Editing Australian zebra finch (section)

===Breeding===
[[File:Taeniopygia guttata -Blue Mountains, New South Wales, Australia-8.jpg|thumb|Female with two juveniles in New South Wales, Australia]]
[[Image:Zebrafinchchicks.jpg|thumb|Juvenile zebra finches]]
The Australian zebra finch generally breeds in loose colonies of up to 50 nests (although the number of individuals in a colony can be up to about 230 when breeding, and around 350 when not), but it may nest solitarily. It usually places its nest in a thorny shrub poor tree, although it will nest in other structures, natural and artificial.<ref name="Zann27"/> Often, there are multiple nests in one shrub.<ref name="hbwc"/>

In non-arid parts of Australia, colonies are often occupied year-round.<ref name="Zann78">{{harvnb|Zann|1996|p=78}}</ref> During cold days in the non-breeding season, members of these colonies usually feed in flocks for about two hours, breaking up into small groups to rest, preen, sing, and court before foraging again in a large flock until about one hour before sunset, when they return to the colony. On warmer days, some of the small groups return to the colony to build nests and perform their normal activities. During the breeding season, finches finding or building a nest often return after about an hour of feeding, and on cold days they are joined by those incubating or brooding young. Pairs that have not yet laid their eggs sometimes elect to court and mate in special "courting trees" before joining the flock. In the afternoon, most pairs engage in social activities, which often take place at "social trees".<ref name="Zann81–82">{{harvnb|Zann|1996|pp=81–82}}</ref> The zebra finch frequently does not breed where it was born; of the ringed birds that bred in the Danaher breeding colony ({{Coord|36|09|S|145|26|E}}) from 1985 to 1989, 24% of them were hatched from the colony or in the immediate vicinity. This [[Biological dispersal|natal dispersal]] is not sex-biased, unlike in most passerines. However, males between 36 and 50 days of age are more likely to disperse than females, although after this age, more females disperse than males.<ref name="ZannRunciman2008"/> Predation is likely a major factor in coloniality; nests in the main colony suffer less predation than nests further away. Pairs with preyed-upon nests are significantly more likely to nest in a bush more than {{convert|20|m|ft}} away from their previous nesting plant.<ref name="Zann76">{{harvnb|Zann|1996|p=76}}</ref> Another large factor is where others nest: individuals are more likely to nest closer to conspecifics. In addition, reproductive success of conspecifics may play a role in where individuals nest; a study published in 2012 found that this finch was more likely to breed near nests with chicks older than six days (used as a proxy for reproductive success because they fledge about 87% of the time).<ref name="MarietteGriffith2012">{{cite journal|last1=Mariette|first1=Mylene M.|last2=Griffith|first2=Simon C.|title=Conspecific attraction and nest site selection in a nomadic species, the zebra finch|journal=Oikos|volume=121|issue=6|year=2012|pages=823–834|issn=0030-1299|doi=10.1111/j.1600-0706.2011.20014.x|bibcode=2012Oikos.121..823M }}</ref>

The Australian zebra finch builds both a roosting and breeding nest. The former is dome-shaped, has a large entrance on the side, and lacks an entrance tunnel.<ref name="Kikkawa1980">{{cite journal|last1=Kikkawa|first1=Jiro|title=Seasonality of nesting by zebra finches at Armidale, NSW|journal=Emu - Austral Ornithology|volume=80|issue=1|year=1980|pages=13–20|issn=0158-4197|doi=10.1071/MU9800013|bibcode=1980EmuAO..80...13K }}</ref> This nest helps the zebra finch conserve body heat (likely through its roof and walls and by allowing birds to huddle together): an individual in a roosting nest saves about 18% of the energy of one outside.<ref name="Zann81">{{harvnb|Zann|1996|p=81}}</ref> The breeding nest (which generally ranges from about {{convert|12|to|24|cm|in}} in length<ref name="Zann87"/>) has a small entrance<ref name="Kikkawa1980"/> followed by a tunnel about {{convert|3|to|5|cm|in|spell=in}} in diameter and up to {{convert|8|cm|in|spell=in}} in length, which conceals the contents of the nest, leading to the egg chamber, which has (from the outside) a diameter of {{convert|12|to|20|cm|in}}; the latter two are separated by a raised lip, preventing eggs from rolling out. This chamber often sits on an old nest; otherwise, a foundation consisting of many short, stiff stems over horizontal branches is constructed. The walls of the nest range in thickness from {{convert|1|to|3|cm|in|spell=in}}, with an outer layer of longer stiff and rough grass stems and an inner layer of shorter soft and fine stems. The egg chamber is also lined with soft material, such as wool and feathers.<ref name="Zann87">{{harvnb|Zann|1996|p=87}}</ref> Both sites are defended during the day; but while a desperate bird is sometimes let in to the roosting nest during the night, the breeding nest is always guarded.<ref name="Zann73">{{harvnb|Zann|1996|p=73}}</ref>

