Editing Alpine chough (section)

==Behaviour and ecology==

===Breeding===
[[File:Alpendohle Ei-3c.jpg|thumb|alt= A cream egg with light buff blotches|Eggs vary from cream to [[buff (colour)|buff]] to light-green, and have brown speckles.<ref name= Madge94/>]]
The Alpine chough is socially [[monogamy in animals|monogamous]], showing high partner fidelity in summer and winter and from year to year.<ref name= delestradesty>{{cite journal | last= Delestrade | first= Anne|author2=Stoyanov, Georgi | year= 1995| title= Breeding biology and survival of the Alpine Chough ''Pyrrhocorax graculus'' | journal= Bird Study | volume=42 | pages=222–231 | doi =10.1080/00063659509477171 | issue= 3 | doi-access= free | bibcode= 1995BirdS..42..222D}}</ref> Nesting typically starts in early May, and is non-colonial, although in suitable habitat several pairs may nest in close proximity.<ref name= Madge94/> The bulky nests are composed of roots, sticks and plant stems lined with grass, fine twiglets or hair, and may be constructed on ledges, in a cave or similar fissure in a cliff face, or in an abandoned building. The [[clutch (eggs)|clutch]] is 3–5 glossy whitish eggs, averaging {{convert|33.9|x|24.9|mm|in}} in size,<ref name= Harrison>{{cite book| last = Harrison | first = Colin James Oliver | title = A field guide to the nests, eggs and nestlings of European birds: with North Africa and the Middle East | year =1975 | publisher = Collins | isbn = 978-0-00-219249-1 |page = 316}}</ref> which are tinged with buff, cream or light-green and marked with small brown blotches;<ref name = Madge94/> they are incubated by the female for 14–21 days before hatching.<ref name = BWP/> The chicks hatch with a dense covering of natal [[down feather|down]] — in contrast to those of the red-billed chough, which are almost naked<ref name=agd>{{cite book|title=Avian growth and development. Evolution within the altricial precocial spectrum. |author1=Starck, J Matthias |author2=Ricklefs, Robert E. |year=1948 |publisher=Oxford University Press |location=New York |isbn=978-0-19-510608-4 |page=7 |url=http://sci.bio.lmu.de/morpho/downloads/agd1.pdf |archive-url=https://wayback.archive-it.org/all/20081216211957/http://sci.bio.lmu.de/morpho/downloads/agd1.pdf |url-status=dead |archive-date=16 December 2008 }}</ref> — and [[fledge]] 29–31 days from hatching.<ref name = BWP/> The young birds are fed by both parents, and may also be fed by other adults when they have fledged and joined the flock.<ref name = Madge94/> Breeding is possible in the high mountains because chough eggs have fewer pores than those of lowland species, reducing loss of water by evaporation at the low atmospheric pressure.<ref>{{cite journal | last= Rahn | first=H. |author2=Ar, A. | s2cid=27372255 | year= 1974 | title= The avian egg: incubation time and water loss | journal= The Condor | volume=76 | issue = 2 | pages= 147–152| doi =10.2307/1366724 | jstor = 1366724 }}</ref> The [[embryo]]s of bird species that breed at high altitude also have [[haemoglobin]] with a genetically determined high affinity for oxygen.<ref>{{cite journal | last= Black | first= Craig Patrick |author2=Snyder, Gregory K | year= 1980 | title= Oxygen transport in the avian egg at high altitude | journal= American Zoologist | volume= 20 | issue =2 | pages= 461–468 | doi = 10.1093/icb/20.2.461 | doi-access= free }}</ref>

