Yellow-billed oxpeckers (Buphagus africanus) perched on the crest of an African or Cape buffalo (Syncerus caffer) and convening to decide on a strategy to remove parasites from their host. Oxpeckers are known to be beneficial to their hosts in what is known as a mutualistic, symbiotic relationship. Oxpeckers remove bloodsucking ecto-parasites and help control infestation of ticks. They also serve as an early warning system to their host by flying up and down, hissing and rasping, and causing the buffalo to look out for a potential threat.