effects of [[intensive farming]], and the availability of supplementary seed food within {{convert|1|km}} of the nest site does not influence nest-site choice, or affect the number of young raised.<ref name= field/>

In winter, seed resources are most likely to be a key limiting factor.<ref name= field/> At this time of year, individuals in a flock form linear [[Dominance hierarchy|dominance hierarchies]], but there is no strong relation between the size of the throat patch and position in that hierarchy. This is in contrast to the house sparrow; in that species, fights to establish dominance are reduced by the display of the throat patch, the size of which acts as a [[Signalling theory|signalling]] "badge" of [[Fitness (biology)|fitness]].<ref>{{cite journal|last=Torda|first=G.|author2= Liker, András|author3= Barta, Z. |year=2004|url=http://actazool.nhmus.hu/50/1/torda.pdf|title= Dominance hierarchy and status signalling in captive tree sparrow (''Passer montanus'') flocks|journal=[[Acta Zoologica Academiae Scientiarum Hungaricae]]|volume=50|issue=1|pages= 35–44}}</ref>  Although there is evidence that the black throat patch of male, but not female, tree sparrows predicts fighting success in foraging flocks.<ref>{{cite journal  | last1 = Mónus | first1 = Ferenc |last2 =  Liker| first2 =A | last3 = Pénzes | first3 = Zoltán| last4 = Barta | first4 = Zoltán | title = Status signalling in male but not in female Eurasian Tree Sparrows ''Passer montanus'' | journal = Ibis | volume = 159 | pages = 180–192 | year =  2017| doi = 10.1111/ibi.12425| url = http://real.mtak.hu/73486/1/MonusIBISmanu.pdf }}</ref>

The risk of predation affects feeding strategies. A study showed that increased distance between shelter and a food supply meant that birds visited a feeder in smaller flocks, spent less time on it and were more vigilant when far from shelter. Sparrows can feed as "producers", searching for food directly, or "scroungers", just joining other flock members who have already discovered food. Scrounging was 30% more likely at exposed feeding sites, although this is not due to increased anti-predator vigilance. A possible explanation is that riskier places are used by individuals with lower fat reserves.<ref>{{cite journal| last= Barta | first= Zoltán | author2= Liker, András | author3= Mónus, Ferenc |date=February 2004 | title=The effects of predation risk on the use of social foraging tactics | journal=Animal Behaviour | volume=67 | issue= 2 | pages=301–308 |doi =10.1016/j.anbehav.2003.06.012 | s2cid= 53180647 }}</ref>