In the western Italian Alps, the Alpine chough nests in a greater variety of sites than red-billed chough, using natural cliffs, pot-holes and abandoned buildings, whereas the red-billed uses only natural cliffs (although it nests in old buildings elsewhere).<ref name=Madge94/><ref name= Rolando2/><ref name= Blanco5>{{cite journal|last= Blanco |first= Guillermo |author2= Fargallo, Juan A.|author3= Tella, José Luis Cuevas |author4= Jesús A. |date=February–March 1997 |title= Role of buildings as nest-sites in the range expansion and conservation of choughs ''Pyrrhocorax pyrrhocorax'' in Spain |journal=Biological Conservation |volume= 79 |issue=2–3 |pages=117–122 | doi=10.1016/S0006-3207(96)00118-8|bibcode= 1997BCons..79..117B |url=https://digital.csic.es/bitstream/10261/58104/1/Bc12.pdf |hdl= 10261/58104 |hdl-access= free }}</ref> The Alpine chough lays its eggs about one month later than its relative, although breeding success and reproductive behaviour are similar. The similarities between the two species presumably arose because of the same strong environmental constraints on breeding behaviour.<ref name= Rolando2/>

A study of three different European populations showed a mean clutch size of 3.6 eggs, producing 2.6 chicks, of which 1.9 fledged. Adult survival rate varied from 83 to 92%, with no significant difference detected between males and females. Survival of first-year birds was, at 77%, lower than that of adults. The availability or otherwise of human food supplied from tourist activities did not affect breeding success.<ref name= delestradesty/>

===Feeding===
[[File:Pyrrhocorax graculus -Gornergrat Observatory, Switzerland -alps-8.jpg|alt= Visitors sitting at tables on a large balcony high in the Swiss Alps, and a chough is perching on a railing beside them.|A chough probably looking for supplementary food is perching on a railing alongside visitors to [[Gornergrat]], high in the Swiss Alps|thumb]]
In the summer, the Alpine chough feeds mainly on [[invertebrate]]s collected from pasture, such as [[beetle]]s (''[[Selatosomus aeneus]]'' and ''[[Otiorhynchus morio]]'' have been recorded from [[Pellet (ornithology)|pellets]]), [[snail]]s, [[grasshopper]]s, [[caterpillar]]s and [[fly]] [[larva]]e.<ref name= goodwin/> The diet in autumn, winter and early spring becomes mainly fruit, including [[berry|berries]] such as the European Hackberry (''[[Celtis australis]]'') and Sea-buckthorn (''[[Sea-buckthorn|Hippophae rhamnoides]]''),<ref name= goodwin/> [[rose hip]]s, and domesticated crops such as apples, grapes and pears where available.<ref name= LaioloCarisio/> It has been observed eating flowers of ''[[Crocus vernus|Crocus vernus albiflorus]]'', including the [[Gynoecium|pistils]], perhaps as a source of [[carotenoid]]s.<ref name= BCbirds>{{cite journal | last= McKibbin | first= René |author2=Bishop, Christine A. | year= 2008 | title= Feeding observations of the western Yellow-breasted Chat in the south Okanagan valley British Columbia, Canada during a seven-year study period | journal= British Columbia Birds | volume=18 | pages= 24–25 | url = http://bcfo.files.wordpress.com/2012/11/bcbvol18j.pdf}}</ref> The chough will readily supplement its winter diet with food provided by tourist activities in mountain regions, including ski resorts, [[landfill|refuse dump]]s and [[picnic|picnic areas]]. Where additional food is available, winter flocks are larger and contain a high proportion of immature birds. The young birds principally frequent the sites with the greatest food availability, such as refuse dumps.<ref name= Delestrade>{{cite journal | last= Delestrade | first= Anne | year= 1994| title= Factors affecting flock size in the Alpine Chough ''Pyrrhocorax graculus'' | journal= Ibis | volume= 136 | pages= 91–96 | doi =10.1111/j.1474-919X.1994.tb08135.x }}</ref> Both chough species will hide food in cracks and fissures, concealing the cache with a few pebbles.<ref name= wall>{{cite book | last = Wall | first = Stephen B. Vander | title = Food hoarding in animals | year = 1990 | publisher = University of Chicago Press | isbn = 978-0-226-84735-1 | page = [https://archive.org/details/foodhoardinginan0000vand/page/306 306] | url = https://archive.org/details/foodhoardinginan0000vand/page/306 }}</ref>

