Examine individual changes

'{{Short description|Species of bird}} {{good article}} {{speciesbox | image=Zavattariornis stresemanni -Yabello Wildlife Sanctuary, Ethiopia-8.jpg | image_caption=At [[Yabello Wildlife Sanctuary]], Ethiopia | status = EN | status_system = IUCN3.1 | status_ref = <ref name=IUCN2012>{{cite iucn |author=BirdLife International. |year=2016 |title=''Zavattariornis stresemanni'' |volume=2016 |page=e.T22705877A94039369 |doi=10.2305/IUCN.UK.2016-3.RLTS.T22705877A94039369.en |access-date=3 May 2021}}</ref> | genus = Zavattariornis | parent_authority = Moltoni, 1938 | species = stresemanni | authority = [[Edgardo Moltoni|Moltoni]], 1938 | range_map = Zavattariornis stresemanni distribution map.png | range_map_caption = Distribution map }} '''Stresemann's bushcrow''' ('''''Zavattariornis stresemanni'''''), also known as the '''Abyssinian pie''', '''bush crow''', '''Ethiopian bushcrow''', or by its generic name '''''Zavattariornis''''', is a rather [[starling]]-like bird, which is a member of the crow family, [[Corvidae]]. It is slightly larger than the [[North America]]n [[blue jay]] and is a bluish-grey in overall colour which becomes almost white on the forehead. The throat and chest are creamy-white with the tail and wings a glossy black. The black [[feather]]s have a tendency to bleach to brown at their tips. The iris of the bird is brown and the eye is surrounded by a band of naked bright blue skin. The [[beak|bill]], legs, and feet are black. Feeding is usually in small groups and the bird takes mainly [[insect]]s. Breeding usually starts in March, with the birds building their nest high in an [[acacia]] tree. The birds usually lay five to six cream [[bird egg|eggs]] with lilac blotches. The [[bird nest|nest]] itself is globular in shape with a tubular entrance on top. It is possible that more than just the breeding pair visit the nest and that the young of previous years help in rearing the young. The range of this species is quite restricted, it being confined to thorn [[acacia]] country in southern [[Ethiopia]] near Yavello (Javello), Mega, and Arero. It can be curiously absent from apparently suitable country near these areas; the reasons for this were formerly unclear, but are now thought to be related to the species requiring a "bubble" of lower temperature for proper foraging, which is only present within its small range, making it one of the few warm-blooded animals whose survival is wholly dependent on temperature (along with the [[Sympatry|sympatric]] [[white-tailed swallow]]). This requirement makes it extremely [[Climate change vulnerability|vulnerable to climate change]], and massive declines and even potential [[Extinct in the wild|extinction in the wild]] are projected in the future, making it one of the birds most threatened by climate change.<ref name=":0" /> ==Taxonomy== Stresemann's bushcrow was formally described in 1938 by the Italian ornithologist [[Edgardo Moltoni]].<ref>{{ cite journal | last=Moltoni | first=Edgardo | author-link=Edgardo Moltoni | date=1938 | title=''Zavattariornis stresemanni'' novum genus et nova species Corvidarum | language=Italian | journal=Ornithologische Monatsberichte | volume=46 | pages=80–83 | url=https://www.zobodat.at/pdf/Ornithologische-Monatberichte_46_0080-0083.pdf }}</ref> The species has been placed in several bird [[family (biology)|families]] since its description.<ref name="HBW608"/> It has long been considered a member of the crow family [[Corvidae]]; however, several atypical features, such as its lice being from the suborder [[Mallophaga]], its bare facial skin being capable of movement, and the structure of its [[palate]], have suggested that it may belong in another family.<ref name="HBW608"/> Some authors placed the species within the starling family [[Sturnidae]] due to the bushcrow's similarities in behavior and size with the [[wattled starling]].<ref name="HBW608"/> Other authors have placed it in its own monotypic family, Zavattariornithidae.<ref name="HBW608"/> DNA-sequencing analysis supports its placement in the corvids, with its closest relatives being the [[ground jay]]s, and the [[piapiac]].