===Prey===
[[File:Accnis edit.jpg|thumb|The [[Eurasian sparrowhawk]] is a widespread predator|180px]]
[[File:Pilfink - (Passer montanus) - Ystad-2024.jpg|thumb|180px|A sick and dying individual, apathetic and unresponsive to touch.]]
Predators of the Eurasian tree sparrow include a variety of [[accipiter]]s, [[falcon]]s and [[owl]]s, such as the [[Eurasian sparrowhawk]],<ref name = naturalengland/> [[common kestrel]],<ref>{{cite journal|last1=Costantini|first1= David|last2= Casagrande|first2= Stefania|last3= Di Lieto|first3=Giuseppe|last4=Fanfani|first4=Alberto|last5=Dell'Omo|first5=Giacomo|year=2005|url=http://www.birdcam.it/files/Behaviour2005.pdf |title=Consistent differences in feeding habits between neighbouring breeding kestrels|journal=Behaviour|volume=142|pages=1409–1421|archive-url=https://web.archive.org/web/20070710091202/http://www.birdcam.it/files/Behaviour2005.pdf|archive-date=10 July 2007|doi=10.1163/156853905774539409|issue=9}}</ref> [[little owl]],<ref>{{cite journal|last1=Shao|first1= M.|last2=Hounsome|first2= T.|last3=Liu|first3=N.|year=2007|title=The summer diet of the Little Owl (''Athene noctua'') in the desert of north-west China|journal=Journal of Arid Environments|volume=68|issue=4|pages=683–687|doi=10.1016/j.jaridenv.2006.08.010|bibcode= 2007JArEn..68..683S}}</ref><ref>{{cite journal|last1=Obuch|first1=Ján|last2=Kristin|first2=Anton|year=2004|url=http://www.ivb.cz/folia/53/1/65-79.pdf|title=Prey composition of the little owl ''Athene noctua'' in an arid zone (Egypt, Syria, Iran)|journal=Folia Zoologica|volume=53|issue=1|pages=65–79|access-date=2009-01-31|archive-url=https://web.archive.org/web/20110718173849/http://www.ivb.cz/folia/53/1/65-79.pdf|archive-date=2011-07-18|url-status=dead}}</ref> and sometimes [[long-eared owl]] and white stork.<ref>{{cite journal|last=Berthold|first=Peter |year=2004|title=Aerial "flycatching": non-predatory birds can catch small birds in flight|journal=[[Journal of Ornithology]]|volume=145|issue=3|pages=271–272|doi=10.1007/s10336-004-0041-x|bibcode=2004JOrni.145..271B |s2cid=41451240 }}</ref><ref>{{cite journal|last1=Bertolino|first1=Sandro|last2=Ghiberti|first2=Elena|last3=Perrone|first3=Aurelio |year=2001|title=Feeding ecology of the long-eared owl (''Asio otus'') in northern Italy: is it a dietary specialist? |journal=Canadian Journal of Zoology|volume=79|issue=12|pages=2192–2198|doi=10.1139/z01-182|bibcode=2001CaJZ...79.2192B }}</ref> It does not appear to be at an increased risk of predation during its autumn moult, despite having fewer flight feathers at that time.<ref>{{cite journal | last= Lind | first= J. | year= 2001 | title= Escape flight in moulting Eurasian Tree Sparrows (''Passer montanus'') | journal= Functional Ecology | volume= 15 | pages= 29–35 | doi= 10.1046/j.1365-2435.2001.00497.x | doi-access= free }}</ref> Nests may be raided by Eurasian [[magpie]]s, [[Eurasian jay|jay]]s, [[least weasel]]s, rats, cats, and constricting snakes such as the [[horseshoe whip snake]].<ref>{{cite journal| last= Veiga | first= J. P. | year=1990 | title= A comparative study of reproductive adaptations in house and tree sparrows | journal= [[The Auk]] | volume=107 | issue=1 | pages=45–59 | url =http://sora.unm.edu/sites/default/files/journals/auk/v107n01/p0045-p0059.pdf | jstor = 4087801 }}</ref><ref>Cordero, P. J.; Salaet, M. "Breeding season, population and reproduction rate of the tree sparrow (''Passer montanus'', L.) in Barcelona, NE Spain." in {{Harvnb|Pinowski|Summers-Smith|1990|pp=169–177}}</ref><ref>Cordero, P. J. "Predation in House Sparrow and Tree Sparrow (''Passer'' sp.) nests" in {{Harvnb|Pinowski|Kavanagh|Górski|1991|pp=111–120}}</ref>

Many species of [[Bird louse|bird lice]] are present on the birds and in their nests,<ref>{{cite journal|last=Skoracki|first= Maciej |year=2002|title=Three new species of the ectoparasitic mites of the genus ''Syringophiloidus'' Kethley, 1970 (Acari: Syringophilidae) from passeriform birds from Slovakia|journal=Folia Parasitologica|volume=49|pages= 305–313|pmid=12641205|issue=4|doi=10.14411/fp.2002.057|doi-access=free}}</ref><ref>{{cite journal|first1=Suthasanee|last1=Boonkong|first2=Wina|last2=Meckvichai|year=1987|url=http://www.scienceasia.org/1987.13.n4/v13_231_237.pdf|title=Arthropod parasites of the tree sparrow (''Passer montanus'' Linnaeus, 1758) in Bangkok, Thailand|journal=Journal of the Scientific Society of Thailand|volume=13|pages= 231–237|doi=10.2306/scienceasia1513-1874.1987.13.231|issue=4|doi-access=free}}</ref> and mites of the genus ''Knemidocoptes'' have been known to infest populations, resulting in lesions on the legs and toes.<ref>{{cite journal|last=Mainka|first=S. A.|author2=Melville D. S.|author3=Galsworthy A.|author4=Black, S. R.|year=1994|title=''Knemidocoptes'' sp. on wild passerines at the Mai Po nature reserve, Hong Kong|journal=Journal of Wildlife Diseases|volume=30|issue=2|pages=254–256|pmid=8028111|doi=10.7589/0090-3558-30.2.254|s2cid=40000445}}</ref> Parasitisation of nestlings by ''[[Protocalliphora]]'' [[blow-fly]] larvae is a significant factor in nestling mortality.<ref>{{cite journal|last=Puchala|first= Peter |year=2004|title=Detrimental effects of larval blow flies (''Protocalliphora azurea'') on nestlings and breeding success of Tree Sparrows (''Passer montanus'')|journal=Canadian Journal of Zoology|volume=82|issue=8|pages= 1285–1290|doi=10.1139/z04-111|bibcode= 2004CaJZ...82.1285P }}</ref> Egg size does not influence nestling mortality, but chicks from large eggs grow faster.<ref>{{cite journal| last= Pinowska | first= Barbara |author2=Barkowska, Miloslawa |author3=Pinowski, Jan |author4=Bartha, Andrzej |author5=Hahm, Kyu-Hwang |author6= Lebedeva, Natalia  | year=2004 | title= The effect of egg size on growth and survival of the Tree Sparrow ''Passer montanus'' nestlings | journal= Acta Ornithologica| volume=39 | issue=2 | pages=121–135 | doi =10.3161/068.039.0209| s2cid= 84542029 | url= http://rcin.org.pl/Content/55518 | doi-access=free }}</ref>

