[DoctorBeaver (OP)]

I heard that if you pluck the 2 end feathers from a goose's wings, it can't fly. Is that true? If so, is it true of all birds? And what is so special about those feathers?

[another_someone]

Don't know if it is true or not, but I would guess that the end feathers would act a bit like winglets on many modern aircraft, and are used to control wingtip vortexes.