Hi Gary
I don't know what your shooting conditions were. So I can only make a guess about the highlights. It is probably related to the strength of light when you shot those images. As I can see better from the wren image that the image was most probably shot at day time when the light is harsh. So, it might be a good idea to shoot early in the morning or late afternoon when the light is softer.
Also , I think you already use continuous shooting mode for the moving objects. So, why not trying some bracketed shots to obtain different exposures to choose the best pose and exposure
By the way, I'm not a bird shooter and bird shooters might give better advice than me