[[File:Reed warbler cuckoo.jpg|thumb|upright|right|alt= Small brown bird places an insect in the bill of much larger grey bird in nest| ৰিড ৱাৰ্বলাৰ ([[:en:Reed Warbler|Reed Warbler]] raisingনামৰ aচৰাইবিধে উমনি পৰাজীৱী কেতেকী চৰাই ([[:en:Common Cuckoo|Common Cuckoo]],)ৰ aএটা [[broodপোৱালী parasite]].ডাঙৰ কৰিছে]]
[[Brood parasitism]], in which an egg-layer leaves her eggs with another individual's brood, is more common among birds than any other type of organism.<ref name = "brood">Davies N (2000). ''Cuckoos, Cowbirds and other Cheats''. [[T. & A. D. Poyser]]: London ISBN 0-85661-135-2</ref> After a parasitic bird lays her eggs in another bird's nest, they are often accepted and raised by the host at the expense of the host's own brood. Brood parasites may be either ''obligate brood parasites'', which must lay their eggs in the nests of other species because they are incapable of raising their own young, or ''non-obligate brood parasites'', which sometimes lay eggs in the nests of [[conspecific]]s to increase their reproductive output even though they could have raised their own young.<ref>{{cite journal | doi = 10.1093/beheco/8.2.153 | last1 = Sorenson | first1 = M | year = 1997 | title = Effects of intra- and interspecific brood parasitism on a precocial host, the canvasback, ''Aythya valisineria'' | url = http://beheco.oxfordjournals.org/cgi/reprint/8/2/153.pdf | journal = Behavioral Ecology | volume = 8 | issue = 2| pages = 153–61 }}</ref> One hundred bird species, including [[honeyguide]]s, [[icterid]]s, [[estrildid finch]]es and [[Black-headed Duck|ducks]], are obligate parasites, though the most famous are the [[cuckoo]]s.<ref name = "brood"/> Some brood parasites are adapted to hatch before their host's young, which allows them to destroy the host's eggs by pushing them out of the nest or to kill the host's chicks; this ensures that all food brought to the nest will be fed to the parasitic chicks.<ref>{{cite journal| last1=Spottiswoode| first1=C. N.| last2=Colebrook-Robjent| first2=J. F.R.| title=Egg puncturing by the brood parasitic Greater Honeyguide and potential host counteradaptations| journal=Behavioral Ecology| volume=18| pages=792| year=2007| doi=10.1093/beheco/arm025| issue=4}}</ref>
উমনি পৰজীৱিতা ([[:en:Brood parasitism|Brood parasitism]] নামৰ পৰিঘটনাটো বহুতো চৰাইৰ কএত্ৰত দেখা যায়৷ এই ক্ষেত্ৰত চৰায়ে আন প্ৰজাতিৰ চৰাইৰ বাহত কণী পাৰে আৰু আনৰ হতুৱাই পোৱালীক ডাঙৰ কৰোৱায়৷ <ref name = "brood">Davies N (2000). ''Cuckoos, Cowbirds and other Cheats''. [[T. & A. D. Poyser]]: London ISBN 0-85661-135-2</ref> যাৰ বাহত উমনী পৰজীৱীয়ে কণী পাৰে সেই চৰাইটোৱে কণীটো চিনিব নোৱাৰি নিজৰ আনবোৰ কণীৰ দৰেই উমনি দিয়ে৷ উমনি পৰজীৱীতা দেখা পোৱাৰ প্ৰধান কাৰণ বোৰৰ ভিতৰত নিজে বাহ সাজি কণী উমনি দিয়াত অক্ষমতা, আনৰ বাহতো পোৱালী জগাই প্ৰজনন অধিক সফল কৰাৰ উদেশ্য হ'ব পাৰে৷ <ref>{{cite journal | doi = 10.1093/beheco/8.2.153 | last1 = Sorenson | first1 = M | year = 1997 | title = Effects of intra- and interspecific brood parasitism on a precocial host, the canvasback, ''Aythya valisineria'' | url = http://beheco.oxfordjournals.org/cgi/reprint/8/2/153.pdf | journal = Behavioral Ecology | volume = 8 | issue = 2| pages = 153–61 }}</ref> উমনী পৰজীৱীসমূহৰ ভিতৰত কুলি চৰায়ে আটাইতকৈ বেছি জনাজাত যদিও এনে এশৰো অধিক প্ৰজাতি পোৱা যায়৷ <ref name = "brood"/>
