| → OMIT 1869 1872 |
| species of cuckoo in the same 1866 |
|
| → OMIT 1869 1872 |
| or not domed 1866 |
|
| → in colour to 1869 1872 |
| to 1866 |
|
| → Had our cuckoo 1869 1872 |
| had she 1866 |
|
| ↑ 3 blocks not present in 1859 1860 1861 1866 1869; present in 1872 |
| In the case of the European cuckoo, the offspring of the foster-parents are commonly ejected from the nest within three days after the cuckoo is hatched; and as the latter at this age is in a most helpless condition, Mr. Gould was formerly inclined to believe that the act of ejection was performed by the foster-parents themselves.
But he has now received a trustworthy account of a young cuckoo which was actually seen, whilst still blind and not able even to hold up its own head, in the act of ejecting its foster-brothers.
One of these was replaced in the nest by the observer, and was again thrown out.
|
|
| → OMIT 1869 |
| last point insisted on— namely, of the 1866 |
|
|
birds generally lay only one egg in a nest, it is not rare to find two and even three eggs
the same
→OMIT
In the Bronze cuckoo the eggs vary greatly in size, from eight to ten lines in length. Now if it had been of
advantage to this species to have laid eggs even smaller than those now
so as to have deceived certain foster-parents, or, as is more probable, to have been hatched within
shorter period (for it is asserted that there is a relation between
size
and the period of
then there is no difficulty in believing that a race or species might have been formed which would have laid smaller and smaller eggs; for these would have been more safely hatched and reared. Mr. Ramsay remarks that two of the Australian cuckoos, when they lay their eggs in an open
→OMIT
nest, manifest a decided preference for nests containing eggs similar
→in colour to
their own. The European species
manifests some tendency towards a similar instinct, but not rarely departs from it, as is shown by her laying her dull and pale-coloured eggs in the nest of the Hedge-warbler with
bright greenish-blue
→Had our cuckoo
invariably displayed the above instinct, it would assuredly have been added to those which it is assumed must all have been acquired together. The eggs of the Australian Bronze cuckoo vary, according to Mr. Ramsay,
an extraordinary
in colour; so that in this respect, as well as in size, natural selection
might have secured and fixed any advantageous variation. ↑ |
| With
to the
→OMIT
young European cuckoo ejecting its
must first be remarked that Mr. Gould, who has paid particular attention to this subject, is convinced that the belief is an error; he asserts that the young foster-birds are generally ejected during the first three days, when the young cuckoo is quite
he maintains that
|
