Wow it was the darn mosquitoes. [1] Looks like they are working on that. [1] [2] I had always assumed island extinctions for bird populations the culprits were primarily introduced rats and snakes for times when sailing ships were the main form of travel; both rats and feral cats in more recent times.
[1] https://economictimes.indiatimes.com/news/international/glob...
[2] https://greatergood.com/blogs/news/mosquitoes-in-hawaii (mosquito population reduction project )