Content deleted Content added
No edit summary Tags: Mobile edit Mobile web edit |
Citation bot (talk | contribs) Added doi-broken-date. | Use this bot. Report bugs. | Suggested by Abductive | Category:Nuthatches | #UCB_Category 28/31 |
||
| (25 intermediate revisions by 16 users not shown) | |||
Line 1:
{{short description|Species of bird}}
{{good article}}
{{Speciesbox
| name = Corsican nuthatch
Line 15 ⟶ 16:
| range_map_caption = Distribution of the Corsican nuthatch on the island, according to the [[International Union for Conservation of Nature]].<ref name="iucn status 13 November 2021"/>
}}
The '''Corsican nuthatch''' ('''''Sitta whiteheadi''''') is a [[species]] of bird in the nuthatch [[Family (biology)|family]] [[Sittidae]]. It is a relatively small nuthatch, measuring about {{convert|12|cm|in|abbr=on}} in overall length. The {{birdgloss|upperparts}} are bluish gray, the {{birdgloss|underparts}} grayish white. The male is distinguished from the female by its entirely black {{birdgloss|crown}}. The species is [[Non-migratory|sedentary]], territorial and not very shy. It often feeds high in [[Pinus nigra|Corsican pines]], consuming mainly [[pine nut]]s, but also catching some flying [[insects]]. The breeding season takes place between April and May; the nest is placed in the trunk of an old pine, and the [[Clutch (eggs)|clutch]] has five to six eggs. The young [[fledge]] 22 to 24 days after hatching.
The Corsican nuthatch is found only on the island of [[Corsica]], where it populates the old forests of high altitude [[Pinus nigra|laricio pines]], descending lower in winter. Its [[scientific name]] comes from [[John Whitehead (explorer)|John Whitehead]], the ornithologist who brought the bird to the attention of the scientific community in 1883. The Corsican nuthatch is closely related to the [[Chinese nuthatch]] (''S. villosa'') and the [[red-breasted nuthatch]] (''S. canadensis''). It is threatened by loss of nesting sites and [[habitat fragmentation]], with an estimated population size of about 2,000 individuals, possibly in moderate decline. Due to the small population size and the limited range, the conservation status of the Corsican nuthatch is classed as "[[Vulnerable species|vulnerable]]" by the [[International Union for Conservation of Nature]].
== Taxonomy ==
===Discovery and
[[File:SittaWhiteheadiKeulemans2.jpg|right|thumb|alt=Illustration of the pair of birds.|The first plate depicting the species, in this case a pair (male above and female below), and accompanying the June 1884 publication by [[Richard Bowdler Sharpe]].]]
The Corsican nuthatch was discovered when ornithologist [[John Whitehead (explorer)|John Whitehead]] went to observe [[alpine swift]] (''Tachymarptis melba'') on June 13, 1883. Whitehead, who had spent much of the previous years in Corsica, spotted and shot a male Corsican nuthatch. He kept the specimen's skin and did not bother with it until October, when he asked [[Richard Bowdler Sharpe]] for help in naming some small birds he had collected; although the bird's head was damaged by the collection method, Sharpe assured him that the species was not yet [[Species description|described]].<ref name="Whitehead"/> Whitehead thought the bird was extremely localized and did not give the precise locality where he collected the first specimens for fear that the species would be exterminated by additional collections.<ref name="Jourdain"/>
Line 26 ⟶ 27:
Whitehead returned to Corsica in May 1884 and found a male, which he recognized by its black {{birdgloss|crown}}. After killing it, he waited to see the accompanying female, killed it as well, and then collected three more specimens from a small flock. In the following days, he observed a pair coming and going with nesting material in a hole six meters above the ground in the trunk of a very old pine. He located other nests, some {{convert|30|m|in|abbr=on}} above the ground, and opened two of them, finding 5 eggs in each, which he collected.<ref name="Whitehead"/>
The Italian ornithologist [[Enrico Hillyer Giglioli]] reported in 1890 that he had observed the bird on September 16, 1877, at [[Ponte Leccia]], almost six years before Whitehead, but mistaking it for a [[Eurasian nuthatch]] (''S. europaea''), he did not bother to shoot it.<ref>{{cite
The first works concerning the biology of the bird were only carried out in the 1960s by the German ornithologist [[Hans Löhrl]], who studied the reproduction, feeding and behavior of the species. In 1976, Claude Chappuis described the voice of the species in an article dedicated to the vocalizations of birds from Corsica and the [[Balearic Islands]].<ref name="Habitat management"/> In the 1980s, the Italian ornithologists Pierandrea Brichetti and Carlo Di Capi studied the reproduction of the Corsican nuthatch. Since the 1990s, the species has been studied closely by local groups, and in particular by ornithologists Jean-Claude Thibault, Pascal Villard and Jean-François Seguin.<ref name="sittelle">{{cite book|last1=Thibault |first1=Jean-Claude|last2=Seguin |first2=Jean-François|last3=Norris |first3=Ken |url=https://archive.wikiwix.com/cache/index2.php?url=http%3A%2F%2Fwww.developpement-durable.gouv.fr%2FIMG%2Fpdf%2FPNA_Sittelle_corse.pdf%2Findex.html#federation=archive.wikiwix.com|place=[[Regional Natural Park of Corsica]]|title= Restoration plan for the Corsican nuthatch|year=2000}}</ref>{{Rp|4}}
In the summer of 2006, Dutchmen participating in an entomological expedition incidentally observed a pair of nuthatches in the [[Altai Mountains|Altai]], near the meeting point of [[China]], [[Kazakhstan]], [[Mongolia]] and [[Russia]], in a pure [[larch]] forest (''Larix sp.''). The male has a black crown, and the female does not, and both have a dark {{birdgloss|eyestripe}} topped by a white [[supercilium]]. The closest species geographically that might fit this description is the [[Chinese nuthatch]] (''S. villosa''), which would then be far from its known distribution, and which has more buffy underparts than the observed individuals. This record could be indicative of a much wider distribution of the Chinese species, or the bird could be an as yet undescribed species related to ''S. whiteheadi'' and ''S. villosa''.<ref>{{cite journal | last1=T. Smit| first1=John |last2= Zeegers | first2= Theo |last3= van den Heuvel| first3= Esther |last4= Roels | first4= Bas |year=2007 |url=https://www.dutchbirding.nl/journal.php?show_summary=true&journalid=210&contentid=6|title=Unidentified nuthatch in Siberian Altay in July 2006|journal= Dutch Birding|volume=29|issue=3| pages= 636}}</ref>
===Nomenclature
The Corsican nuthatch was described by Sharpe in March 1884, based on the first male specimen collected by Whitehead, who was thus given the [[Specific name (zoology)|specific name]]. Whitehead sent a second male to Sharpe, who presented it in May to the ''[[Zoological Society of London]]''.<ref>{{cite journal |date=May 1884|url=https://archive.org/details/proceedingsofgen84busi/page/328/mode/2up?view=theater|title=Summary of the session of May 20, 1884 |journal= Proceedings of the Zoological Society of London|volume=52|issue=2| pages= 329 }}</ref> In June, Sharpe completed the description of the species after Whitehead sent him a female.