brid isation ▁may ▁occur ▁when ▁they ▁are ▁both ▁conf ined ▁within ▁the ▁same ▁area . ▁The ▁resulting ▁off spring ▁are ▁usually ▁fert ile . ▁A ▁study ▁of ▁these ▁hy brid ▁animals ▁at ▁Sp io enk op ▁Dam ▁Nature ▁Reserve ▁in ▁South ▁Africa ▁revealed ▁that ▁many ▁had ▁dis adv antage ous ▁ab normal ities ▁rel ating ▁to ▁their ▁teeth , ▁horn s , ▁and ▁the ▁w orm ian ▁b ones ▁in ▁the ▁sk ull . ▁Another ▁study ▁reported ▁an ▁increase ▁in ▁the ▁size ▁of ▁the ▁hy brid ▁as ▁compared ▁to ▁either ▁of ▁its ▁parents . ▁In ▁some ▁animals , ▁the ▁tym pan ic ▁part ▁of ▁the ▁temporal ▁b one ▁is ▁highly ▁de formed , ▁and ▁in ▁others , ▁the ▁radius ▁and ▁ul na ▁are ▁f used . ▁ ▁Character istics ▁of ▁the ▁species ▁ ▁Both ▁species ▁of ▁w ilde be est ▁are ▁even - to ed , ▁horn ed , ▁grey ish - b rown ▁ung ul ates ▁res emb ling ▁cattle . ▁M ales ▁are ▁larger ▁than ▁females ▁and ▁both ▁have ▁heavy ▁for equ arters ▁compared ▁to ▁their ▁h ind quarters . ▁They ▁have ▁broad ▁m uzz les , ▁Roman ▁nos es , ▁and ▁sh ag gy ▁man es ▁and ▁t ails . ▁The ▁most ▁striking ▁morph ological ▁differences ▁between ▁the ▁black ▁and ▁blue ▁w ilde be est ▁are ▁the ▁orientation ▁and ▁curv ature ▁of ▁their ▁horn s ▁and ▁the ▁colour ▁of ▁their ▁co ats . ▁The ▁blue ▁w ilde be est ▁is ▁the ▁bigger ▁of ▁the ▁two ▁species . ▁In ▁males ,