Dik-dik , Impala , Waterbuck , Grevy's Zebra , and Beisa Oryx . There are over 350 species of birds. These include Somali Ostrich , Kingfisher , Sunbird , Bee-eater , Marabou Stork , Tawny Eagle , Bateleur , Guinea fowl and Vultures . The Uaso Nyiro River contains large numbers