<ref>{{Cite journal | last1=McCullough | first1=J.M. | last2=Hruska | first2=J.P. | last3=Oliveros | first3=C.H. | last4=Moyle | first4=R.G. | last5=Andersen | first5=M.J. | date=2023 | title=Ultraconserved elements support the elevation of a new avian family, Eurocephalidae, the white-crowned shrikes | journal=Ornithology | pages=ukad025 | doi=10.1093/ornithology/ukad025 | doi-access=free }}</ref> It has been suggested that the bushcrow is a surviving [[Relict (biology)|relict]] ancestor to several of these relatives.<ref name="Madge123">{{Harvnb|Madge|Burn|1994|p=123}}</ref> This species has numerous common names, including Stresemann's bushcrow, bush-crow, Ethiopian bushcrow, Abyssinian bushcrow, and Zavattariornis.<ref name="HBW608">{{Harvnb|dos Anjos|Debus|Madge|Marzluff|2009|p=608}}</ref> The genus name ''Zavattariornis'' commemorates [[Edoardo Zavattari]], an Italian zoologist and explorer who served as the director of Rome University's Zoological Institute between 1935 and 1958.<ref>{{cite book |last=Jobling |first=James A. |year=2010 |title=The Helm Dictionary of Scientific Bird Names |url=https://archive.org/details/Helm_Dictionary_of_Scientific_Bird_Names_by_James_A._Jobling |publisher=Christopher Helm |location=London |isbn=978-1-4081-2501-4 |page=[https://archive.org/details/Helm_Dictionary_of_Scientific_Bird_Names_by_James_A._Jobling/page/n413 413]}}</ref> Its name commemorates [[Erwin Stresemann]], a German [[ornithologist]].<ref>{{Cite web|url=https://blogs.scientificamerican.com/expeditions/bush-crow-diaries-the-mystery-of-the-abyssinian-pie/|title=Bush-crow diaries: The mystery of the Abyssinian Pie|first=Samuel|last=Jones|website=Scientific American Blog Network}}</ref> ==Description== The Stresemann's bushcrow is about {{convert|28|cm|in|sp=us}} long and weighs {{convert|130|g|oz|sp=us}}.<ref name="HBW608"/> The genders look similar and are not [[sexually dimorphic]].<ref name="HBW609"/> Overall it is pale grey with a black tail and wings.<ref name="HBW608"/> The head, mantle, scapulars, back, rump, and uppertail coverts are all a pale grey.<ref name="HBW608"/> The feathers on the forehead, upper ear-coverts, and throat fade into white.<ref name="HBW608"/> The bright azure skin around the bushcrow's eye is featherless and can be inflated, narrowing the blackish-brown eye into a slit.<ref name="HBW608"/><ref name="HBW609">{{Harvnb|dos Anjos|Debus|Madge|Marzluff||2009|p=609}}</ref> The feathers behind the eye are capable of moving to reveal an oblong pink patch of skin.<ref name="HBW608"/> The bird's black [[beak]] decurves into a sharply pointed tip and is relatively small for a corvid.<ref name="HBW608"/><ref name="HBW609"/> This beak is {{convert|33|to|39|mm|in|sp=us}} long.<ref name="Madge123"/> The feathers on the bird's chin are fine and can form a small tuft when erected.<ref name="HBW608"/> The bushcrow's breast and flanks are pale grey, fading into white on the rear flanks, belly, and undertail.<ref name="HBW609"/> On the wings, the lesser and median upper-wing coverts are grey, while the rest of the wing is a slightly glossy blue-black.<ref name="HBW608"/><ref name="HBW609"/> Its blue-black tail is relatively long and square-ended.<ref name="HBW608"/> Its legs are black.<ref name="HBW609"/> When the plumage becomes worn, the upperparts appear to have a brownish tinge.<ref name="Madge123"/> The juvenile Stresemann's bushcrow is slightly duller than the adult, and the feathers of the body and upperwings are fringed with creamy-fawn.<ref name="HBW609"/> The facial skin, bill, and legs are also a dull grey.<ref name="Madge123"/> The bushcrow is a very vocal species, particularly when foraging.<ref name="HBW609"/> Its main contact call has been described as a single metallic "kej".<ref name="HBW609"/> While flying, the species frequently calls out a nasal, rapid "kerr kerr kerr".<ref name="HBW609"/> While these are the most frequent vocalizations, several others are known.<ref name="HBW609"/> Allopreening adults utter a metallic "kaw, kaw, kaw".