<ref name="Brichetti and Di Capi"/> The Corsican nuthatch is sometimes placed in a [[subgenus]], ''Micrositta'', described by the Russian ornithologist [[Sergei Buturlin]] in 1916,<ref name="Matthysen">{{cite book | last=Matthysen | first=Erik |year=1998|url=https://www.dutchbirding.nl/journal.php?show_summary=true&journalid=210&contentid=6|title=The Nuthatches|publisher=Appendix I – Scientific and Common Names of Nuthatches| page= 270|isbn=978-0-85661-101-8}}</ref> and has no [[subspecies]].<ref>{{cite web| title=Nuthatches, Wallcreeper, treecreepers, mockingbirds, starlings, oxpeckers – IOC World Bird List | website=IOC World Bird List – Version 11.2 | url=http://worldbirdnames.org/bow/nuthatch | access-date=26 Dec 2021}}</ref>
The Corsican nuthatch was subsequently considered a subspecies of the [[red-breasted nuthatch]] (''S. canadensis'') from 1911 until the 1950s.<ref name="Jourdain"/><ref name="sittelle" />{{Rp|6–8}} In 1957, American ornithologist [[Charles Vaurie]] explained that the morphology did not allow one to be sure that the Corsican nuthatch was a distinct species, and that it was probably better to consider it as belonging to the "''canadensis''" group, regrouping the species ''S. canadensis'', ''S. whiteheadi'' and ''S. villosa'';<ref>{{cite journal | last=Vaurie| first=Charles|date=1957|url=https://archive.wikiwix.com/cache/display2.php/N1854.pdf?url=http%3A%2F%2Fdigitallibrary.amnh.org%2Fdspace%2Fbitstream%2Fhandle%2F2246%2F3596%2F%2Fv2%2Fdspace%2Fingest%2FpdfSource%2Fnov%2FN1854.pdf%3Fsequence%3D1|title=Systematic Notes on Palearctic Birds. No. 29. The Subfamilies Tichodromadinae and Sittinae|journal=American Museum Novitates| pages= 1–26 }}</ref> The German ornithologist [[Hans Löhrl]], after studying the ecology and behavior of the birds of Latin America and Corsica, and through the publication of his field notes between 1960 and 1961, disagreed with Vaurie's position.<ref>{{cite journal | last=Löhrl| first= Hans|year=1960|title=Vergleichende Studien über Brutbiologie und Verhalten der Kleiber ''Sitta whiteheadi'' Sharpe und ''Sitta canadensis'' L.|journal= Journal
===Molecular phylogeny and
In 1998, Eric Pasquet studied the [[cytochrome b]] of the [[mitochondrial DNA]] of a dozen nuthatch species, including the various species of the ''Sitta canadensis'' group,<ref name="Phylogeny">{{cite journal | title=Phylogeny of the nuthatches of the ''Sitta canadensis'' group and its evolutionary and biogeographic implications | first=Eric | last=Pasquet| name-list-style=amp | journal=The Ibis | volume=140| issue=1| pages=150–156|date=1998 | doi=10.1111/j.1474-919X.1998.tb04553.x}}</ref> which he defined as comprising six species, which are also those of what is sometimes treated as the subgenus [[Sitta]] (''Micrositta''):<ref name="Matthysen"/> ''canadensis'', ''villosa'', ''yunnanensis'', ''whiteheadi'', ''krueperi'' and ''ledanti''. Pasquet concludes that the Corsican nuthatch is [[Phylogeny|phylogenetically]] related to the Chinese nuthatch and the red-breasted nuthatch, these three species forming the [[sister group]] of a [[clade]] including Krüper's nuthatch and the Algerian nuthatch. The first three species would even be close enough to constitute subspecies, rejecting Vielliard's "mesogean" theory and thus confirming Vaurie's conclusions.<ref name="Phylogeny"/><ref name="Matthysen"/>{{Rp|190}} For the sake of [[Taxonomy (biology)|taxonomic]] stability, however, all retain their full species status.