The Australian zebra finch is an [[opportunistic breeder]], initiating reproductive behaviour about one to three months after water becomes available. This is so that the young hatch when semi-ripe and ripe seeds (their primary food) become available. This finding is in line with the food quality hypothesis of zebra finch breeding, which states that dry grass seed is inadequate as a food source for nestlings, and that higher quality food (like ripening seeds) is needed to sustain them.<ref name="ZannMorton1995">{{cite journal|last1=Zann|first1=Richard A.|last2=Morton|first2=Stephen R.|last3=Jones|first3=Kevin R.|last4=Burley|first4=Nancy T.|title=The timing of breeding by zebra finches in relation to rainfall in central Australia|journal=Emu - Austral Ornithology|volume=95|issue=3|year=1995|pages=208–222|issn=0158-4197|doi=10.1071/MU9950208|bibcode=1995EmuAO..95..208Z }}</ref> Thus, in captivity, it can breed year round when provided with sufficient water,<ref name="Hauber2014"/> and it may attempt to breed several times per breeding season.<ref name="SchielzethBolund2010">{{cite journal|last1=Schielzeth|first1=Holger|last2=Bolund|first2=Elisabeth|title=Patterns of conspecific brood parasitism in zebra finches|journal=Animal Behaviour|volume=79|issue=6|year=2010|pages=1329–1337|issn=0003-3472|doi=10.1016/j.anbehav.2010.03.006|s2cid=53171704}}</ref> Zebra finches are socially monogamous, with pair bonds lasting until the death of one of the partners, after which the widowed bird re-pairs.<ref name="Zann84–85"/> [[Extra-pair copulation]], mating with individuals other than one's mate, occurs occasionally, with females usually soliciting it.<ref name="Houtman1992">{{cite journal |last1= Houtman |first1=Anne M. |date=22 July 1992 |title=Female Zebra Finches Choose Extra-Pair Copulations with Genetically Attractive Males |journal=Proceedings of the Royal Society B |volume=249 |issue=1324 |pages=3–6 |doi=10.1098/rspb.1992.0075 |s2cid=83985353 }}</ref> Extra-pair parentage is relatively rare in the wild, accounting for about 2% of young.<ref name="GriffithHolleley2010">{{cite journal|last1=Griffith|first1=Simon C.|last2=Holleley|first2=Clare E.|last3=Mariette|first3=Mylene M.|last4=Pryke|first4=Sarah R.|author-link4=Sarah Pryke|last5=Svedin|first5=Nina|year=2010|title=Low level of extrapair parentage in wild zebra finches|journal=Animal Behaviour|volume=79|issue=2|pages=261–264|doi=10.1016/j.anbehav.2009.11.031|s2cid=53170552|issn=0003-3472}}</ref><ref name="BirkheadBurke1990">{{cite journal|last1=Birkhead|first1=T. R.|last2=Burke|first2=T.|last3=Zann|first3=R.|last4=Hunter|first4=F. M.|last5=Krupa|first5=A. P.|title=Extra-pair paternity and intraspecific brood parasitism in wild zebra finches ''Taeniopygia guttata'', revealed by DNA fingerprinting|journal=Behavioral Ecology and Sociobiology|volume=27|issue=5|year=1990|pages=315–324|issn=0340-5443|doi=10.1007/BF00164002|bibcode=1990BEcoS..27..315B |s2cid=12744714}}</ref> Attempts at forced extra-pair copulations by males occur frequently (about 43.8% of the time in one study); but, females can always successfully resist forced copulations if they so choose.<ref name="Forstmeier2007"/>

