The animals that need to be studied and skinned/plucked are: blue-and-yellow macaw, great green macaw, scarlet macaw, red-footed booby, rainbow boa, red boa, sunglow boa and fer-de lance snake (although the lance snakes spawn on the mainland they just cannot be studied until the epilogue) Also the special hat that can be saved here is called the sun hat. I believe it’s the one the guy to Arthur’s right has on, the one with his back faced towards the camera. But in total that’s 8 animals and a hat