Eurasian tree sparrows are also subject to bacterial and viral infections. Bacteria have been shown to be an important factor in the failure of eggs to hatch and in nestling mortality,<ref>{{cite journal|last1=Pinowksi|first1=J.|last2=Barkowska|first2= M.|last3=Kruszewicz|first3= A. H.|last4=Kruszewicz |first4=A. G. |year=1994|url=http://www.ias.ac.in/jarch/jbiosci/19/441-451.pdf |title=The causes of the mortality of eggs and nestlings of ''Passer'' spp|journal=Journal of Biosciences|volume=19|issue=4|pages= 441–451|doi=10.1007/BF02703180|s2cid=34137788}}</ref> and mass deaths due to ''[[Salmonella]]'' infection have been noted in Japan.<ref>{{cite journal|first1=Yumi |last1=Une |first2=Asuka |last2=Sanbe |first3=Satoru |last3=Suzuki |first4=Takeshi |last4=Niwa |first5=Kazuto |last5=Kawakami |first6=Reiko |last6=Kurosawa |first7=Hidemasa |last7=Izumiya |first8=Haruo |last8=Watanabe |first9=Yukio |last9=Kato |year=2008 |url=http://www.nih.go.jp/JJID/61/166.pdf |title=''Salmonella enterica'' Serotype Typhimurium Infection Causing Mortality in Eurasian Tree Sparrows (''Passer montanus'') in Hokkaido |journal=Japan Journal of Infectious Diseases |volume=61 |issue=2 |pages=166–167 |pmid=18362416 |archive-url=https://web.archive.org/web/20110929150300/http://www.nih.go.jp/JJID/61/166.pdf |archive-date=29 September 2011 |url-status=dead }}</ref> [[Avian malaria]] parasites have been found in the blood of many populations,<ref>{{cite journal|last1=Shurulinkov|first1=Peter|last2=Golemansky|first2=Vassil |year=2003|url=http://www.nencki.gov.pl/pdf/ap/ap688.pdf |title=Plasmodium and Leucocytozoon (Sporozoa: Haemosporida) of wild birds in Bulgaria|journal=Acta Protozoolica|volume=42|pages= 205–214|archive-url=https://web.archive.org/web/20040613141733/http://www.nencki.gov.pl/pdf/ap/ap688.pdf|archive-date=13 June 2004}}</ref> and birds in China were found to harbour a strain of [[Influenza A virus subtype H5N1|H5N1]] that was highly virulent to chickens.<ref>{{cite journal |year=2005|url= |title=New genotype of Avian Influenza H5N1 Viruses isolated from Tree Sparrows in China|journal=Journal of Virology|volume=79|issue=24|pages= 15460–15466|author1=Kou, Z. |author2=Lei, F. M. |author3=Yu, J. |author4=Fan, Z. J. |author5=Yin, Z. H. |author6=Jia, C. X. |author7=Xiong, K. J. |author8=Sun, Y. H. |author9=Zhang, X. W. |author10=Wu, X. M. |author11=Gao, X. B. |author12=Li, T. X. |doi=10.1128/JVI.79.24.15460-15466.2005 |pmid=16306617 |pmc=1316012}}</ref>