<ref name="sittelle" />{{Rp|6–8}} In 2014, Eric Pasquet and colleagues published a phylogeny based on [[Nuclear DNA|nuclear]] and mitochondrial DNA of 21 nuthatch species and confirmed the relationships of the 1998 study within the "''canadensis'' group", adding the [[Yunnan nuthatch]], which was found to be the most [[Basal (phylogenetics)|basal]] of the species.<ref name="Packert2014">{{cite journal | title=Evolution within the nuthatches (Sittidae: Aves, Passeriformes): molecular phylogeny, biogeography, and ecological perspectives | first1=Eric | last1=Pasquet | first2=F Keith | last2=Barker | first3=Jochen | last3=Martens | first4=Annie | last4=Tillier | first5=Corinne | last5=Cruaud | first6=Alice | last6=Cibois | name-list-style=amp | journal=Journal of Ornithology | volume=155 | issue=3 | pages=755 |date=2014 | doi=10.1007/s10336-014-1063-7| doi-broken-date=2024-05-03 | s2cid=17637707 }}</ref> The study findings align with the morphology of the species, the red-breasted nuthatch, Corsican nuthatch and Chinese nuthatch sharing as a derived character the entirely black crown only present in males, a unique trait in the Sittidae and related families. The second clade, which includes Krüper's and Algerian nuthatches, would have a black front crown in males, this sexual dimorphism being absent in young individuals.<ref name="Phylogeny"/>
The phylogeny established, Pasquet concludes that the paleogeographic history of the group would be as follows: the divergence between the two main clades of the "''canadensis'' group" appears more than five million years ago, at the end of the [[Miocene]], when the clade of ''krueperi'' and ''ledanti'' settles in the [[Mediterranean basin]] at the time of the [[Messinian salinity crisis]]; the two species constituting it diverge 1.75 million years ago. The other clade split into three with populations leaving [[Asia]] from the east, giving rise to the red-breasted nuthatch, and then from the west, about one million years ago, marking the separation between the Corsican and Chinese nuthatches.<ref name="Phylogeny"/> Current distributions do not necessarily accurately reflect ancestral ones, however, and the Corsican nuthatch may be a [[paleoendemic]] that once had a much wider distribution and underwent reductions in pine distribution; "trapped" in Corsica, it would have evolved by [[vicariance]].<ref name="sittelle" />{{Rp|6–8}}<ref name="Phylogeny"/>
The simplified [[cladogram]] below is based on the [[phylogenetic analysis]] of Packert and colleagues (2014):<ref name="Packert2014"/>
{|
Line 68 ⟶ 69:
== Description ==
[[File:Pica-soques cors (Sitta whiteheadi) (cropped).jpg|right|thumb|alt=A gray bird with black crown at the branch of tree|A female in the gorges of [[Restonica]] near [[Corte, Haute-Corse|Corte]], has a dark gray crown towards the front blending rapidly into the gray-blue of the back.]]
===Plumage and measurements===
The Corsican nuthatch is a small bird, measuring {{convert|11|-|12|cm|in|abbr=on}} long<ref name="Lars Svensson">{{Cite journal |last=Svensson |first=Lars |title=The ornitho guide: The most complete guide to the birds of Europe, from North Africa and the Middle East: 900 species|journal= The Naturalist's Guides|date=August 2010|pages=348–349|isbn=978-2-603-01695-4}}</ref> with a wingspan of {{convert|21|-|22|cm|in|abbr=on}}<ref name="Avibirds">{{cite book |url=https://archive.wikiwix.com/cache/index2.php?url=http%3A%2F%2Fwww.avibirds.com%2Feuhtml%2FCorsican_Nuthatch.html#federation=archive.wikiwix.com|title= Corsican Nuthatch
The {{birdgloss|upperparts}} are overall bluish gray, the belly pale grayish buff with the throat whiter. The male has a black crown and forehead, and a black eyestripe, separated from the crown by a broad, sharp white supercilium.<ref name="Oiseaux">{{cite book |url=https://www.oiseaux.net/oiseaux/sittelle.corse.html|title= ''Sitta whiteheadi''
