This exerpt from a National Geographic TV program shows a seemingly unique sequence of events where a hippopotamus, after witnessing a crocodile attack a baby antelope chases the croc away and proceeds to gently nudge the antelope ashore and perform what appears to be some sort of life rescue/support attempts.
I’m aware that this can very quickly degenerate into GD about anthropomorphizing wild animals, so my question is simple and to the point: What is a good scholarly starting point in researching such hippo behavior, if any? Specifically I am interested in a) chasing away a crocodile b) protecting an antelope or any other weaker animal, including young hippos c) the act of putting a head in its mouth so gently.
A cursory look through my university library catalog did not yield any books on the hippopotamus that were not photography or children’s literature. I lost my priviliges to search the electronic article databases after I graduated, and a scan through google scholar reveals slim pickings. A few things about hippo mating, some about the symbiotic relationship with Jacanas, and the rest about taxonomy and, for some reason, chimpanzees. However, my background in zoology and natural science in general is almost non-existant so perhaps I am using incorrect terms for my search?
I realize that hippo is an extremely dangerous animal and its territorial nature makes it difficult to study, but surely this behavior has been documented somewhere other than an edited 2 minute national geographic clip. The specific act of defending an antelope and putting a head in its mouth might have been relatively unique, but defending its own offspring and caring for the wounded young cannot be all that rare.