<ref name="HBW609"/> Foraging birds call out "how, how, how", a single, quiet "quak", and a soft, repeated "guw".<ref name="HBW609"/> While building its nest, the bushcrow is known to utter a low "keh" sound, and adults utter a deep "waw" while rubbing their bills together.<ref name="HBW609"/> ==Distribution and habitat== This species is [[endemic species|endemic]] to central-southern Ethiopia.<ref name="Madge50">{{Harvnb|Madge|Burn|1994|p=50}}</ref> It lives in a small area circumscribed by the towns of [[Yabelo]], [[Borena Zone|Borena]], [[Mega, Ethiopia|Mega]], and [[Arero]] in [[Sidamo Province]], and settles in wildlife under protection within [[Yabelo Wildlife Sanctuary]] and [[Borana National Park]].<ref name="Madge123"/> Its total range covers about {{convert|2400|km2|sqmi|lk=on|sp=us}}.<ref name="Madge123"/> The Stresemann's bushcrow lives in flat savanna covered with mature [[acacia]] and ''[[Commiphora]]'' thornbushes.<ref name="HBW609"/> The bird prefers open short-grass savannas with scattered stands of these mature thornbushes.<ref name="HBW609"/> The soil must be deep and rich to support the bushcrow.<ref name="HBW609"/> It is most numerous when these stands are next to agricultural fields.<ref name="HBW609"/> For many years it was unknown why the species could be completely absent from areas of suitable habitat near seemingly identical but inhabited land.<ref name="Madge123"/> However recent research has revealed that the bird appears to inhabit an area with a very precise average temperature extreme, all of the seemingly suitable but uninhabited surrounding lands actually have a slightly higher average temperature that appears to prevent the birds from successfully colonizing.<ref>{{cite web|url=http://www.birdlife.org/community/2012/03/scientists-discover-an-invisible-barrier-that-holds-the-answer-to-one-of-natures-little-mysteries/ |title=Scientists discover an 'invisible barrier' that holds the answer to one of nature's little mysteries &#124; BirdLife Community |publisher=Birdlife.org |date=2012-03-16 |access-date=2012-11-13}}</ref><ref>{{cite journal | author1= Bladon, A.J. |author2= Donald, P.F. | author3= Jones, S.E.I. | author4= Collar, N.J. | author5= Deng, J. |author6= Dadacha, G. | author7= Abebe, Y.D. |author8= Green, R.E. | year=2019 | title= Behavioural thermoregulation and climatic range restriction in the globally threatened Ethiopian Bush‐crow ''Zavattariornis stresemanni''| journal=Ibis| volume=161| pages = 546–558| doi= 10.1111/ibi.12660| issue=3| doi-access= free }}</ref> It is also not found near the scattered broadleaf woodland made up of ''[[Combretum]]'' and ''[[Terminalia (plant)|Terminalia]]''.<ref name="HBW609"/> Its habitat is between {{convert|1300|and|1800|m|ft|sp=us}} above sea level.<ref name="HBW609"/> ==Ecology and behavior== The Stresemann's bushcrow is normally found in groups of about six birds.<ref name="Madge123"/> This species does not migrate.<ref name="HBW609"/> ===Diet=== The bushcrow feeds both on the ground and in trees.<ref name="Madge123"/> It begins foraging at sunrise.<ref name="HBW609"/> While foraging, a bushcrow can be alone, in a pair, or in a group of six or seven other bushcrows.<ref name="HBW609"/> A foraging bushcrow digs vigorously in the soil while its beak is held slightly open to catch any insects it unearths.<ref name="HBW609"/> When it catches something, it carries it to the nearest tree or bush, pins it down with its foot, and kills and eats the prey.<ref name="HBW609"/> This species has also been seen using its beak to tear apart rotten wood and inspecting cattle dung in the search for food.<ref name="HBW609"/> It may also land on the backs of cattle to search for parasites.<ref name="HBW609"/> It can also chase flying insects, which it does on foot, abruptly changing direction and taking flying leaps after its prey.<ref name="HBW609"/> It often mixes with [[white-crowned starling]]s, [[red-billed hornbill]]s, [[red-billed buffalo weaver]]s, and [[superb starling]]s while foraging.<ref name="HBW609"/> When hunting in the trees, it is capable of walking atop horizontal branches and jumping upwards towards the crown, then descending in a glide from the crown to the ground.