Who is The Vultures from Dragon Bones: A Novel and what is their importance?

The vultures are a group of older museum curators. The curators seek the uncovered relics for their own museums. The curators are not corrupt, as many make them out to be, but rather, are simply doing their jobs. While generally smaller characters in the story, the Vultures do tell David and Hulan much of the background of Yu, as well as hint at the true identity of Ma.