Some of the birds that could not compete with the honey creepers were successful living on other islands. state one reason why this could be possible

One reason why the other birds that couldn't compete with the honey creepers fared better on other islands is because the other islands didn't have the honey creepers. There was also enough food on the other islands for the other breeds of birds. The birds were also adapted to the other islands like the honey creepers were adapted to theirs. 

Iwould say overuse ( but not 100% sure ) in the u.s. we tend to overuse water by leaving it running, throwing it away, taking long showers, etc.

The casefor proofs