British wildlife artist Robert E. Fuller rescues owls and tells their stories in his paintings and online. Luna is a tawny owl who was herself rescued in 2017. Her mate Bomber is quite a bit older and might not be fertile anymore. At any rate, Luna's eggs failed to hatch last year and this year. She seemed quite distraught. Then two extremely young owlets came into care, and Fuller took a chance and put them in Luna's nest.
Well, that escalated quickly. It took less than half a second for Luna to decide these were her chicks! Let's check in his the family a few days later.