Lions prefer to scavenge when the opportunity presents itself[82] with carrion providing more than 50% of their diet. They scavenge animals either dead from natural causes (disease) or killed by other predators, and keep a constant lookout for circling vultures, being keenly aware that they indicate an animal dead or in distress.[82] In fact, most dead prey on which both hyenas and lions feed upon are killed by the hyenas instead of the lions.