This bird always forages in groups, which are larger in winter than summer, and have constant composition in each season. Where food resources are restricted, adults dominate young birds, and males outrank females.<ref name= delestradesty/> Foraging areas change altitudinally through the year, depending on climatic factors, food availability and food quality. During the breeding season, birds remain above the [[tree line]], although they may use food provided by tourists at refuges and picnic areas.<ref name= LaioloCarisio/>

Movement to lower levels begins after the first snowfalls, and feeding by day is mainly in or near valley bottoms when the snow cover deepens, although the birds return to the mountains to roost. In March and April the choughs frequent villages at valley tops or forage in snow-free patches prior to their return to the high meadows.<ref name=LaioloCarisio>{{cite journal|last=Laiolo |first=Paola |author2=Rolando, Antonio |author3=Carisio, Lorendana |title=Winter movements of the Alpine Chough: implications for management in the Alps |journal=Journal of Mountain Ecology |volume=6 |pages=21–30 |url=http://www.mountainecology.org/IBEX6/pdf/LAIOLO.pdf |date=2001 |url-status=dead |archive-url=https://web.archive.org/web/20070705225109/http://www.mountainecology.org/IBEX6/pdf/LAIOLO.pdf |archive-date=5 July 2007 }}</ref> Feeding trips may cover {{convert|20|km|mi|abbr=on}} distance and {{convert|1600|m|ft|abbr=on}} in altitude. In the Alps, the development of skiing above {{convert|3000|m|ft|abbr=on}} has enabled more birds to remain at high levels in winter.<ref name = BWP/>

Where their ranges overlap, the two chough species may feed together in the summer, although there is only limited competition for food. An Italian study showed that the vegetable part of the winter diet for the red-billed chough was almost exclusively ''[[Gagea]]'' bulbs dug from the ground, whilst the Alpine chough took berries and hips. In June, red-billed choughs fed mainly on caterpillars whereas Alpine choughs ate [[Tipuloidea|crane fly]] [[pupa]]e. Later in the summer, the Alpine chough consumed large numbers of grasshoppers, while the red-billed chough added crane fly pupae, fly larvae and beetles to its diet.<ref name= Rolando2>{{cite journal|last= Rolando |first= Antonio |author2=Laiolo, Paola |date=April 1997 |title= A comparative analysis of the diets of the chough ''Pyrrhocorax pyrrhocorax'' and the alpine chough ''Pyrrhocorax graculus'' coexisting in the Alps |journal= Ibis | volume=139 |issue=2 |pages=388–395 |doi= 10.1111/j.1474-919X.1997.tb04639.x }}</ref> In the eastern Himalayas in November, Alpine choughs occur mainly in [[juniper]] forests where they feed on [[Juniper berry|juniper berries]], differing ecologically from the red-billed choughs in the same region and at the same time of year, which feed by digging in the soil of terraced pastures of villages.<ref>{{cite journal |author= Laiolo, Paola |year= 2003 |title= Ecological and behavioural divergence by foraging Red-billed ''Pyrrhocorax pyrrhocorax'' and Alpine Choughs ''P. graculus'' in the Himalayas |url= http://cat.inist.fr/?aModele=afficheN&cpsidt=15605736 |journal= Ardea |volume= 91 |issue= 2 |pages= 273–277 |access-date= 2 June 2009 |archive-date= 12 June 2012 |archive-url= https://web.archive.org/web/20120612070106/http://cat.inist.fr/?aModele=afficheN&cpsidt=15605736 |url-status= dead }} (abstract)</ref>