<!--Paragraph below dedicated to explaining evolution of EPC-->
There are multiple hypotheses as to why extra-pair copulation might have evolved.<ref name="ForstmeierMartin2011">{{cite journal|last1=Forstmeier|first1=W.|last2=Martin|first2=K.|last3=Bolund|first3=E.|last4=Schielzeth|first4=H.|last5=Kempenaers|first5=B.|title=Female extrapair mating behavior can evolve via indirect selection on males|journal=Proceedings of the National Academy of Sciences|volume=108|issue=26|year=2011|pages=10608–10613|issn=0027-8424|doi=10.1073/pnas.1103195108|pmid=21670288|pmc=3127899|doi-access=free}}</ref> One theory is the good genes theory, which states that a female chooses extra-pair copulation if the extra-pair male grants its offspring direct benefits as a result of the male's alleles.<ref name="ForstmeierNakagawa2014">{{cite journal|last1=Forstmeier|first1=Wolfgang|last2=Nakagawa|first2=Shinichi|last3=Griffith|first3=Simon C.|last4=Kempenaers|first4=Bart|title=Female extra-pair mating: adaptation or genetic constraint?|journal=Trends in Ecology & Evolution|volume=29|issue=8|year=2014|pages=456–464|issn=0169-5347|doi=10.1016/j.tree.2014.05.005|pmid=24909948|bibcode=2014TEcoE..29..456F }}</ref> There are results that seem to support this; a 1992 study found a correlation between the song rate of a male and the attractiveness of it (measured on the basis of how much time the female spent with the male).<ref name="Houtman1992"/> However, a 2007 study found that the responsiveness of a female (measured by behaviours indicating an intent to copulate or rejection) was not significantly related to the male's beak colour or its song rate. Song rate was instead hypothesised to draw female's attention to males. According to the author, this meant that the validity of the conclusions of the 1992 experiment needed to be reexamined.<ref name="Forstmeier2007">{{cite journal|last1=Forstmeier|first1=Wolfgang|title=Do individual females differ intrinsically in their propensity to engage in extra-pair copulations?|journal=PLOS ONE|volume=2|issue=9|year=2007|pages=e952|issn=1932-6203|doi=10.1371/journal.pone.0000952|pmid=17895992|pmc=1978515|bibcode=2007PLoSO...2..952F |doi-access=free}}</ref> Combined with the lack of influence that certain morphological traits have, the large control of females over copulation could indicate chase-away sexual selection,<ref name="Forstmeier2004">{{cite journal|last1=Forstmeier|first1=Wolfgang|title=Female resistance to male seduction in zebra finches|journal=Animal Behaviour|volume=68|issue=5|year=2004|pages=1005–1015|issn=0003-3472|doi=10.1016/j.anbehav.2004.02.003|s2cid=53186504}}</ref> where an exaggerated trait is evolved to counter increased resistance by the female to that feature.<ref name="HollandRice1998">{{cite journal|last1=Holland|first1=Brett|last2=Rice|first2=William R.|title=Perspective: Chase-away sexual selection: Antagonistic seduction versus resistance|journal=Evolution|volume=52|issue=1|year=1998|pages=1–7|issn=0014-3820|doi=10.1111/j.1558-5646.1998.tb05132.x|pmid=28568154|doi-access=free}}</ref> An additional theory as to why extra-pair copulation might evolve is the between-sex genetic correlation theory. This theory is based on the lack of definite female benefits in extra-pair copulations, and the benefits that males have by being promiscuous. It states that extra-pair mating behaviour could arise from the same set of loci, and thus that strong selection for extra-pair mating behaviour would indirectly select for promiscuous behaviour in females.<ref name="ForstmeierMartin2011"/>

