Precisely the point, they can. Bigger is not always better. Case and point: Male lions are much bigger then females but it is the females that do the majority of the hunting. This is because the male lions are to large to catch most of their pray. Size is not always an advantage. This is also the reason why certain large creatures died out, if you can't catch the food you have no chance of life.
Other thanit being a glider, and not a flyer....I dont see how birds are more evolved than this creature.
I'd say this creature would be at the top of the food chain of the birds, if the birds weren't able to fly away from it.
that bird i heard off was found like 2 years ago and now you find out???