My guess is they want fewer mosquitos in addition to not having mosquitos that kill birds so kind of a two mosquitos one stone thing.

k00b

Guess they don't really want to keep those rare birds alive. More under their control.

Malachi17

conspiracy

Millions of Mosquitoes Released in Hawaii To Save Rare Bird

It looks like they are using [Wolbachia](https://en.wikipedia.org/wiki/Wolbachia) infected mosquitos but are only releasing males so that it kills off the existing population rather than replacing it. This is called the [Incompatible Insect Technique](https://www.worldmosquitoprogram.org/en/learn/how-our-method-compares):

> In this approach, mosquitoes are reared in laboratories that contain Wolbachia. They are sexed and then only males are released. When a Wolbachia infected male mosquito mates with a wild female mosquito without Wolbachia her eggs do not hatch. This has a similar effect as SIT and over time and with repeated releases the wild population should decline.