<!--Paragraph below dedicated to traits that increase EPC, that are meant to guard against EPC, etc.-->
There are several traits correlated with increased extra-pair copulations. Spending time with a mate is important; even more important than the attractiveness of a male (as judged by other females; attractiveness as judged by one female was positively correlated with the judgements of other females).<ref name="Forstmeier2007"/> Symmetry of both plumage, like chest bands, and artificial features, like leg bands, are preferred by the female, as measured by how often the male is displayed to.<ref name="SwaddleCuthill1994">{{cite journal|last1=Swaddle|first1=J. P.|last2=Cuthill|first2=I. C.|title=Female zebra finches prefer males with symmetric chest plumage|journal=Proceedings of the Royal Society B: Biological Sciences|volume=258|issue=1353|year=1994|pages=267–271|issn=0962-8452|doi=10.1098/rspb.1994.0172|s2cid=85258085}}</ref> Because of the prevalence of extra-pair paternity, males have evolved various mechanisms to try and assure their paternity of a clutch. The male guards its mate by following it and stopping extra-pair copulation attempts. Sperm competition, where two or more males attempt to inseminate a single egg, also occurs. This is indicated by the male in a pair copulating with its mate more often the day before egg-starts. This is because the last male to copulate with a female before the next egg has a 70% to 80% chance of fertilising the egg in question.<ref name="BirkheadHunter1989">{{cite journal|last1=Birkhead|first1=T.R.|last2=Hunter|first2=F.M.|last3=Pellatt|first3=J.E.|title=Sperm competition in the zebra finch, ''Taeniopygia guttata''|journal=Animal Behaviour|volume=38|issue=6|year=1989|pages=935–950|issn=0003-3472|doi=10.1016/S0003-3472(89)80135-6|s2cid=53168363}}</ref> Another adaptation to sperm competition is the male ejaculating up to seven times more sperm in extra-pair copulations. The increased amount of sperm occurs because of the combination of ejaculate size being controlled by the time between previous copulations, and the fact that extra-pair copulations occur in the male after its period of within-pair copulation period is complete.<ref name="BirkheadFletcher1995">{{cite journal|last1=Birkhead|first1=T. R.|last2=Fletcher|first2=F.|last3=Pellatt|first3=E. J.|last4=Staples|first4=A.|title=Ejaculate quality and the success of extra-pair copulations in the zebra finch|journal=Nature|volume=377|issue=6548|year=1995|pages=422–423|issn=0028-0836|doi=10.1038/377422a0|bibcode=1995Natur.377..422B |s2cid=4263304}}</ref>

