h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

Someone in my neighborhood told me of a mother hen who found herself with ducklings. She promptly led them to where they could find duckling food. I believe that dog puppies can join wolf packs under the right circumstances. St least Jack London wrote a story in which that happened.

On the dark side: Cuckoos and grackles that lay their eggs in the nests of other bird species, knowing that the other birds will raise them as their own.

I often think that the cuckoo chick's 'foster' parents do realize that they're cuckoos but are simply too fond of the little things to just let them die of hunger...

Bids are thought to have evolved from dinosaurs.

There's a place in Montana where a fossil dinosaur mother was apparently spreading her arms or wings or whatever to protect her babies from volcanic ash, etc. The mothering instinct was present in dinosaurs, which seems to distinguish dinosaurs from reptiles. There may be reptiles with mothering instincts (just as there are frogs who can care for their young), but it's not the norm.