===Vocalizations===
Line 78 ⟶ 80:
===Similar species===
The Corsican nuthatch is the only nuthatch found in [[Corsica]], however, it may be reminiscent of the [[coal tit]] ''(Parus ater)'', which is
== Distribution and habitat ==
The Corsican nuthatch is the only
The Corsican nuthatch favors [[Pinus nigra|Corsican pines]] ''(Pinus nigra laricio)'' forests interspersed with clearings; this habitat is fairly dry in the summer (three weeks to two months of drought) and experiences heavy rainfall in the off-season ({{convert|800|-|1,800|mm|in|abbr=on}} per year).<ref name="sittelle" />{{Rp|9–14}} This nuthatch is [[Non-migratory|sedentary]]; it generally lives in deep valleys between {{convert|1,000|m|in|abbr=on}} and {{convert|1,500|m|in|abbr=on}} above sea level between April and October, but can be found from {{convert|750|-|1,800|mm|in|abbr=on}} above sea level, although the more open forests at higher elevations are less suitable. It descends lower in winter, and may then inhabit mixed forests of Corsican and [[Pinus pinaster|maritime pines]] ''(Pinus pinaster)''<ref name="Lars Svensson"/><ref name="Oiseaux"/> or forests of [[Abies alba|white fir]] ''(Abies alba)''; however, its stand indices are significantly lower than in pure Corsican pines forests.<ref name="sittelle" />{{Rp|15–25}} It avoids hardwood-dominated or mixed woodlands.<ref name="sittelle" />{{Rp|9–14}}
Old pines provide the nuthatch with abundant food, and the species is absent from sectors where trees are less than {{convert|28|cm|in|abbr=on}} in diameter, and where the Corsican pine is in the minority compared to other species. The places most likely to shelter the Corsican nuthatch have large trees (over {{convert|16|m|in|abbr=on}} high) and large diameter (over {{convert|58|cm|in|abbr=on}}). The preference of the bird for the Corsican pine over the maritime pine could be explained by the toughness of the seeds of the latter.<ref name="Birds Habitat"/> From a historical perspective, Thibault and colleagues explain in 2002 that "the Corsican nuthatch and the Corsican pine, probably present on the island since at least the middle of the [[Quaternary]], had to face the last climatic fluctuations of the [[Pleistocene]], which caused deep modifications in the composition and distribution of the vegetation. It is likely that the nuthatch survived in the Corsican pines throughout this period.<ref>{{cite journal | last1= Thibault| first1= Jean-Claude|last2=Seguin|first2=Jean-Francois|last3=Villard |first3=Pascal|last4=Prodon|first4=Roger|title= Le pin Laricio (Pinus nigra laricio) est-il une espèce clé pour la Sittelle Corse (''Sitta whiteheadi'')|journal=Revue d'écologie|volume=57|issue=3–4|date=2002|
== Behaviour and ecology==
Like all nuthatches, the Corsican nuthatch can move head down along branches, and is rarely found on the ground. It is a territorial bird and are not shy. It lives in [[monogamous]] couples evolving all year long on the same territory of three to ten [[hectare]]s, the two birds of the couple defending it from intruders, of the same species or of another. The home range, the area where the birds generally live within their territory, varies in size, depending on the season and age of the birds, but especially on the cone production of the pines.<ref name="sittelle" />{{Rp|15–25}}<ref name="Birds Habitat"/>
===Food and feeding===
[[File:Sitta whiteheadi - Christoph Moning - 6 (cropped).jpeg|right|thumb|alt=A gray bird in upside down|The Corsican nuthatch is an agile bird that likes to prospect upside down.]]