The number of [[bird egg|eggs]] ranges from two to eight eggs per [[clutch (eggs)|clutch]], with five being the most common number.<ref name="Zann335">{{harvnb|Zann|1996|p=335 }}</ref> These eggs are white or pale greyish blue in colour, and have a size of about {{convert|16|by|10|mm|in}}. They are incubated for 14 to 16 days.<ref name="Hauber2014">{{cite book|last=Hauber|first=Mark E.|title=The Book of Eggs: A Life-Size Guide to the Eggs of Six Hundred of the World's Bird Species|url=https://books.google.com/books?id=evQvBAAAQBAJ|date=1 August 2014|publisher=University of Chicago Press|location=Chicago|isbn=978-0-226-05781-1|page=640}}</ref> From about 5%<ref name="GriffithHolleley2010"/> to 11% of offspring are the result of intraspecific [[brood parasitism]], and in cases of parasitism, there is usually only one parasitic egg per nest. Additionally, parasitised nests often have one more egg than non-parasitised nests.<ref name="BirkheadBurke1990"/> The female may follow a mixed strategy with relation to brood parasitism (being parasitic in addition to incubating its own clutch). From about 32% to 58% of females do this, and almost all (about 96%) lay parasitic eggs before incubating their clutch. Unpaired females sometimes lay parasitic eggs, but paired females do not rely solely on parasitism. A female that parasitised a nest in the past is more likely to do so in the future. Most of these eggs are unsuccessful; that is, the host abandons its otherwise empty nest after a parasitic egg is laid. Additionally, successful parasites are more likely to have future success from parasitism.<ref name="SchielzethBolund2010"/> At least during late incubation, the female zebra finch can distinguish its own eggs on the basis of odour. This method of distinction arises from the visual similarity between parasitic and non-parasitic eggs, and the cost associated with raising an egg other than one's own.<ref name="MoskátGolüke2016">{{cite journal|last1=Moskát|first1=Csaba|last2=Golüke|first2=Sarah|last3=Dörrenberg|first3=Sebastian|last4=Krause|first4=E. Tobias|last5=Caspers|first5=Barbara A.|title=Female zebra finches smell their eggs|journal=PLOS ONE|volume=11|issue=5|year=2016|pages=e0155513|issn=1932-6203|doi=10.1371/journal.pone.0155513|pmid=27192061|pmc=4871452|bibcode=2016PLoSO..1155513G |doi-access=free}}</ref> When a bird is parasitised during a nesting attempt, it is less likely to be parasitised again during that season and, at the very least, during the next season (although this could be statistical noise).<ref name="SchielzethBolund2010"/>

Young zebra finches fledge about 17 to 18 days after hatching.<ref name="hbwc"/> They feed themselves by around 35 days after hatching, although they are still socially dependent on their parents during this time; the young become socially dependent between 36 and 50 days after hatching. They also develop sexually dimorphic plumage during this period.<ref name="ZannRunciman2008"/> These finches are quick to attain sexual maturity,<ref name="Zann84–85">{{harvnb|Zann|1996|pp=84–85}}</ref> with most first attempting to form pair bonds and breed when they get close to 80 days in age.<ref name="ZannRunciman2008">{{cite journal|last1=Zann|first1=Richard|last2=Runciman|first2=David|title=Survivorship, dispersal and sex ratios of zebra finches ''Taeniopygia guttata'' in southeast Australia|journal=Ibis|volume=136|issue=2|year=2008|pages=136–143|issn=0019-1019|doi=10.1111/j.1474-919X.1994.tb01077.x}}</ref> During the second half of the breeding season at the Danaher breeding colony, 44% of pairs attempting to breed were formed by individuals that were born earlier in the season.<ref name="Zann84–85"/>

Males and females are very similar in size, but are easily distinguished from one another after reaching maturity, as the males usually have bright orange cheek feathers, red beaks (as opposed to the orange beaks of females), and generally more striking black and white patterns.<ref name="goldenb"/>

====Inbreeding====
[[Inbreeding]] causes early death ([[inbreeding depression]]) in the zebra finch, although it does not seem to affect fertility. Embryos have a much lower survival rate, with a study finding fertile eggs from [[sibling|sibling pairs]] had only about a 25% survival rate, compared to about 41% for unrelated pairs. This early difference in survival eventually becomes null after fledging, with about equal survival rates for offspring from both sibling and unrelated pairs.<ref name="pmid22643890">{{cite journal |vauthors=Hemmings NL, Slate J, Birkhead TR |title=Inbreeding causes early death in a passerine bird |journal=Nature Communications |volume=3 |pages=863 |year=2012 |pmid=22643890 |doi=10.1038/ncomms1870 |bibcode=2012NatCo...3..863H |doi-access=free }}</ref> Inbreeding depression mostly arises due to the expression of deleterious recessive alleles.<ref name="pmid19834483">{{cite journal |vauthors=Charlesworth D, Willis JH |title=The genetics of inbreeding depression |journal=Nature Reviews Genetics |volume=10 |issue=11 |pages=783–96 |year=2009 |pmid=19834483 |doi=10.1038/nrg2664 |s2cid=771357 }}</ref>