red-billed oxpecker african bird pulling fur of impala to make nest at serengeti in tanzania, africa

africa african antelope beneficial benefit between billed bird buphagidae cattle different east feeding fur hair hitch impala infested insect interaction livestock living mammal material national native nest nesting oxpecker parasite park passerine pecking perch perching pick plucked plucking pull pulling red relationship savannah serengeti skin symbiotic tanzania tick tickbird