The birds going up above 20.000 ft are not that many (i.e. Condors, Vultures, Canadian Geese ) all fairly big an heavy ( Vultures around 4-5 Kg , Geese 5-9 Kgs and condors up to 15 Kg ) .
These kind of weights at 900 Km/h hitting the ( plastic) radome would end up on the knees of the crew I think.
I would also normally leaves some blood traces.