The way I see it, a big aspect of conservation isn't just making laws to restrict poaching or habitat loss or whatever, but figuring out WHY those things exist in the first place. If you don't take those things to account, the new laws might not work very well.
The laws were passed to stop people from collecting the birds. As a result, people still collected the birds. It doesn't explain how passing the law caused the bird's extinction in the wild.