Wait a minute
When did the Mockiwi has a big resemblance with a Kiwi? Well, in that case it may be based on a Kiwi but i don't think it has a resemblance with that bird, like, i don't know what types of Kiwi were found but usually if i'm not wrong their beaks are more long not like of a duck. – Blower Pot (Talk page | Contributions | Pikmin Fanon)
About the English naming...
While I won’t deny the possibility of the mock in Mockiwi alluding to its resemblance of a kiwi, a part of me feels that the “Mock” could also be taken from the real life Mockingbird