I observed this bird for over a year. Being a ground forager, the mandible was a great tool for turning over leaves and digging into the sediment that covered the forest floor. If you look closely, you can see the dirt on the end of the mandible. The bird seemed to have no trouble eating. Actually, the mandible worked so well for this bird, I'm wondering if it is an evolutionary prototype. I am going to observe the Brown Thrashers and see if there are offspring that may share the same mandible shape. Probably not, but who knows? I'll keep you posted.