The immune response of Eurasian tree sparrows is less robust than that of the house sparrow and has been proposed as a factor in the greater invasive potential of the latter.<ref>{{cite journal|last=Lee |first=Kelly A. |author2=Martin, Lynn B. II |author3=Wikelski, Martin C. |year=2005 |url=http://www.princeton.edu/~wikelski/Publications/2005%20lee%20et%20al.pdf |title=Responding to inflammatory challenges is less costly for a successful avian invader, the house sparrow (''Passer domesticus''), than its less-invasive congener |journal=Oecologia |volume=145 |issue=2 |pages=244–251 |pmid=15965757 |doi=10.1007/s00442-005-0113-5 |bibcode=2005Oecol.145..243L |s2cid=13394657 |url-status=dead |archive-url=https://web.archive.org/web/20060921034010/http://www.princeton.edu/~wikelski/Publications/2005%20lee%20et%20al.pdf |archive-date=2006-09-21 }}</ref> The house sparrow and Eurasian tree sparrow are the most frequent victims of [[roadkill]] on the roads of Central, Eastern and Southern Europe.<ref>{{cite journal|author1=Erritzoe, J. |author2=Mazgajski, T. D. |author3=Rejt, L. |year=2003|url=http://www.birdresearch.dk/unilang/articles/traffic.pdf|title=Bird casualties on European roads — a review|journal=Acta Ornithologica|volume=38|issue=2|pages=77–93|doi=10.3161/068.038.0204|s2cid=52832425 |doi-access=free}}</ref> The maximum recorded age is 13.1 years,<ref name = anage>{{cite web|title=An Age entry for ''Passer montanus''|work=AnAge, the animal ageing and longevity database | url=http://genomics.senescence.info/species/entry.php?species=Passer_montanus |access-date=30 January 2009 }}</ref> but three years is a typical lifespan.<ref name =BTO/>

=== Temperature regulation ===
Eurasian tree sparrows exhibit various physiological adaptations to seasonal changes in temperature and photoperiod. When exposed to shorter photoperiods and colder temperatures in winter, Eurasian tree sparrows increased body mass, increased [[basal metabolic rate]], increased [[cytochrome c oxidase]] enzyme activity, and increased [[Thyroid hormones|thyroid hormone]] activity, with temperature having a greater effect than photoperiod.<ref>{{Cite journal |last1=Li |first1=Lin |last2=Ge |first2=Jingru |last3=Zheng |first3=Sangyu |last4=Hong |first4=Lihong |last5=Zhang |first5=Xini |last6=Li |first6=Ming |last7=Liu |first7=Jinsong |date=2020-01-01 |title=Thermogenic responses in Eurasian Tree Sparrow (Passer montanus) to seasonal acclimatization and temperature-photoperiod acclimation |journal=Avian Research |language=en |volume=11 |issue=1 |doi=10.1186/s40657-020-00222-9 |issn=2055-6187 |doi-access=free }}</ref> Increasing body mass allows these birds to store more energy, while their increased basal metabolic rate is due to a higher amount of energy needed to maintain their body temperature in colder conditions. Another study also found that during the winter, Eurasian tree sparrows also exhibited higher levels of thyroid hormone T3, which helps regulate the body’s use of energy.<ref>{{Cite journal |last1=Zheng |first1=Wei-Hong |last2=Li |first2=Ming |last3=Liu |first3=Jin-Song |last4=Shao |first4=Shu-Li |last5=Xu |first5=Xing-Jun |date=2014 |title=Seasonal variation of metabolic thermogenesis in Eurasian tree sparrows (Passer montanus) over a latitudinal gradient |url=https://pubmed.ncbi.nlm.nih.gov/25244382/ |journal=Physiological and Biochemical Zoology |volume=87 |issue=5 |pages=704–718 |doi=10.1086/676832 |issn=1537-5293 |pmid=25244382}}</ref> The birds’ increased T3 levels was correlated with increased heat production.

