চৰাই: বিভিন্ন সংশোধনসমূহৰ মাজৰ পাৰ্থক্য

চৰাইৰ প্লুমেজ অৰ্থাৎ পাখিৰ ৰং, বিন্যাস (arrangement) আৰু সজ্জা (pattern) নিয়মীয়াকৈ সলনি (moult) কৰে৷ প্ৰজননৰ পিছত চৰাইৰ প্লুমেজ সলনি হ'লে ইয়াক 'non-breeding" plumage বুলি কোৱা হয়৷<ref>{{Cite journal|last=Humphrey |first=Philip S. |date=1 June 1959|title=An approach to the study of molts and plumages |journal=The Auk |volume=76 |pages=1–31 |url=http://elibrary.unm.edu/sora/Auk/v076n01/p0001-p0031.pdf |format=PDF |issue=1 |jstor=4081839|last2=Parkes|first2=K. C.}}</ref> সাধাৰণতে প্ৰয়ভাগ চৰাইৰ ক্ষেত্ৰত 'Moulting' বছৰেকত এবাৰ হয়৷ অৱশ্যে কিছুমান প্ৰজাতিৰ ক্ষেত্ৰত ই বছৰত দুবাৰ আৰু ডাঙৰ আকাৰৰ মাংসভোজী চৰাই (birds of prey)ৰ ক্ষেত্ৰত ই কেইবাবছৰৰ মূৰত এবাৰকৈ হয়৷ Moulting patterns vary across species. In passerines, [[flight feather]]s are replaced one at a time with the innermost primary being the first. When the fifth of sixth primary is replaced, the outermost tertiaries begin to drop. After the innermost tertiaries are moulted, the secondaries starting from the innermost begin to drop and this proceeds to the outer feathers (centrifugal moult). The greater primary coverts are moulted in synchrony with the primary that they overlap.<ref name="pettingill">{{Cite book|author=Pettingill Jr. OS|year=1970|title=Ornithology in Laboratory and Field|isbn=808716093|publisher=Burgess Publishing Co}}</ref> A small number of species, such as ducks and geese, lose all of their flight feathers at once, temporarily becoming flightless.<ref name="debeeretal">de Beer SJ, Lockwood GM, Raijmakers JHFS, Raijmakers JMH, Scott WA, Oschadleus HD, Underhill LG (2001). [http://web.uct.ac.za/depts/stats/adu/ringmanual.htm Web.uct.ac.za] SAFRING Bird Ringing Manual.</ref> As a general rule, the tail feathers are moulted and replaced starting with the innermost pair.<ref name="pettingill"/> Centripetal moults of tail feathers are however seen in the [[Phasianidae]].<ref>{{Cite journal|last=Gargallo|first=Gabriel|date=1 June 1994|title=Flight Feather Moult in the Red-Necked Nightjar ''Caprimulgus ruficollis'' |journal=Journal of Avian Biology |volume=25|issue=2|pages=119–24 |doi=10.2307/3677029 |issn=09088857 |jstor=3677029}}</ref> The centrifugal moult is modified in the tail feathers of [[woodpecker]]s and [[treecreeper]]s, in that it begins with the second innermost pair of feathers and finishes with the central pair of feathers so that the bird maintains a functional climbing tail.<ref name="pettingill"/><ref>{{Cite journal|last=Mayr |first=Ernst |year=1954|title=The tail molt of small owls |journal=The Auk |volume=71 |issue=2 |pages=172–78 |url=http://elibrary.unm.edu/sora/Auk/v071n02/p0172-p0178.pdf|format=PDF}}</ref> The general pattern seen in [[passerine]]s is that the primaries are replaced outward, secondaries inward, and the tail from center outward.<ref>{{Cite web|first=Robert B|last=Payne|title=Birds of the World, Biology 532|url=http://www.ummz.umich.edu/birds/resources/families_otw.html|publisher=Bird Division, University of Michigan Museum of Zoology|accessdate=20 October 2007}}</ref> Before nesting, the females of most bird species gain a bare [[brood patch]] by losing feathers close to the belly. The skin there is well supplied with blood vessels and helps the bird in incubation.<ref>{{Cite journal|last=Turner |first=J. Scott |year=1997 |title=On the thermal capacity of a bird's egg warmed by a brood patch |journal=Physiological Zoology |volume=70 |issue=4 |pages=470–80 |doi=10.1086/515854 |pmid=9237308 |month= July|issn=0031-935X}}</ref>