Brood parasitism is found in what?

Character displacement takes place when there is

$A$ cuckoo laying eggs in the nest of other species of birds is an example of

Two butterfly species are competing for the same nectar of a flower in a garden. To survive and coexist together,they may avoid competition in the same garden by:

The principle of competitive exclusion was stated by

Animals eating plants are categorised separately as $A$,they are in a broad ecological context,not very different from $B$. Choose the correct option for $A$ and $B$.