Lost Bird is a Mission on Spineworld. It is about P.O Fax losing his bird to Old Leaf and he wants you to collect some leaves in order to then collect the bark of the old Jooula root and seeds of the Sula plant.
Old Leaf will give you a knife to dig out the leaves. Find a sparkle somewhere and use the knife to dig them out. Once you have the leaves, you then need to find the bark and the seeds. The first sparkle (the seed) is in the Temple Gardens at the bottom of the pink curly flower on the left. The second spark is at the Meyan temple on your top right on the big green root. Walk next to it and it will sparkle. Cut it out using the knife and put it inside a leaf. When you have found all of the bark and the seeds, put them into the leaves using your inventory. Take them back to Old Leaf.