<ref name="HBW609"/> It eats primarily invertebrates and specifically insects, including [[termite]]s.<ref name="Madge123"/> Larvae and pupae, especially of ''[[Coeloptera]]'' moths, are eaten as well as the adults.<ref name="HBW609"/> ===Reproduction=== The Stresemann's bushcrow nests either alone or in a small, loosely connected colony of three to five nests.<ref name="HBW609"/> It is monogamous and may form a lifelong pair bond.<ref name="HBW609"/> The bushcrow occasionally has a third bird, or in rare cases two to four more, help the breeding couple both build the nest and care for the young.<ref name="HBW609"/> The helpers may also not be restricted to helping one nest at a time, as they have been seen at nests across the loose colonies.<ref name="HBW609"/> Allofeeding and allopreening, where the birds feed or preen each other, takes place both between the pair and with the other bushcrows in the colony.<ref name="HBW609"/> The bushcrow lays its eggs shortly after the first rains, which normally occur in late February and early March, leading to its eggs being laid in late March and early April.<ref name="HBW609"/> The nest is an untidy globular structure, on which the roof tapers to a point that has an opening into the interior chamber.<ref name="Madge123"/> The nest is {{convert|60|cm|in|sp=us}} in diameter while the interior chamber is {{convert|30|cm|in|sp=us}} across.<ref name="Madge123"/> To start constructing the nest, a single twig is inserted into the top of an [[acacia]] tree {{convert|5|to|6|m|ft|sp=us}} above the ground.<ref name="Madge123"/> This leads to the paired bushcrows becoming excited, engorging their blue facial skin.<ref name="HBW609"/> Almost ritualistically the pair then pick the acacia's leaves and twigs, dropping them to the ground.<ref name="HBW609"/> The pair end this display by chasing each other through the trees before continuing construction.<ref name="HBW609"/> The nest is made out of thorny twigs while the interior chamber is lined with dry grass and dried cattle dung.<ref name="Madge123"/> Damp soil is used to keep the initial twigs connected.<ref name="HBW609"/> Old nests are repaired and reused.<ref name="HBW609"/> Up to six eggs are laid in the nest.<ref name="Madge123"/> The bushcrow's eggs are cream-colored with pale lilac blotches that concentrate into a ring at the wider end.<ref name="Madge123"/> ==Relationship with humans== Prior to modern settlement in villages, the nomadic indigenous peoples of Ethiopia provided easy hunting grounds for the bushcrow as they left loose, dung-covered soil behind as they moved their cattle.<ref name="HBW564">{{Harvnb|dos Anjos|Debus|Madge|Marzluff|2009|p=564}}</ref> This provided a rich abundance of beetle larvae for the bushcrow to feed upon.<ref name="HBW564"/> ===Conservation=== Changes in the grazing habits of Ethiopia's indigenous peoples following the recent trend of settling in permanent villages have negatively impacted the Stresemann's bushcrow.<ref name="HBW564"/> While previously grazers left the soil loose and covered in dung to support the bushcrow's prey, this new lifestyle has resulted in overgrazing and soil compaction in some areas.<ref name="HBW564"/> The idea of private land ownership has also led to intensive planting of cash crops such as [[maize]].<ref name="HBW609"/> The rich soil that the species needs to forage is also prime farming land.<ref name="HBW609"/> In the [[Yabello Wildlife Sanctuary]], acacia trees are being collected for firewood, removing the bushcrow's nesting site.<ref name="HBW564"/> While protected under law, this sanctuary has difficulties enforcing the law.<ref name="HBW609"/> It is believed that between 1999 and 2003 the population of the bushcrow declined by 80%.