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The Descent of Man

The Descent of Man

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more or less completely. Here protection can<br />

hardly have come into play. Mr. Blyth informs<br />

me that the females <strong>of</strong> Oriolus melanocephalus<br />

and <strong>of</strong> some allied species, when sufficiently<br />

mature to breed, differ considerably in plumage<br />

from the adult males; but after the second or<br />

third moults they differ only in their beaks<br />

having a slight greenish tinge. In the dwarf<br />

bitterns (Ardetta), according to the same authority,<br />

"the male acquires his final livery at the<br />

first moult, the female not before the third or<br />

fourth moult; in the meanwhile she presents an<br />

intermediate garb, which is ultimately exchanged<br />

for the same livery as that <strong>of</strong> the male." So<br />

again the female Falco peregrinus acquires her<br />

blue plumage more slowly than the male. Mr.<br />

Swinhoe states that with one <strong>of</strong> the Drongo<br />

shrikes (Dicrurus macrocercus) the male, whilst<br />

almost a nestling, moults his s<strong>of</strong>t brown plumage<br />

and becomes <strong>of</strong> a uniform glossy greenish-black;<br />

but the female retains for a long<br />

time the white striae and spots on the axillary

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