==Conservation status==
[[File:Stubble below Tinto.jpg|thumb|Winter stubble is a seasonal food resource.<ref name = europea/>]]
The Eurasian tree sparrow has a large range estimated as {{convert|98.3|sqkm|sqmi|disp=preunit|million }} and a population of 190–310&nbsp;million individuals. Although the population is declining, the species is not believed to approach the thresholds for the population decline criterion of the [[IUCN Red List]] (that is, declining more than 30% in 10 years or three generations). For these reasons, the species' [[conservation status]] is evaluated at the global level as being of [[Least Concern]].<ref name="iucn status 19 November 2021" />

Although the Eurasian tree sparrow has been expanding its range in [[Fennoscandia]] and eastern Europe, populations have been declining in much of western Europe,<ref name = BWP/><ref>{{cite book|author=BirdLife International|year=2004|title=Birds in Europe: population estimates, trends and conservation status|url=http://www.birdlife.org/action/science/species/birds_in_europe/index.html|location=Cambridge, England|publisher=BirdLife International|series=Conservation Series No. 12|chapter-url=http://www.birdlife.org/datazone/userfiles/file/Species/BirdsInEuropeII/BiE2004Sp8385.pdf|contribution=''Passer montanus'', Eurasian Tree Sparrow|access-date=2011-10-28|archive-date=2013-01-16|archive-url=https://web.archive.org/web/20130116172241/http://birdlife.org/action/science/species/birds_in_europe/index.html|url-status=dead}}</ref> a trend reflected in other farmland birds such as the [[skylark]], [[corn bunting]] and [[northern lapwing]]. From 1980 to 2003, common farmland bird numbers fell by 28%.<ref name = europea>{{cite web | title= Research highlights decline of farm and forest birds | date= 8 June 2005 | url= http://www.birdlife.org/news/news/2005/06/european_indicators.html | publisher= [[BirdLife International]] | access-date= 3 February 2009 | archive-date= 7 June 2007 | archive-url= https://web.archive.org/web/20070607155029/http://www.birdlife.org/news/news/2005/06/european_indicators.html | url-status= dead }}</ref> The collapse in populations seems to have been particularly severe in Great Britain, where there was a 95% decline between 1970 and 1998,<ref>{{cite web|title= Tree sparrow | work=Conservation case studies | url= http://www.rspb.org.uk/ourwork/conservation/species/casestudies/treesparrow.asp | publisher= [[Royal Society for the Protection of Birds]] |access-date=3 February 2009|archive-url=https://web.archive.org/web/20100115014620/http://www.rspb.org.uk/ourwork/conservation/species/casestudies/treesparrow.asp|archive-date=15 January 2010}}</ref> and Ireland, which had only 1,000–1,500 pairs in the late 1990s.<ref name=BWP/><ref>{{cite news| url=http://www.rte.ie/news/2012/0123/sparrow.html | work=RTÉ News | title=Tree sparrow on the increase on east coast | date=23 January 2012}}</ref> In the British Isles, such declines may be due to natural fluctuations, to which Eurasian tree sparrows are known to be prone.<ref name="Summers-Smith 1988 220"/> Breeding performance has improved substantially as population sizes have decreased, suggesting that decreases in productivity were not responsible for the decline and that survival was the critical factor.<ref>{{cite web|title = Tree Sparrow ''Passer montanus'' | work= Breeding Birds in the Wider Countryside | url= http://www.bto.org/birdtrends2006/wcrtresp.htm | publisher=[[British Trust for Ornithology]] |access-date=3 February 2009|archive-url=https://web.archive.org/web/20080227005542/http://www.bto.org/birdtrends2006/wcrtresp.htm|archive-date=27 February 2008 }}</ref> The large decline in Eurasian tree sparrow numbers is probably the result of agricultural intensification and specialisation, particularly the increased use of herbicides and a trend towards autumn-sown crops (at the expense of spring-sown crops that produce stubble fields in winter). The change from mixed to specialised farming and the increased use of insecticides has reduced the amount of insect food available for nestlings.<ref name = europea/>

==Relationships with humans==
[[File:Crioceris asparagi.jpg|thumb|A horticultural pest, the [[common asparagus beetle]] is a regular prey item]]
The Eurasian tree sparrow is seen as a pest in some areas. In Australia, it damages many cereal and fruit crops and spoils cereal crops, animal feed and stored grain with its droppings. [[Quarantine]] rules prohibit the transport of this species into Western Australia.<ref name = oz/>

In the 19th century, there were massive campaigns to catch and kill sparrows in several European countries, including France, Prussia, Hungary, Baden.<ref>[https://archive.today/20240519170123/https://www.theatlantic.com/magazine/archive/1868/05/the-european-house-sparrow/628410/ The European House-Sparrow]</ref>

