You Do Need power plug adapter while traveling from Costa Rica 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 Costa Rica are A and B. This is how they look like.

Costa Rica

In Costa Rica, outlets of type A and B are in use.

Type A

Type B

Niger

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

Type C

Type D

Type E

Type F