Tim Fitzharris / Hippopotamus (Hippopotamus amphibius) with mouth agape, Kenya

Fiona Rogers / Mantled Colobus (Colobus guereza) pair play fighting, Kakamega Forest Reserve, Kenya

Shin Yoshino / Hippopotamus (Hippopotamus amphibius) pair fighting in water, Masai Mara, Kenya

Suzi Eszterhas / Hippopotamus (Hippopotamus amphibius) mother with young calf showing aggressive behavior toward other hippo, Masai Mara National Reserve, Kenya

Suzi Eszterhas / Spotted Hyena (Crocuta crocuta) group scavenging carcass, Masai Mara Reserve, Kenya

Gerry Ellis / Black Rhinoceros (Diceros bicornis) males battling, Masai Mara National Reserve, Kenya

Shin Yoshino / Hippopotamus (Hippopotamus amphibius) pair fighting, Masai Mara, Kenya

Gerry Ellis / Black Rhinoceros (Diceros bicornis) two males fighting, Masai Mara National Reserve, Kenya

Yva Momatiuk & John Eastcott / Leopard (Panthera pardus) male threatens intruder with lips curled and canine teeth bared, Masai Mara National Reserve, Kenya

Gerry Ellis / Black Rhinoceros (Diceros bicornis) males battling, Masai Mara National Reserve, Kenya

Gerry Ellis / Black Rhinoceros (Diceros bicornis) males on savannah ready to battle, Masai Mara National Reserve, Kenya

Gerry Ellis / Black Rhinoceros (Diceros bicornis) males fighting, Masai Mara National Reserve, Kenya