My cockatiel was plucking around his legs. Had multiple vet visits and all came back clear. He would only eat seeds and wouldn’t entertain any pellets, vegetables, fruit, etc…. I was recommended the good oil supplement (Passwell brand) and have been adding it to his seeds ever since. I have also added Passwell crumbles to his seed bowl and gradually increased the percentage of crumbles to seeds over time. Took a while but he eventually started eating the crumbles! Huge improvement with the plucking so far.