Editing Tytonidae (section)

==Behaviour and ecology==

===Hunting and feeding===
Hunting [[Crepuscular animal|in twilight]] or [[Nocturnality|at night]], the barn owl can target its prey and dive to the ground. Its legs and toes are long and slender, which improves its ability to forage among dense foliage or beneath the snow and gives it a wide spread of talons when attacking prey. This bird hunts by flying slowly, quartering the ground and hovering over spots that may conceal prey. It has long, broad wings that enable it to manoeuvre and turn abruptly.<ref name=Taylor46/> It has acute hearing, with ears placed asymmetrically, which improves detection of sound position and distance; the bird does not require sight to hunt. The facial disc helps with the bird's hearing, as is shown by the fact that, with the ruff feathers removed, the bird can still determine a sound source's [[azimuth|direction]], although without the disc it cannot determine the source's [[elevation|height]].<ref>{{cite journal |author1=Knudsen, Eric I. |author2=Konishi, Masakazu |year=1979 |title=Mechanisms of sound localization in the barn owl (''Tyto alba'') |journal=Journal of Comparative Physiology |volume=133 |issue=1 |pages=13–21 |doi=10.1007/BF00663106 |s2cid=1502927 }}</ref> It may perch on branches, fence posts, or other lookouts to scan its surroundings, and this is the main means of prey location in the [[Elaeis guineensis|oil palm]] plantations of Malaysia.<ref name=Taylor61>Taylor (2004) pp. 47–61</ref><ref name="ArdeaMayrom2009">{{cite journal |author1=Meyrom, Kobi |author2=Motro, Yoav |author3=Leshem, Yossi |author4=Aviel, Shaul |author5=Izhaki, Ido |author6=Argyle, Francis |author7=Charter, Motti |year=2009 |title=Nest-box use by the barn owl ''Tyto alba'' in a biological pest control program in the Beit She'an Valley, Israel |journal=Ardea |volume=97 |issue=4 |pages=463–467 |doi=10.5253/078.097.0410 |s2cid=86309543 |doi-access=free }}</ref>

[[File:Chouette crâne (2).jpg|thumb|right|Skull, showing the powerful beak]]

Rodents and other small mammals may constitute over ninety percent of the prey caught.<ref name=Taylor46/><ref name="Lavariega">{{cite journal | last1 = Lavariega | first1 = Mario C. | last2 = García-Meza | first2 = Josué | last3 = Martínez-Ayón | first3=Yazmín del Mar | last4 = Camarillo-Chávez | first4 = David | last5 = Hernández-Velasco | first5 = Teresa | last6 = Briones-Salas | first6 = Miguel | title = Análisis de las presas de la Lechuza de Campanario (Tytonidae) en Oaxaca Central, México | journal = Neotropical Biology and Conservation | volume = 11 | issue = 1 | year = 2015 | issn = 2236-3777 | doi = 10.4013/nbc.2016.111.03 | url = http://revistas.unisinos.br/index.php/neotropical/article/view/nbc.2016.111.03 | language = es| doi-access = free | bibcode = 2015NeoBC..1111.03L }}{{Open access}}</ref><ref>{{cite journal|author=Ingles, Chuck |year=1995 |title=Summary of California studies analyzing the diet of barn owls |journal=Sustainable Agriculture/Technical Reviews |volume=2 |pages=14–16 |url=http://www.sarep.ucdavis.edu/newsltr/v7n2/sa-9.htm |url-status=dead |archive-url=https://web.archive.org/web/20111128004146/http://www.sarep.ucdavis.edu/newsltr/v7n2/sa-9.htm |archive-date=November 28, 2011 }}</ref> Birds are also taken, as well as [[lizard]]s, [[amphibian]]s, [[fish]], [[spider]]s, and [[insect]]s.<ref>{{cite web | url=https://www.peregrinefund.org/explore-raptors-species/owls/barn-owl | title=Barn Owl &#124; the Peregrine Fund }}</ref><ref>König, Claus, Friedhelm Weick, and Jan-Hendrik Becking. Owls of the World. 2nd ed. Bloomsbury Publishing, 2009. Web. 23 May. 2023.</ref> Even when they are plentiful, and other prey scarce, [[earthworm]]s do not seem to be consumed. In North America and most of Europe, [[vole]]s predominate in the diet, and [[shrew]]s are the second most common food choice.<ref name=Taylor46>Taylor (2004) pp. 29–46</ref> In Ireland, the accidental introduction of the [[bank vole]] in the 1950s led to a major shift in the barn owl's diet: where their ranges overlap, the vole is now by far the largest prey item.<ref>{{cite journal |author1=Kelleher, K. M. |author2=Oliver, G. A. |author3=Sleeman, D. P. |year=2010 |title=The composition and sex of rodent prey taken by Barn Owls ''Tyto alba'' at a roost in County Cork |journal=Irish Birds |volume=9 |pages=35–40 |issn=0332-0111 }}</ref> [[Mice]] and [[rat]]s are the main foodstuffs in the Mediterranean region, the tropics, subtropics, and Australia. [[Gopher]]s, [[muskrat]]s, [[hare]]s, [[rabbit]]s, and [[bat]]s are also preyed upon.<ref>{{cite web|url=https://sta.uwi.edu/fst/lifesciences/sites/default/files/lifesciences/documents/ogatt/Tyto_alba%20-%20Barn%20Owl.pdf|title=Barn owl (Tyto alba)|website=Sta.uwi.edu|access-date=2022-04-09}}</ref><ref>{{cite web | url=https://animaldiversity.org/accounts/Tyto_alba/ | title=Tyto alba (Barn owl) | website=[[Animal Diversity Web]] }}</ref> Barn owls are usually specialist feeders in productive areas and generalists in areas where prey is scarce.<ref name=Taylor46/>