The Corsican nuthatch consumes mainly pine nuts, but also small flying insects in summer. From March to November, small [[arthropods]] (adult insects and their larvae, spiders) represent the main part of its diet; it catches them in [[Bird flight|flight]] but more generally in the trees;<ref name="Birds Habitat"/> it makes a quarter of its captures in flight, from a lookout post, and exploits the rest of the time the substrates provided by the trees.<ref>{{cite journal | last1= Villard | first1=Pascal | last2= Bichelberger | first2=S. | last3= Seguin | first3=Jean-François| last4=Thibault |first4=Jean-Claude|year=2003| title= The quest for food of the Corsican nuthatch (''Sitta whiteheadi'') in the Corsican pines (''Pinus nigra laricio'')| journal=Vie et Milieu| volume=53| issue=1| pages=27–32}}</ref> In spring and summer, it is more likely to be found in the treetops, [[forage|foraging]] high up in the foliage of pine trees, at the end of branches, like a [[chickadee]];<ref name="Lars Svensson"/> in autumn, however, it searches for food along the trunks and on large branches, and may also form [[Mixed-species foraging flock|mixed feeding flocks]] with other small [[passerine]]s outside the breeding season.<ref name="Oiseaux"/> November marks the beginning of the opening of pine cones, from which the Corsican nuthatch extracts seeds with its fine bill.<ref name="Birds Habitat"/> In years of high production, the nuthatch may find food resources in the cones until March. As nuthatches often do, the Corsican nuthatch hides some seeds under the bark or under [[lichens]] or plant debris, and consumes them in the off-season, especially when early spring snows prevent access to pine cones, or when cones remain closed on wet, cold days.<ref name="Oiseaux"/><ref>{{cite
===Breeding===
[[File:Sitta whiteheadi nest.jpg|right|thumb|alt=Illustration of the nest|Illustration by [[John Whitehead (explorer)|John Whitehead]] of the first nest he opened in 1884.]]
[[File:Sitta whiteheadi MHNT.ZOO.2010.11.183.11.jpg|thumb|''Sitta whiteheadi'' - [[MHNT]]]]
Male Corsican nuthatches begin singing in late December, but the breeding season occurs in April–May. In years of high cone production, breeding occurs early; in years of low production, nuthatches must wait until insects are present in large quantities.<ref name="Bird study">{{cite journal | last1=Thibault| first1=Jean-Claude| last2= Villard | first2=Pascal |year=2005|journal=Bird Study| title=Reproductive ecology of the Corsican Nuthatch ''Sitta whiteheadi'': capsule food availability determines date of clutch initiation, and predation is the main cause of clutch failure| volume=52| issue=3| pages= 282–288| doi=10.1080/00063650509461401| s2cid=88027746|
A 2005 study reported that the nests of different pairs were located {{convert|284|-|404|m|ft|abbr=on}} apart depending on the year (between 1998 and 2003).<ref name="Bird study"/> Both members of the pair excavate the nest, often reusing cavities excavated by [[great spotted woodpecker]]s (''Dendrocopos major''), but avoiding the high risk of predation from the former nests of these birds. There can be two entrances to the cavity if the trunk is particularly rotten. The entrance is {{convert|3|-|4|m|in|abbr=on}} wide, and the cavity averages {{convert|56 |×|109 |mm|in|abbr=on|sigfig=2}} with an average depth of {{convert|12|cm|in|abbr=on}}.<ref name="Data nests">{{cite journal | last1=Villard | first1=Pascal | last2= Thibault | first2= Jean-Claude |year=2001|journal=Alauda | title= Data on nests, chick growth and parental care in the Corsican nuthatch (''Sitta whiteheadi'') | volume= 69| pages= 465–474}}</ref> The nest is placed between {{convert|2|-|30|m|in|abbr=on}} above the ground. It is made of various plant materials (pine thorns, bark, and shavings) and lined with softer materials such as feathers, moss, horsehair, or lichen.<ref name="Oiseaux"/>
Line 102 ⟶ 105:
The female lays in late April or early May, four to six (average 5.1)<ref name="Bird study"/> oval white eggs with reddish-brown spots, especially on the broad end, with "a few faint brown or dark gray-purple markings.<ref name="Oiseaux"/> Whitehead compares the eggs in size to those of the [[great tit]] (''Parus major'');<ref name="Whitehead">{{cite journal | last= Whitehead| first=John|date=1885|journal=The Ibis|url= https://archive.org/details/ibis35brit/page/28/mode/2up?view=theater|title= Ornithological notes from Corsica | volume= 27|issue=1| pages=24–48|doi=10.1111/j.1474-919X.1885.tb06232.x}}</ref> according to Jourdain, who compares 42 eggs (14 collected by Whitehead, the other 28 by himself), they measure on average {{convert|17.18 |×|12.96|mm|in|abbr=on|sigfig=2}}. The average weight, calculated for 17 of these eggs, is 82.2 milligrams.<ref name="Jourdain">{{cite journal | last= Jourdain | first= Francis Charles Robert |date=1911|journal=The Ibis|url=https://archive.org/details/ibis951911brit/page/440/mode/2up?view=theater|title= Notes on the Ornithology of Corsica – part II|series=9th series| volume=5|issue=1| pages=440–445}}</ref> Brooding lasts from 14 to 17 days; it is carried out by the female alone, which the male feeds on average 3.2 times per hour. The beak and wing of the chicks grow steadily, while the tarsus stabilizes by the twelfth day; the crown darkens by the eleventh day, and the young are fully plumaged after an average of twenty days.<ref name="Data nests"/>
The brood usually has 3 to 6 (average 4.3) fledglings, which leave the nest at 22 to 24 days of age.<ref name="Avibirds"/><ref name="Bird study"/> If the first brood fails or is lost, the pair makes a second brood between May 28 and June 16; one-third of these replacement broods are made in another tree. From one year to the next, nearly half of the pairs change trees to nest in.<ref name="Bird study"/> The young may breed at one year of age. The annual survival rate has been estimated at 61.6% for males (more than three out of five individuals make it through the year);<ref>{{cite journal
== Threats and Conservation ==
===Numbers and status===
An estimate from the 1960s–1980s counted 2,000 to 3,000 pairs, spread over {{Convert|240|km|mi|abbr=on}}, whereas in the 1950s there were nearly 3,000 pairs over {{Convert|430|km|mi|abbr=on}}.<ref name="Birds Habitat"/><ref name="Oiseaux"/> In 2000, Thibault and colleagues estimated the numbers at 2,075–3,010 pairs.<ref name="sittelle" />{{Rp|9–14}} In 2013, according to the [[International Union for Conservation of Nature]], Thibault and colleagues estimate the Corsican nuthatch population at 3,100–4,400 mature individuals, or 4,600–6,600 birds in total.<ref name="iucn status 13 November 2021"/> A 2011 estimate of the range put it at {{Convert|185|km|mi|abbr=on}}.<ref name="Distribution and population">{{cite journal | title=Distribution and population size of the Corsican Nuthatch ''Sitta whiteheadi'' | first1=Jean-Claude | last1=Thibault|first2=Didier | last2=Hacquemand |first3=Pasquale | last3=Moneglia |first4=Hervé | last4=Pellegrini | first5=Roger | last5=Prodon |first6=Bernard | last6=Recorbet |first7= Jean-François| last7=Seguin |first8=Pascal | last8=Villard |name-list-style=amp | journal=Bird Conservation International| volume=21| issue=2| pages=199–206|date=2011 | doi=10.1017/S0959270910000468 | s2cid=85727767 | doi-access=free }}</ref> The Corsican nuthatch was considered by the International Union for Conservation of Nature as "[[Near-threatened species|near threatened]]" in 1988, and "[[least concern]]" in 2004, 2008 and 2009. Since 2010, it has been considered "[[Vulnerable species|vulnerable]]",<ref name="iucn status 13 November 2021"/> with Thibault and colleagues estimating a 10% decline over the previous ten years in a 2011 paper.<ref name="Distribution and population"/>
===Threats===
[[File:Gargla.jpg|right|thumb|alt=The gray winged-bird at the trunk of tree|The [[Eurasian jay]] counts among the predators of the young Corsican nuthatches.]]
