Travel Reference
In-Depth Information
capes the attacks of its enemies. This is termed a 'protective resemblance.' If however the
butterfly, being itself a savoury morsel to birds, had closely resembled another butterfly
which was disagreeable to birds, and therefore never eaten by them, it would be as well pro-
tected as if it resembled a leaf; and this is what has been happily termed 'mimicry' by Mr.
Bates, who first discovered the object of these curious external imitations of one insect by
another belonging to a distinct genus or family, and sometimes even to a distinct order. The
clear-winged moths which resemble wasps and hornets are the best examples of 'mimicry'
in our own country.
For a long time all the known cases of exact resemblance of one creature to quite a differ-
ent one were confined to insects, and it was therefore with great pleasure that I discovered in
the island of Bouru two birds which I constantly mistook for each other, and which yet be-
longed to two distinct and somewhat distant families. One of these is a honeysucker named
Tropidorhynchus bouruensis, and the other a kind of oriole, which has been called Mimeta
bouruensis. The oriole resembles the honeysucker in the following particulars: the upper and
under surfaces of the two birds are exactly of the same tints of dark and light brown; the
Tropidorhynchus has a large bare black patch round the eyes; this is copied in the Mimeta
by a patch of black feathers. The top of the head of the Tropidorhynchus has a scaly appear-
ance from the narrow scale-formed feathers, which are imitated by the broader feathers of
the Mimeta having a dusky line down each. The Tropidorhynchus has a pale ruff formed of
curious recurved feathers on the nape (which has given the whole genus the name of Friar
birds); this is represented in the Mimeta by a pale band in the same position. Lastly, the bill
of the Tropidorhynchus is raised into a protuberant keel at the base, and the Mimeta has the
same character, although it is not a common one in the genus. The result is, that on a super-
ficial examination the birds are identical, although they have important structural differen-
ces, and cannot be placed near each other in any natural arrangement.
In the adjacent island of Ceram we find very distinct species of both these genera, and,
strange to say, these resemble each other quite as closely as do those of Bouru. The Tropido-
rhynchus subcornutus is of an earthy brown colour, washed with ochreish yellow, with bare
orbits, dusky cheeks, and the usual recurved nape-ruff. The Mimeta forsteni which accom-
panies it, is absolutely identical in the tints of every part of the body, and the details are
copied just as minutely as in the former species.
We have two kinds of evidence to tell us which bird in this case is the model, and which
the copy. The honeysuckers are coloured in a manner which is very general in the whole
family to which they belong, while the orioles seem to have departed from the gay yellow
tints so common among their allies. We should therefore conclude that it is the latter who
