Black rhino Black rhinos are critically endangered on the savannas of southwestern Africa and one bl

Black rhino

Black rhinos are critically endangered on the savannas of southwestern Africa and one black rhino subspecies is already extinct. Rhino horns are made of keratin, the same protein that makes your fingernails. They are extremely valuable on the black market (a ounce of rhino horn is worth more than an ounce of gold), for their uses in Eastern medicine and Middle Eastern ceremonial daggers. 

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