On the Cape Verde Islands, geckos are the mainstay of the diet, supplemented by birds such as [[plover]]s, [[godwit]]s, [[turnstone]]s, [[Ploceidae|weavers]], and [[pratincole]]s.<ref>{{cite journal |last=de Naurois | first=R. |year=1982 |title=Le statut de la Chouette effraie de l'archipel du Cape Verte ''Tyto alba detorta'' |journal=Rivista Italiana di Ornitologia |volume=52 | issue=3–4 |pages=154–166 | language=fr }}</ref> On a rocky islet off the coast of California, a clutch of four young were being reared on a diet of [[Leach's storm petrel]] (''Oceanodroma leucorhoa'').<ref>{{cite journal | last=Bonnot | first=Paul | year=1928 | title=An outlaw Barn Owl | journal=Condor | volume=30 | issue=5 | pages=320–329 | jstor=1363231 | url=http://sora.unm.edu/sites/default/files/journals/condor/v030n05/p0320-p0320.pdf | doi = 10.2307/1363231 }}</ref> On bird-rich islands, a barn owl might include birds as some fifteen to twenty percent of its diet, while in grassland it will gorge itself on swarming termites, or on Orthoptera such as Copiphorinae katydids, Jerusalem crickets (Stenopelmatidae), or true crickets (Gryllidae). Smaller prey is usually torn into chunks and eaten completely, including bones and fur, while prey larger than about {{convert|100|g}}—such as baby rabbits, ''[[Cryptomys]]'' [[blesmol]]s, or ''[[Otomys]]'' vlei rats—is usually dismembered and the inedible parts discarded.<ref name = tp67>{{cite journal | last1=Traylor | first1=Melvin A. | last2=Parelius | first2=Daniel | year=1967 | title=A collection of birds from the Ivory Coast | journal=Fieldiana Zoology | volume=51 | issue=7 | pages=91–117 | url=https://archive.org/details/collectionofbird517tray}}</ref><ref name="Ehrlich et al 1994 250 254">Ehrlich et al. (1994) pp. 250–254</ref><ref name=Laudet>{{cite journal |author1=Laudet, Frédéric |author2=Denys, Christiane |author3=Senegas, Frank |year=2002 |title=Owls, multirejection and completeness of prey remains: implications for small mammal taphonomy |journal=Acta Zoologica Cracoviensia |volume=45 |pages=341–355 |url=http://www.isez.pan.krakow.pl/journals/azc_v/pdf/45/27.pdf }}</ref>

Compared to other owls of similar size, the barn owl has a much higher [[Metabolism|metabolic rate]], requiring relatively more food. Relative to its size, barn owls consume more rodents. Studies have shown that an individual barn owl may eat one or more voles (or their equivalent) per night, equivalent to about fourteen percent of the bird's bodyweight. Excess food is often [[Hoarding (animal behavior)|cached]] at roosting sites and can be used when food is scarce.<ref name=Taylor95>Taylor (2004) pp. 91–95</ref> This makes the barn owl one of the most economically valuable wildlife animals for agriculture. Farmers often find these owls more effective than poison in keeping down rodent pests, and they can encourage barn owl habitation by providing nesting sites.<ref name="ArdeaMayrom2009" />

