cuckoo - brood parasites

カッコーは托卵する鳥として知られていますが、カッコーが生んだ雛を托卵された鳥はよく騙されてカッコーの雛を育てるのか不思議に思っていましたが、Richard DawkinsのThe Selfish Geneを読んでいたらその答えが書かれていました。
I think that cuckoo nestlings must be doing rather more than just 'fooling' their hosts, more than just pretending to be something that they aren't. They seem to act on the host's nervous system in rather the same way as an addictive drug. This is not so hard to sympathize with, even for those with no experience of addictive drugs. A man can be aroused, even to erection, by a printed photograph of a woman's body. He is not 'fooled' into thinking that the pattern of printing ink really is a woman. He knows that he is only looking at ink on paper, yet his nervous system responds to it in the same kind of way as it might respond to a real woman.
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So enticing is the red gape of a cuckoo nestlig that it is not uncommon for to see a bird dropping food into the mouth of a baby cuckoo sitting in some other bird's nest!
雛が大きな黄色い口を開けているのを見ると親鳥は餌を与えずにはいられないのと、人間の男が女性の裸の写真を見て興奮するのはどちらも同じく神経システムに作用しているからで、騙されていると分かっていても反応せざるを得ない生物の不思議な性質なのですね。
カッコーが托卵することの説明はWikipediaに書かれています。
Wikipedia: Some species are brood parasites, laying their eggs in the nests of other species, but the majority of species raise their own young.