Hi I had four rheas that I have raised six chicks and were around 8 months old. Around a week ago I found one dead in the pasture. Nothing had seemed out of the ordinary and they are feed Mazuri crumbles. At the end of last week another one passed a way. Does any one have an idea of what might be wrong? They are fed crumbles, grapes, various greens and have an 8 acre pasture that they share with two 6 months Emus. I did notice in the last one it didn't eat the grapes nor eat her crumbles then was died. Any idea would be greatly appreciated as no one in the area has any knowledge or rheas.