===Breeding===

Barn owls living in tropical regions can breed at any time of year, but some seasonality in nesting is still evident. Where there are distinct wet and dry seasons, egg-laying usually takes place during the dry season, with increased rodent prey becoming available to the birds as the vegetation dies off. In arid regions, such as parts of Australia, breeding may be irregular and may happen in wet periods, with the resultant temporary increase in the populations of small mammals. In [[temperate climate]]s, nesting seasons become more distinct, and there are some seasons of the year when no egg-laying takes place. In Europe and North America, most nesting takes place between March and June, when temperatures are increasing. The actual dates of egg-laying vary by year and by location, being correlated with the amount of prey-rich foraging habitat around the nest site.<ref name=Taylor135>Taylor (2004) pp. 121–135</ref> An increase in rodent populations will usually stimulate the local barn owls to begin nesting, and, consequently, two broods are often raised in a good year, even in the cooler parts of the owl's range.<ref name=BTO>{{cite web |url=http://blx1.bto.org/birdfacts/results/bob7350.htm |title=Barn Owl ''Tyto alba'' (Scopoli, 1769) |year=2009 |publisher=British Trust for Ornithology |access-date=2014-09-08}}</ref>

===Moulting===
[[File:Owlets.jpg|thumb|right|Brood prior to [[Fledge|fledging]], beginning to shed their nestling [[down feather|down]]]]
Feathers become abraded over time and all birds need to replace them at intervals. Barn owls are particularly dependent on their ability to fly quietly and manoeuvre efficiently. In temperate areas, the owls undergo a prolonged [[Moulting|moult]] that lasts through three phases over a period of two years. The female starts to moult while incubating the eggs and brooding the chicks, a time when the male feeds her, so she does not need to fly much. The first [[primary feather]] to be shed is a central one, number 6, and it has regrown completely by the time the female resumes hunting. Feathers 4, 5, 7, and 8 are dropped at a similar time the following year and feathers 1, 2, 3, 9 and 10 in the bird's third year of adulthood. The secondary and tail feathers are lost and replaced over a similar timescale, again starting while incubation is taking place. In the case of the tail, the two outermost tail feathers are first shed, followed by the two central ones, the other tail feathers being shed the following year.<ref name=Shawyer90>Shawyer (1994) pp. 88–90</ref>

The male owl moults rather later in the year than the female, at a time when there is an abundance of food, the female has recommenced hunting, and the demands of the chicks are lessening. Unmated males without family responsibilities often start losing feathers earlier in the year. Their moult follows a pattern similarly prolonged as that of the female. The first sign that the male is moulting is often when a tail feather has been dropped at the roost.<ref name=Shawyer90/> A consequence of moulting is the loss of thermal insulation. This is of little importance in the tropics, and barn owls there usually moult a complete complement of flight feathers annually. The hot-climate moult may still take place over a long period but is usually concentrated at a particular time of year outside the breeding season.<ref name=Taylor120>Taylor (2004) pp. 108–120</ref>

===Predators and parasites===
[[File:Tyto alba -USA -three hissing and clicking-8.ogv|right|thumb|Three barn owl chicks threatening an intruder]]

[[Predator]]s of the barn owl include [[large American opossum]]s (''Didelphis''), the [[common raccoon]], and similar carnivorous [[mammal]]s, as well as [[eagle]]s, larger [[hawk]]s, and other owls. Among the latter, the [[great horned owl]] (''Bubo virginianus''), in the Americas, and the [[Eurasian eagle-owl]] (''B. bubo'') are noted predators of barn owls. Despite some sources claiming that there is little evidence of predation by great horned owls, one study from [[Washington (state)|Washington]] found that 10.9% of the local great horned owl's diet was made up of barn owls.<ref name=BNA>Marti, Carl D.; Poole, Alan F.; Bevier, L. R. (2005): "Barn Owl (''Tyto alba'')" ''The Birds of North America Online'' (A. Poole, Ed.). Ithaca: Cornell Lab of Ornithology; [http://bna.birds.cornell.edu/bna/species/001 Barn owl]</ref><ref>{{cite journal|doi=10.2307/1368658 |jstor=1368658 |last1=Millsap |first1=Brian A. |last2=Millsap |first2=Patricia A. |title=Burrow Nesting by Common Barn-Owls in North Central Colorado |journal=The Condor |year=1987 |volume=89 |issue=3 |pages=668–670 }}</ref><ref name= Knight>{{cite journal | last1 = Knight | first1 = R. L. | last2 = Jackman | first2 = R. E. | year = 1984 | title = Food-niche relationships between Great Horned Owls and Common Barn-Owls in eastern Washington | journal = Auk | volume = 101 | pages = 175–179 | doi = 10.1093/auk/101.1.175 }}</ref> In Africa, the principal predators of barn owls are [[Verreaux's eagle-owl]]s (''Bubo lacteus'') and [[Cape eagle-owl]]s (''B. capensis'').<ref name= Steyn>Steyn, P. (1983). ''Birds of prey of southern Africa: Their identification and life histories''. Croom Helm, Beckenham (UK). 1983.</ref><ref name= Brown>{{cite journal | last1 = Brown | first1 = L. H. | year = 1965 | title = Observations on Verreaux's Eagle Owl Bubo lacteus (Temminck) in Kenya | journal = Journal of the East African Natural History Society | volume = 25 | pages = 101–107 }}</ref> In Europe, although less dangerous than the eagle-owls, the chief diurnal predators are the [[northern goshawk]] (''Accipiter gentilis'') and the [[common buzzard]] (''Buteo buteo''). About 12 other large diurnal raptors and owls have also been reported as predators of barn owls, ranging from the similar-sized [[Cooper's hawk]] (''Accipiter cooperii'') and scarcely larger [[tawny owl]] (''Strix aluco'') to huge [[bald eagle|bald]] (''Haliaeetus leucocephalus'') and [[golden eagle]]s (''Aquila chrysaetos'').<ref name= Voous>Voous, K.H. 1988. ''Owls of the Northern Hemisphere''. The MIT Press, 0262220350.</ref> As a result of improved conservation measures, the populations of the northern goshawk and eagle-owls are increasing, thus increasing the incidence of hunting on barn owls where the species coexist.<ref name=Martin>{{cite web |url=http://britishbirds.co.uk/article/the-daylight-activity-of-barn-owls/ |title=The daylight activity of barn owls |author=Martin, Jeff |date=2013-07-08 |work=BritishBirds |publisher=BritishBirds Rarities Committee |access-date=2014-07-19 |archive-date=2016-09-09 |archive-url=https://web.archive.org/web/20160909231900/http://britishbirds.co.uk/article/the-daylight-activity-of-barn-owls/ |url-status=dead }}</ref>