<ref name="HBW564"/> The IUCN Red List of Threatened Species lists the Stresemann's bushcrow as endangered because of its very restricted range and loss of suitable habitat. The population seems to be declining rapidly and in 2007 it was estimated that there might be fewer than 10,000 birds remaining. <ref name=IUCN2012/> ==== Climate change ==== Due to its extremely unusual and specific temperature requirements, the Stresemann's bushcrow is considered one of the most threatened birds by [[climate change]]; climate change is predicted to reduced its range by 90% by 2070 in even the best-case scenarios (occupied range can often overestimate the number of individuals occupying the range, so the estimated population reduction may be even more than 90%), dramatically increasing the risk of extinction, with worse scenarios leading to total extinction in the wild. A similar outcome is predicted for the [[white-tailed swallow]] (''Hirundo megaensis''), which shares the same habitat and likely similar requirements, although the estimated range reduction is much lower for the swallow. Both species may be the only examples of warm-blooded animals whose range is fully driven by the climate. Intensive conservation such as [[captive breeding]] and [[Assisted colonization|assisted migration]] may be necessary to preserve the Stresemann's bushcrow. The birds and their projected decline may be used as [[Bioindicator|indicator species]] for climate change, allowing them to test the reliability of habitat models for other threatened animals. Both may also serve as [[flagship species]] for the impacts of climate change on avian diversity in Africa.<ref name=":0">{{Cite journal|last1=Bladon|first1=Andrew J.|last2=Donald|first2=Paul F.|last3=Collar|first3=Nigel J.|last4=Denge|first4=Jarso|last5=Dadacha|first5=Galgalo|last6=Wondafrash|first6=Mengistu|last7=Green|first7=Rhys E.|date=2021-05-19|title=Climatic change and extinction risk of two globally threatened Ethiopian endemic bird species|journal=PLOS ONE|language=en|volume=16|issue=5|pages=e0249633|doi=10.1371/journal.pone.0249633|pmid=34010302|pmc=8133463|bibcode=2021PLoSO..1649633B |issn=1932-6203|doi-access=free}}</ref><ref>{{Cite web|title=Monitoring species condemned to extinction may help save others as global temperatures rise|url=https://phys.org/news/2021-05-species-condemned-extinction-global-temperatures.html|access-date=2021-05-20|website=phys.org|language=en}}</ref> ==References== {{Reflist}} ===Cited texts=== * {{cite encyclopedia | last1 = dos Anjos| first1 = Luiz |first2= Stephen |last2=Debus |first3=Steve |last3=Madge |first4= John |last4=Marzluff | editor-last = del Hoyo | editor-first = Josep | editor2-last = Elliott | editor2-first =Andrew | editor3-last = Christie | editor3-first =David | title = Family Corvidae (Crows) | encyclopedia = [[Handbook of the Birds of the World]] | volume = 14. Bush-shrikes to Old World Sparrows | publisher = Lynx Editions | location = Barcelona | year = 2009 | isbn = 978-84-96553-50-7}} * {{cite book | last1 = Fry | first1 = C. Hilary |first2=Stuart |last2=Keith |first3=Emil K. |last3=Urban | title = The Birds of Africa Volume VI | publisher = Academic Press| year = 2000 | location = London | isbn =0-12-137306-1}} * {{cite book | last1 = Madge | first1 = Steve |first2=Hilary |last2=Burn | title = Crows and Jays: A Guide to the Crows, Jays, and Magpies of the World | publisher = Houghton Mifflin Company| year = 1994| location = Boston | isbn =0-395-67171-X}} ==Further reading== * Gedeon, Kai (2006) Observations on the biology of the Ethiopean Bush Crow ''Zavattariornis stresemanni'' ''[[Bulletin of the African Bird Club]]'' Vol 13 No 2 pages 178 - 188 ==External links== * [http://ibc.lynxeds.com/species/stresemanns-bush-crow-zavattariornis-stresemanni Stresemann's bushcrow] from the Internet Bird Collection * [http://birdingonthe.net/imgs/disley/Stresemanns_Bush-crow.jpg Anthony Disley line drawing of Stresemann's bushcrow] {{Webarchive|url=https://web.archive.org/web/20030730215638/http://birdingonthe.net/imgs/disley/Stresemanns_Bush-crow.jpg |date=2003-07-30 }} *[http://www.birdlife.org/datazone/species/index.html?action=SpcHTMDetails.asp&sid=5747&m=0 BirdLife Species Factsheet] {{Corvidae|1}} {{Corvides|Co.|state=collapsed}} {{Taxonbar|from=Q416528}} [[Category:Corvidae|Stresemann's bushcrow]] [[Category:Endemic birds of Ethiopia]] [[Category:Birds described in 1938|Stresemann's bushcrow]]'