In this video, filmed at Budapest Zoo, a bear pauses his meal to rescue a crow that's drowning in his enclosure.
Some online commentators have speculated the brown bear, Vali, was planning to eat the crow, but changed her mind. However, it certainly doesn't look like that to us, and indeed the crow makes no effort to get away. Whether Vali's motivation was simple compassion, curiosity or a desire to have something to play with isn't clear. While curiosity or playfulness fit fairly well into models of animal behavior, the idea of helping another species out through a desire to prevent suffering is one that meets plenty of resistance.
Budapest Zoo has a discussion of the clip, but unfortunately the translation function doesn't work too well. Anyone with a better (ie some) knowledge of Hungarian is welcome to fill us in.
Update: Reader Imre Jánoki has kindly summarised the zoo's website for us. They back the curiosity theory. They add that hooded crows such as this one have been taking over the zoo, stealing meat from the lions and tigers and requiring zoo staff to protect small animals such as guinea pigs. Finally the site notes, "the crow was lucky to meet Vali instead of the other tenant of the paddock named Defoe, as the latter probably would have had a taste of the black bird."