The [[Paramount leader]] of China, [[Mao Zedong]] attempted in April 1958 to reduce crop damage by Eurasian tree sparrows, which was estimated to be {{convert|4.5|kg|lb|abbr=on}} of grain per bird each year, by mobilising millions of people and many scarecrows to drive the birds to death by exhaustion. Although successful at reducing the sparrow population, the "[[Four Pests campaign]]" overlooked the numbers of locusts and other insect pests consumed by the birds. Crop yields collapsed, exacerbating a famine that led to the deaths of 30&nbsp;million people between 1959 and 1961.<ref name= Cocker>{{Harvnb|Cocker|Mabey|2005|pp=442–443}}</ref><ref name= independent>{{cite news| first = Michael | last = McCarthy | title = The secret life of sparrows | newspaper =The Independent | url = https://www.independent.co.uk/environment/the-secret-life-of-sparrows-410252.html| archive-url = https://web.archive.org/web/20080506001314/http://www.independent.co.uk/environment/the-secret-life-of-sparrows-410252.html| url-status = dead| archive-date = May 6, 2008| date = 2 August 2006 | access-date =30 January 2009 | location=London}}</ref> The Eurasian tree sparrow's consumption of insects has led to its use in agriculture to control fruit tree pests and the [[common asparagus beetle]] (''Crioceris aspergi'').<ref>{{cite journal| last= Dix | first= M. E. | author2= Johnson, R. J. | author3= Harrell, M. O. | author4= Case, R. M. | author5= Wright R. J. | author6= Hodges, L. | author7= Brandle, J. R. | author8= Schoeneberger, M. M. | author9= Sunderman, N. J. | author10= Fitzmaurice, R. L.  | author11= Young, L. J. | author12= Hubbard, K. G. |date=March 1995| title= Influences of trees on abundance of natural enemies of insect pests: a review | journal= Agroforestry Systems| volume=29 | issue= 3| pages= 303–311|doi =10.1007/BF00704876| bibcode= 1995AgrSy..29..303D | s2cid= 6579059 | url= https://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1412&context=agronomyfacpub | url-access= subscription }}</ref>

The Eurasian tree sparrow has long been depicted in Chinese and Japanese art, often on a plant spray or in a flying flock,<ref name= independent/> and representations by oriental artists including [[Hiroshige]] have featured on the postage stamps of [[Antigua and Barbuda]], Central African Republic, China, and the Gambia. More straightforward illustrations were used on the stamps of Belarus, Belgium, Cambodia, Estonia, and Taiwan.<ref>{{cite web|title= Stamps showing Eurasian Tree Sparrow ''Passer montanus'' |url= http://www.birdtheme.org/mainlyimages/index.php?spec=2203| publisher= Birdtheme.org |access-date=18 February 2009 }}</ref> The fluttering of the bird gave rise to a traditional Japanese dance, the ''[[Japanese traditional dance#Nihon Buyō|Suzume Odori]]'', developed in [[Sendai]], which was depicted by artists such as [[Hokusai]].<ref>{{cite web| title= Sketches by Hokusai (''Hokusai Manga'') | work= Nipponia No. 27 |date=December 15, 2003 | url=http://web-japan.org/nipponia/nipponia27/en/feature/feature04.html |access-date=6 February 2009 }}</ref>

In the Philippines, where it is one of several species referred to as ''[[maya (bird)|maya]]'', and is sometimes specifically referred to as the "mayang simbahan" ("church maya" or "church sparrow"), the Eurasian tree sparrow is the most common bird in the cities. Many urban Filipinos confuse it with the former national bird of the Philippines, the [[black-headed munia]] –  also called a ''maya'', but specifically differentiated in [[Folk taxonomy|folk taxa]] as the "mayang pula" ("red maya").<ref>{{cite news|url=http://newsinfo.inquirer.net/breakingnews/regions/view_article.php?article_id=77631 |title=2 Philippine eagles spotted in Leyte forest |last=Labro |first=Vicente |date=19 July 2007 |newspaper=[[Philippine Daily Inquirer]] |access-date=21 November 2008 |archive-date=25 May 2024 |archive-url=https://archive.today/20240525234159/https://www.webcitation.org/67XrmQfv1?url=http://www.inquirer.net/specialfeatures/theenvironmentreport/view.php%3Fdb=1&article=20070719-77631 |url-status=dead }}</ref>

