They are most often observed singly or in pairs as opposed to the colonial behavior of other cathartids. King vultures are diurnal carnivorous scavengers. Numerous individuals kept in exposed conditions have been reported to have suffered frostbitten toes and feet, with some subsequently losing extremities or requiring euthanasia. King vultures are long-lived, have low fecundity, and have comparatively simple husbandry needs. Although typical seasonal production would consist of a single egg, some pairs have produced up to three chicks in a season when the hatchlings are lost or taken relatively early.
King vultures are sensitive when nesting and have a tendency to kill hatchlings.
Hand-raised individuals are accordingly not uncommon. King vultures typically tend to be very aggressive when defending their nest site. Hand-raised birds, with little fear of humans, may pose even more danger. Young king vultures have been known to chase down and kill mourning doves that squeezed through the wire of their enclosure. Most often, the doves were not consumed.