When disturbed at its roosting site, an angry barn owl lowers its head and sways it from side to side, or the head may be lowered and stretched forward and the wings outstretched and drooped while the bird emits hisses and makes snapping noises with its beak. Another defensive attitude involves lying flat on the ground or crouching with wings spread out.<ref name=Witherby1943>Witherby (1943) pp. 343–347</ref>

Barn owls are hosts to a wide range of parasites. Fleas are present at nesting sites, and externally the birds are attacked by [[Bird louse|feather lice]] and [[feather mite]]s, which chew the barbules of the feathers and which are transferred from bird to bird by direct contact. Blood-sucking flies, such as ''Ornithomyia avicularia'', are often present, moving about among the plumage. Internal parasites include the [[Trematoda|fluke]] ''Strigea strigis'', the [[tapeworm]] ''Paruternia candelabraria'', several species of parasitic round worm, and [[Acanthocephala|spiny-headed worms]] in the genus ''[[Centrorhynchidae|Centrorhynchus]]''. These gut parasites are acquired when the birds feed on infected prey.<ref name="BunnWarburton2010">{{cite book|author1=Bunn, D. S. |author2=Warburton, A. B. |author3=Wilson, R. D. S.|title=The Barn Owl|url=https://books.google.com/books?id=TF-zE_vOu9sC&pg=PA177 |year=2010 |publisher=Bloomsbury Publishing |isbn=978-1-4081-3961-5 |page=177}}</ref> There is some indication that female birds with more and larger spots have a greater resistance to external parasites. This is correlated with smaller [[bursa of Fabricius]], glands associated with antibody production, and a lower fecundity of the blood-sucking fly ''[[Carnus hemapterus]]'', which attacks nestlings.<ref>{{cite journal |author1=Roulin, Alexandre |author2=Riols, Christian |author3=Dijkstra, Cor |author4=Ducrest, Anne-Lyse |year=2001 |title=Female plumage spottiness signals parasite resistance in the barn owl (''Tyto alba'')  |journal=Behavioral Ecology |volume=12 |issue=1 |pages=103–110 |doi=10.1093/oxfordjournals.beheco.a000371|doi-access=free }}</ref>

===Lifespan===
Collision with road vehicles is another cause of death and may result when birds forage on mown [[Road verge|verges]]. Some of these birds are in poor condition and may have been less able to evade oncoming vehicles than fit individuals. In some locations, road mortality rates can be particularly high, with collision rates being influenced by higher commercial traffic, roadside verges that are grass rather than shrubs, and where small mammals are abundant.<ref>{{cite journal | author1= Arnold, E.M. |author2= Hanser, S.E. | author3= Regan, T. | author4= Thompson, J. | author5= Lowe, M. |author6= Kociolek, A. | author7= Belthoff, J.R. |   year=2019| title= Spatial, road geometric and biotic factors associated with Barn Owl mortality along an interstate highway | journal=Ibis| volume=161| pages = 147–161 | doi= 10.1111/ibi.12593| issue=2| doi-access= free |bibcode= 2019Ibis..161..147A }}</ref> Historically, many deaths were caused by the use of [[pesticide]]s, and this may still be the case in some parts of the world. Collisions with power-lines kill some birds, and being shot accounts for others, especially in Mediterranean regions.<ref name=Taylor215>Taylor (2004) pp. 203–215</ref>