<gallery class="center" caption="In popular culture" widths="200px" heights="130px">
File:Suzume Odori.jpg|Detail from [[Hokusai|Hokusai's]] ''Suzume Odori'', depicting the [[Japanese traditional dance]] inspired by sparrows
File:Huang-Quan Tree sparrow.jpg|Part of an ink on silk painting by [[Huang Quan (painter)|Huang Quan]] {{circa|965 CE}} showing a fledgling soliciting food from an adult
</gallery>

==References==
{{Reflist}}

=== Works cited ===<!-- {{cite journal|journal=Field Museum of Natural History Publication, Zoological Series |volume=18|issue=11|pages=343–379|url=https://www.biodiversitylibrary.org/page/2826634|title=Birds of Western China Obtained by the Kelly–Roosevelt Expedition|first=Outram|last=Bangs|date=12 October 1932}} -->
* {{cite book |last=Anderson |first=Ted R. |title=Biology of the Ubiquitous House Sparrow: From Genes to Populations |year=2006 |publisher=Oxford University Press |isbn =978-0-19-530411-4 }}
* {{cite book |last=Arlott |first=Norman | title=Birds of the Palearctic: Passerines |publisher=Collins |year=2007 |location=London |isbn = 978-0-00-714705-2 }}
* {{cite book|last=Brisson |first=Mathurin Jacques |title=Ornithologie ou méthode contenant la division des oiseaux en ordres, sections, genres, especes & leurs variétés. A laquelle on a joint une description exacte de chaque espece, avec les citations des auteurs qui en ont traité, les noms qu'ils leur ont donnés, ceux que leur ont donnés les différentes nations, & les noms vulgaires. Ouvrage enrichi de figures en taille-douce |year=1760 |location=Paris |publisher=Bauche |language=fr}}
* {{cite book |last1=Byers |first1=Clive |last2=Curson |first2=Jon|first3=Urban |last3=Olsson |title=Sparrows and Buntings: a Guide to the Sparrows and Buntings of North America and the World |year=1995 |publisher=Pica Press |isbn=978-1-873403-19-8}}
* {{cite book |last1=Clement |first1=Peter |last2=Harris |first2=Alan |last3=Davis |first3=John |title=Finches and Sparrows: an Identification Guide |year=1993 |publisher=Christopher Helm |isbn=978-0-7136-8017-1}}
* {{cite book |last1=Cocker |first1=Mark |last2=Mabey |first2=Richard |title=Birds Britannica |year=2005 |location=London |publisher=Chatto & Windus |isbn=978-0-7011-6907-7}}
* {{cite book |last1=Coward |first1=Thomas Alfred |title =The Birds of the British Isles and Their Eggs |volume=I |edition=3rd |year=1930 |publisher=Frederick Warne |isbn=978-0-7232-0999-7}}
* {{cite book |last=Forbush |first=Edward Howe |url=https://archive.org/details/usefulbirdstheir00forbiala |title=Useful Birds and Their Protection |year=1907 |location=Boston |publisher=Massachusetts State Board of Agriculture }}
* {{cite book |last1=Kennedy |first1=Robert S. |last2=Gonzales |first2=Pedro C. |last3=Dickinson |first3=Edward C. |author-link3=Edward C. Dickinson|last4=Miranda |first4=Hector |last5=Fisher |first5=Timothy H. |title=A Guide to the Birds of the Philippines |publisher=Oxford University Press |isbn= 978-0-19-854668-9 |year=2000}}
* {{cite book |last=Linnaeus |first=Carolus |author-link=Carl Linnaeus |title=Systema naturae per regna tria naturae, secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis. Tomus I. Editio decima, reformata |location=Holmia|publisher=Laurentius Salvius |year=1758 |language=la|title-link=10th edition of Systema Naturae }}
* {{cite book |last1 = Mullarney |first1 = Killian |last2=Svensson |first2=Lars |last3=Zetterstrom |first3=Dan |last4=Grant |first4=Peter |title=Collins Bird Guide |year=1999 |location=London |publisher =HarperCollins |isbn = 978-0-00-219728-1|title-link = Collins Bird Guide }}
* {{cite book |last1=Pinowski |first1=Jan |last2=Kavanagh |first2=P. P. |last3=Górski |first3=W. |title=Nestling mortality of granivorous birds due to microorganisms and toxic substances |year=1991 |publisher=Polish Scientific Publishers |location=Varsovia |isbn=978-83-01-10476-4}}
* {{cite book |editor1-last=Pinowski |editor1-first=Jan |editor2-last=Summers-Smith |editor2-first=J. Denis | title = Granivorous birds in the agricultural landscape |year=1990 |publisher=Polish Academy of Sciences |location=Lomianki |isbn =978-83-01-08460-8 }}
* {{cite book |last1=Rasmussen |first1=Pamela C. |author-link=Pamela C. Rasmussen |last2=Anderton |first2=John C. |author-link2=John C. Anderton |year=2005 |title=Birds of South Asia: The Ripley Guide |publisher=[[Smithsonian Institution]] Press and [[Lynx Edicions]] |location=Washington |isbn=978-84-87334-67-2|title-link=Birds of South Asia: The Ripley Guide }}
* {{cite book |last1=Robinson |first1=Herbert C. |last2=Chasen |first2=Frederick Nutter |title=Birds of the Malay Peninsula |year=1927–1939 |publisher=H. F. & G. Witherby |location=London |url=http://rmbr.nus.edu.sg/biblio/robinson_chasen/ |url-status=dead |archive-url=https://web.archive.org/web/20090201062009/http://rmbr.nus.edu.sg/biblio/robinson_chasen/ |archive-date=2009-02-01 }}
* {{cite book |editor-last1=Snow |editor-first1=David |editor-last2=Perrins |editor-first2=Christopher M. |title=The Birds of the Western Palearctic |edition=concise |volume=I-II |publisher=Oxford University Press |year=1998 |location=New York |isbn = 978-0-19-854099-1 |title-link=The Birds of the Western Palearctic }}
* {{cite book |last=Summers-Smith |author-link=J. Denis Summers-Smith |first=J. Denis |title=The Sparrows |publisher=T. & A. D. Poyser |year=1988 |location=Calton, Staffs, England |isbn=978-0-85661-048-6 |others=illustrated by [[Robert Gillmor]] |url-access=registration |url=https://archive.org/details/sparrowsstudyofg0000summ }}

