One result of this immunity is that
humming-birds are excessively numerous, albeit such slow breeders; for,
as we have seen, they only lay two eggs, and not only so, but the second
egg is often dropped so long after incubation has begun in the first
that only one is really hatched. Yet Belt expressed the opinion that in
Nicaragua, where he observed humming-birds, they out-numbered all the
other birds together. Considering how abundant birds of all kinds are in
that district, and that most of them have a protective colouring and lay
several eggs, it would be impossible to accept such a statement unless
we believed that humming-birds have, practically, no enemies.
Another result of their immunity from persecution is the splendid
colouring and strange and beautiful feather ornaments distinguishing
them above all other birds; and excessive variation in this direction is
due, it seems to me, to the very causes which serve to check variation
in all other directions. In their plumage, as Martin long ago wrote,
nature has strained at every variety of effect and revelled in an
infinitude of modifications. How wonderful their garb is, with colours
so varied, so intense, yet seemingly so evanescent!--the glittering
mantle of powdered gold; the emerald green that changes to velvet black;
ruby reds and luminous scarlets; dull bronze that brightens and burns
like polished brass, and pale neutral tints that kindle to rose and
lilac-coloured flame.
Pages:
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222