You Do Need power plug adapter while traveling from New Caledonia to Niger.

Here is Why You Need An Adapter

The outlet and plug type used in Niger are C, D, E and F and in New Caledonia are C and F. This is how they look like.

New Caledonia

In New Caledonia, outlets of type C and F are in use.

Type C

Type F

Niger

In Niger, outlets of type C, D, E and F are in use.

Type C

Type D

Type E

Type F