There will be a picture of the statue in question in the Trapmaker’s journal, available in your quest item inventory. Instead, you’ll need to head down the titular valley on this island, just up from the beach where Salty is, and enter the cave beside the bird statue.
You’ll find it on Plunder Valley, so don’t jump straight back into your ship after you speak to Salty. The first task on your journey is to uncover the Rum Bottle Spyglass.
