MIMICRY IN BIRDS. 
By FRANK FINN, B.A., F.Z.S. 
Ee ees student of the theory of natural selection is familias with the wonderful 
+ cases in which some defenceless insect closely copies in its appearance a quite: 
unrelated form, which for some reason or other—objectionable taste or exceptional 
means of defence—appears to be more immune from attack than the majority ; but: 
the cases of this “mimicry,” as it. 
is called, among birds are not so: 
well known, and it is worth while 
here to review them in order to: 
be able to gain an idea as to how 
these remarkable resemblances came: 
about, in the case of birds at all 
events. 
The best-known instance of mimi-- 
ery in birds, and the one most usually 
quoted, is the resemblance between 
certain Orioles and Fmar-Birds in 
the islands of the Australian region. 
Friar-birds are large honey-suckers,. 
forming the genus Tvropidorhynchuws 
of ornithologists. They are not 
attractive In appearance, being of a. 
dull snuffy-brown colour, with some 
bare blackish skin about the eyes. 
They are, however, unusually well 
able to look after themselves. Being 
as big as blackbirds, with sharp, 
curved beaks and very strong feet 
and claws, and having besides a 
clannish disposition, they are inclined to band together and defend themselves against 
hawks and crows—are not, in short, the sort of quarry with which the average bird 
of prey cares to have to do. The orioles, on the other hand, are solitary birds with 
small weak feet, and bills which, though stout enough in their way, are not such 
efficient weapons as the nicely-curved and sharp-pointed bill of the friar-birds. 
Now in certain islands where both friar-birds and orioles occur, it is noticeable 
that the local orioles, although belongmg to a family which is usually brillant in 
colour, at any rate when adult, are of just the same quakerish shade as the 
honey-suckers living with them. More than that, where the fmar-bird shows a bald 
black patch round the eye, there the oriole will have a patch of dark feathers to 
match it; the friar-bird’s ruff or cowl of reversed feathers will be copied by a light 
patch on the oriole’s neck, and the high-ridged bill of one friar-bird is imitated by 
its corresponding oriole having a similar Roman nose.. The sum total of these 
remarkable resemblances is that the birds are so well-matched that naturalists getting’ 
hold of thei skins easily mistake the orioles for honey-suckers; I know I did myself 
when I first saw one of these “mimicking” orioles in a drawer full of oriole skins, 
thinking that some one who did not know his business had been confusing the 
collection I was inspecting; and many years ago a mimetic onole (Oriolus bowrwensis) 
374 
DRONGO, OR KING CROW. 