===Natural threats===
Predators of the choughs include the [[peregrine falcon]], [[golden eagle]] and [[Eurasian eagle-owl]], while the [[common raven]] will take nestlings.<ref name = birdwatchireland >{{cite web |title= A year in the life of Choughs |url= http://www.birdwatchireland.ie/Default.aspx?tabid=206 |publisher= Birdwatch Ireland |access-date= 6 February 2008 |archive-url= https://web.archive.org/web/20160411234509/http://www.birdwatchireland.ie/Default.aspx?tabid=206 |archive-date= 11 April 2016 |url-status= dead }}</ref><ref name = OperationChough>{{cite web|title= Know Your Crows |url= http://www.paradisepark.org.uk/choughs/crows.html |archive-url= https://web.archive.org/web/20140714160621/http://www.paradisepark.org.uk/choughs/crows.html |archive-date= 2014-07-14 |publisher= [[Operation Chough]] |access-date=5 July 2014}}</ref><ref name= Rolando >{{cite journal|last= Rolando |first= Antonio |author2= Caldoni, Riccardo|author3= De Sanctis, Augusto|author4= Laiolo, Paola |year= 2001|title= Vigilance and neighbour distance in foraging flocks of red-billed choughs, ''Pyrrhocorax pyrrhocorax'' |journal= Journal of Zoology|volume= 253|issue= 2| doi = 10.1017/S095283690100019X | pages= 225–232 }}</ref><ref name= Blanco>{{cite journal|last= Blanco |first= Guillermo |author2=Tella, José Luis |date=August 1997 |title= Protective association and breeding advantages of choughs nesting in lesser kestrel colonies |journal=Animal Behaviour |volume= 54|issue=2 |pages=335–342 | doi=10.1006/anbe.1996.0465 |pmid=9268465|url=https://www.researchgate.net/publication/223037430|hdl= 10261/58091 |s2cid= 38852266 |hdl-access=free }}</ref>
Alpine choughs have been observed diving at a Tibetan [[red fox]]. It seems likely that this "[[mobbing]]" behaviour may be play activity to give practice for when genuine defensive measures may be needed to protect eggs or young.<ref>{{cite journal| last= Blumstein | first= Daniel T.|author-link=Daniel T. Blumstein |author2=Foggin, J. Marc|date=March 1993 | title= Playing with fire? alpine choughs play with a Tibetan red fox | journal= Journal of the Bombay Natural History Society | volume= 90 | pages= 513–515 | url =https://biodiversitylibrary.org/page/48609784}}</ref>

The Alpine chough is a host of the widespread bird [[flea]] ''Ceratophyllus vagabunda'', two specialist chough fleas ''Frontopsylla frontalis'' and ''F.&nbsp;laetus'',<ref>{{cite book |title= Fleas, flukes and cuckoos. A study of bird parasites. |author= Rothschild, Miriam |author-link= Miriam Rothschild |author2=Clay, Theresa |author2-link=Theresa Clay |year= 1953 |publisher= Collins |location= London |pages= 89, 95 |url= https://archive.org/details/fleasflukescucko017900mbp }}</ref> a [[cestoda|cestode]] ''Choanotaenia pirinica'',<ref>(Russian) {{cite journal |author= Georgiev B. B. |author2= Kornyushin, VV.|author3= Genov, T. |year= 1987 |title= ''Choanotaenia pirinica'' sp. n. (Cestoda, Dilepididae), a parasite of ''Pyrrhocorax graculus'' in Bulgaria |journal= Vestnik Zoologii |volume= 3 |pages= 3–7 }}</ref> and various species of [[chewing louse|chewing lice]] in the genera ''[[Brueelia]]'', ''[[Menacanthus]]'' and ''Philopterus''.<ref>{{cite journal |author= Kellogg, V. L. |author2= Paine, J. H. |year= 1914 |title= Mallophaga from birds (mostly Corvidae and Phasianidae) of India and neighbouring countries |journal= Records of the Indian Museum |volume= 10 |pages= 217–243 |url= http://phthiraptera.info/content/mallophaga-birds-mostly-corvidae-and-phasianidae-india-and-neighbouring-countries |doi= 10.5962/bhl.part.5626 |s2cid= 81701158 |access-date= 22 February 2013 |archive-date= 27 January 2021 |archive-url= https://web.archive.org/web/20210127141706/http://phthiraptera.info/content/mallophaga-birds-mostly-corvidae-and-phasianidae-india-and-neighbouring-countries |url-status= dead }}</ref>