When I wrote that yellow-headed caracaras pick ticks off of mammals Dr. Tony Bledsoe pointed out that, based on the similar behavior of an African bird, it’s possible the caracaras are also drinking the animals’ blood.
Ewww! What gives?
In Africa, there are birds called oxpeckers (two species in genus Buphagus: yellow-billed and red-billed) that also perch on mammals and eat ticks, lice, fleas, and biting flies found on the animals’ skin. Studies have shown that individual oxpeckers eat up to 100 engorged ticks or 13,000 nymphs per day. Quite a benefit to the animal!
Engorged ticks contain tiny blood meals so it’s not a big leap that the oxpeckers sometimes to go directly to the blood source, pecking and plucking at an animal’s wounds. Despite this parasitic and perhaps painful behavior, many mammals tolerate the oxpeckers although elephants and some antelopes shoo them off when they land.
Yellow-headed caracaras are unrelated to oxpeckers but their tick-eating behavior extends to blood meals as well. The Handbook of the Birds of the World includes this remark about the caracara’s eating habits:
“Perches on cattle and Capybaras (Hydrochoerus hydrochaeris) to pick off ticks; picks flesh from open wounds on backs of cattle, which often seem oddly indifferent to the process.”
It sounds gruesome but the benefits of having your own portable tick-remover apparently outweigh the occasional blood meal.
(photos from Wikimedia Commons. Click on the images to see the original)