Bonding between different species of animals is not an exception at all. I have seen it happening between our pets.
Our Preiti took a while but once she knew she was safe she befriended Gamma our rooster and the neighbour’s cat.
Gamma and Preiti were the best of friends. They went on a stroll together, chased each other and as you can see in the photo exchanged perhaps some thoughts in their own way.
Preiti had a great time with the neighbour’s cat as well. She visited us just to play with Preiti.
Even when Charlie the baby monkey visited us she would wag her tail looking at it although we did not encourage proximity.
There are stories where kittens are seen being breast fed by a dog.
Do you have different species of pets that get along with each other?