===Further reading===
* {{cite book |title=The Tree Sparrow |first=J. Denis |last=Summers-Smith |author-link=J. Denis Summers-Smith |others=Illustrated by [[Robert Gillmor|Gillmor, Robert]] |publisher=J. Denis Summers-Smith |date=January 1995 |isbn=978-0952538301}}

== External links ==
{{Wikispecies|Passer montanus}}
{{Commons category|Passer montanus}}
{{EB1911 poster|Sparrow}}<!-- one section is specially about this species -->
* [https://web.archive.org/web/20080605225239/http://www.arkive.org/species/ARK/birds/Passer_montanus/ Photographs and video] on [[ARKive]]
* [http://www.skullsite.com/completelist/speciesinfo.cfm?spec=255 Skull image] {{Webarchive|url=https://web.archive.org/web/20071110124032/http://www.skullsite.com/completelist/speciesinfo.cfm?spec=255 |date=2007-11-10 }}
* [https://web.archive.org/web/20141202065932/http://aulaenred.ibercaja.es/wp-content/uploads/421_TreeSparrowP.montanus.pdf Ageing and sexing] (PDF) by Javier Blasco-Zumeta & Gerd-Michael Heinze
* [http://ibc.lynxeds.com/species/eurasian-tree-sparrow-passer-montanus Tree sparrow videos, photos & sounds] on the Internet Bird Collection
* [http://www.ornithos.de/Ornithos/Feather_Collection/Passer_montanus/Passer_montanus.htm Feathers of the Eurasian tree sparrow] {{Webarchive|url=https://web.archive.org/web/20150924061910/http://www.ornithos.de/Ornithos/Feather_Collection/Passer_montanus/Passer_montanus.htm |date=2015-09-24 }}
* [https://sites.google.com/site/intlsocfortaxonomicexplratins/home/documenting-passer-montanus-nest-eggs-hatchlings-that-are-about-to-fledge Documenting Passer montanus' nest, eggs, hatchlings, nestlings and fledglings] by Isidro A.T. Savillo

{{Passeridae}}
{{Taxonbar|from=Q25968}}
{{Authority control}}

[[Category:Passer]]
[[Category:Birds of Eurasia]]
[[Category:Birds of Japan]]
[[Category:Birds of Yunnan]]
[[Category:Birds described in 1758|Eurasian tree sparrow]]
[[Category:Taxa named by Carl Linnaeus|Eurasian tree sparrow]]