The decrease in numbers can be explained by fire and logging: the Corsican pines to which the species is attached regenerate less quickly than they otherwise disappear, and the felling of dead pines poses problems for the nesting of this nuthatch.<ref name="iucn status 13 November 2021"/><ref name="Oiseaux"/> In addition to destroying the birds' territories, regrowth after the fire has passed results in the replacement of the laricio pine by maritime pine or [[Quercus ilex|holm oak]] (''Quercus ilex'').<ref name="Birds Habitat"/> A study carried out on the consequences of the fires of the summer of 2000, which affected several large Corsican massifs, concluded that the direct consequences (disappearance of territories) and indirect consequences (difficulties in nesting and feeding in winter) could have affected 4% of the species' population.<ref>{{cite journal | title=Estimation of the impact of fires in the summer of 2000 on the population of a threatened endemic bird: the Corsican nuthatch (''Sitta whiteheadi'') | first1=Jean-Claude | last1=Thibault |first2=Roger | last2=Prodon |first3=Pasquale | last3=Moneglia | journal=Ecologia Mediterranea | volume=30| issue=2| pages=195–203 |date=2004| doi=10.3406/ecmed.2004.1459 }}</ref> For the same period in the [[Restonica]] gorges, 6 out of 12 territories were lost.<ref>{{cite journal | title=The consequences of the summer 2000 fire on the population of the Corsican Nuthatch (''Sitta whiteheadi'') in the Restonica Valley, Corsica| first1=Jean-Claude | last1=Thibault |first2=Nicolas | last2=Beck |first3=Pasquale | last3=Moneglia | journal=Alauda | volume=70| issue=4| pages=431–436|date=2002}}</ref> The major impacts of the forest fires of August 2003 also led to a decline in the population, which was reduced by 37.5% the following spring.<ref>{{cite journal | title=Habitat selection of the Corsican Nuthatch (''Sitta whiteheadi'') after a fire|url=https://www.researchgate.net/publication/226657002| first1=Pasquale | last1=Moneglia |first2=Aurélien | last2=Besnard |first3=Jean-Claude | last3=Thibault |first4=Roger|last4=Prodon | journal=Journal of Ornithology| volume=150| issue=3| pages=577–583|date=2009|doi= 10.1007/s10336-009-0379-1|doi-broken-date=2024-05-03 |s2cid=46106724|via=[[ResearchGate]]}}</ref>
Predators of the Corsican nuthatch include the great spotted woodpecker, which may attack nests and young birds by enlarging the nest cavity to gain access to nuthatch offspring; not all individuals necessarily attack nests, and nuthatches and woodpeckers may even nest in the same tree. The
The study of the habitat structure of the Corsican nuthatch has shown that the fragmentation of its habitat, which leads to a local concentration of populations, could be a new threat. Nuthatches avoid open areas and young plantations that present an increased risk of predation, only crossing them if these areas are sufficiently narrow.<ref name="sittelle" />{{Rp|34–42}} A 2011 study attempted to quantify the impact of global warming on the future distribution of Corsican and maritime pines; taking only climate disruption into account, it is likely that by 2100, 98% of the Corsican nuthatch's range will still be likely to support it, and that this distribution will even expand by 10%. The bird's habitat is thus more threatened by the increase in frequency and importance of fires and the increase in human activities than by [[climate change]].<ref>{{cite journal | title=Back from a predicted climatic extinction of an island endemic: a future for the Corsican nuthatch | first1=Morgane | last1=Barbet-Massin |first2=Frédéric | last2= Jiguet | journal= PLOS ONE| volume=6| issue=3| pages=577–583|date=2011|doi= 10.1371/journal.pone.0018228|pmid = 21464916|pmc = 3064676|bibcode = 2011PLoSO...618228B|doi-access = free}}</ref>
Line 123 ⟶ 126:
===In culture===
The Corsican nuthatch is sometimes referred to as Whitehead's nuthatch,<ref>{{cite journal | title=Order of October 29, 2009 setting the list of protected birds on all of the territory and the methods of their protection|last=Paris|first= Paul | journal= Fauna of France
== References ==
| |||