Marlyss Simmons shared a video with me which raises a question of what is "natural". Certainly, we as humans have long ago left our state of "nature", sometime between when we picked up a rock as a tool and when we learned to plant crops and live communally around 9000 years ago. Somewhere before that time, humans and canines were competing for the same food sources and became slowly codependent. The story of canine development was outlined in this past Natural History magazine article.
The more we associate with wildlife, the more their behavior toward us is modified. My neighbor in Ravenwood chases "wild" deer out of her back yard garden, only to have them follow her back down the block. Squirrels become emboldened after daily association with humans.
An even more interesting relationship is seen at times between various animal species which hang around us gregarious humans. Marlyss sent this video which shows the spontaneous relationship between an orangutan and a stray hound dog. The internet provides lots of examples including Noah the dove, a foster mother to baby bunnies. Almost all of these stories have in common one thing- one or both animals having a longtime association with humans in a nurturing relationship.