This wasn't the blog I'd planned to write tonight but I thought readers might like to hear of an adventure at Loch Frisa today. The other blog will have to wait a while.

Today dawned bright and very frosty. There was ice on the road and the grass crunched under foot. The sheep were huddled round a bale of fresh, sweet hay munching eagerly after a long, chilly night. Loch Frisa looked idyllic: not a ripple on the surface apart form the occasional trout; in one bay a dabchick was busy diving every few minutes and a cormorant was perched out on the island in front of the Eagle Hide. Frisa was sitting on her favourite grassy knoll and Skye was in the larches staring down into his usual burn. Little by little the winter sun edged higher, first illuminating Frisa and then Skye, both looking regal and magnificent in the early morning sunshine.

Out of the blue flapped a sub-adult sea eagle, crossing the glen, over the hide and up into some spruce trees above the loch. I spilled half my coffee as I scrambled to get the telescope in position. The steam of the coffee billowed up in the sub-zero air, fogged up the eye-piece and obscured my view. As it cleared, I got the 'scope in focus and there was the eagle, looking unsettled, but with wing tags which were easy to read. They were yellow, that meant 2006. And the letter was 'H'. That could only mean one thing; I was looking at good old Haggis, one of Frisa and Skye's twins from that year. He was now heading towards being four years old and he looked every bit the young adult. His beak was already yellow and his head pale but his tail was far from being pure white and I could see his eye colour was still that of a youngster. He had flown over Frisa and virtually passed Skye and he was looking distinctly uneasy. This was not to be the warm homecoming he might have hoped for. Within a few minutes, the welcome from Skye matched the air temperature and things turned distinctly frosty. He flew round and perched on a boulder just 50m from Haggis. This seriously spooked the young male and he took off - with Skye in hot pursuit. They skirted round the front edge of the larches and vanished into the forest. Over the next 10 minutes, first one, then the other would shoot out of the trees before I'd lose sight of them again as they raced back into a fire break. Then I noticed Frisa had gone from her hummock and there she was steaming across to join the fracas. She too crashed into the forest and there was silence. To be honest, there were times when I feared for Haggis. I could only imagine what was going on in there. As far as Frisa and Skye were concerned, especially Skye, here was a young pretender, a sub-adult male in the heart of his nesting territory. There could be no bigger threat to him. Would they know it was their Haggis just stopping by to see the folks? Sorry. Probably not.

Haggis and his brother Oatie were named by children at Lochdonhead Primary School in 2006 They were the stars of their day; they starred on our webcam that year and Kate Humble came north to film them for the pilot series of The One Show. Later we received reports of them from various parts of Mull, then Haggis turned up in the Outer Hebrides on Lewis. Later he was reunited with Oatie at Loch Scridain on Mull and was recorded last year over on the east coast. So he has been quite a traveller in his young life. The least he might have received was a warm welcome when he drifted homewards. But it was not to be. This is, after all, the wild, not Disneyworld.

Every now and then I could hear calling from withing the forest, distant echoing calls. Then without warning first Frisa, then Skye flew up and perched together in a big Sitka. But no Haggis. The pair called loudly on and off for the next half hour and sat side by side, united. I can only guess and hope that Haggis made his escape thought the back of the forest and out across the brown wintry hills out of sight from me. His life journey was not over yet. Or perhaps he was hiding in the dense plantation, waiting for his moment to break free when his angry parents were not watching. Some hope. For now, at least peace was restored to their loch-side home . It had been a rare insight into the private life and times of our famous Mull white-tailed eagles. It may not have been the fairytale reunion we'd have liked for the returning long-lost son but these are wild spirits and we wouldn't actually have them any other way.

I'm off south for a few days into the Smoke for my own family reunion. I hope I get a warmer welcome!

Dave Sexton RSPB Scotland Mull Officer

Don't miss The Natural World this Thursday 3 December BBC Two 9pm: HIGHLAND HAVEN. It's a winner.   Here is a short preview clip http://www.youtube.com/watch?v=SlPqpzEnYv4