Are they the owl couple who have been seen inside the kastle? That seems to be the elephant in the room. We know that this couple seem to be familiar with the box and the sounds of the camera moving. They maneuver the playground and surrounding area like this is home. The couple are also familiar with each other, unlike how a new pair would react upon forming a new bond.
So if Mel didn't meet his demise as some have speculated and left Sydney to raise and feed Adi & Hunter where she was unable to keep up and abandoned our babies and the nest, and move on to further territories, what is the answer?? Well.. there is no answer on why nature does what it does. Looking up page after page searching for the answer on Google, the research just isn't there to best answer that question.
From the Hungry Owl Project they too have had a similar issue with one of their boxes. Joe from the project checked with some of the foster and rescue crew about our situation. Come to find out it sounds like they have had a very similar situation with the parents at a nest feeding less and less and the project had to supplement. "Also the first time we've observed something like this." In their region of Northern Ca, they claim its been a really really weird year. Many owls who are normally very reliable nesters, nesting in the same boxes for many years, with multiple clutches a year are just not nesting this year. They've also had many reports of really small clutches, just a couple eggs vs the usual 6 or 7.
I don't think we will are know the reason why we had such a difficult clutch this year, we just have to respect it and perhaps learn from it, that things happen in nature that we as humans don't understand or have answers for. What we do know is that for sure our babies Adi and Hunter would have perished from lack of food and active parents to guide them and if it wasn't for kanga supplying the food and exercising a plan for training to teach them to hunt, they're would be two less owls in the free flying world.