A survey is needed to back up but I think most folks loosing birds to hawks have flocks made up of females only or juveniles. Bantams seem to make prime targets regardless of age or gender. I have red jungle fowl that are just slightly larger than bantams but much faster and smarter than bantams, yet hawks have a relatively easy time catching males. My games which are otherwise very similar to red jungle fowl yet are relatively resistant to hawk depredation. Size is part of difference but I have yet to see red jungle fowl (RJF) even threaten a male Coopers hawk which is similar in size as game is to a much larger female Coopers hawk.