As someone who just finished writing an essay on the red-billed oxpecker (and the pearlfish as well), I thought I would share some information.
Did you know that the red-billed oxpecker feeds not only on the ticks of the large mammals it thrives on, but also stuff like earwax, skin, and blood? And that they can open new wounds on these animals in order to drink the blood, kind of like a vampire bat?
So much so that the previously assumed mutualism of these species is under question, and it has been wondered if the oxpecker is in fact more of a parasite.
If you don’t believe me, there’s also the vampire finch which has a similar strategy. Whatttt.