ACTIVITY 166:Read the text below and
think of the word which best fits each gap. Use only one word in each gap.
Then check the correct answers.
THOSE SMART BIRDS
The cuckoo is is called a brood parasite. In
words, it its eggs in the nests of other
birds, which as foster parents to the young
cuckoos.
Although the eggs of the various
host species include a number of different colours and
patterns, there is always a similarity in appearance
between the cuckoo's eggs and of the host.
A female cuckoo normally deposits only one of its eggs
in each host nest and takes away of the host's, sure that the same number will
remain there were in the first
. If birds notice a strange egg in
the they either build another nest on
of the first, or else with the problem by getting
of the strange egg.
But cuckoos rarely make the of leaving their eggs in a nest
that to the wrong host, where they
would be recognized. We do not know the cuckoo learns to distinguish
suitable nests but it seems to be the result of a
process that place while the female cuckoo is
being up by foster parents.
The remarkable feature of the process
is that so cuckoo eggs are lost, only 8% of
the total.
