We had already postponed the fitting of the satellite tags to the two sea eagle chicks at Loch Frisa at least twice. The weather just wasn't good enough. We needed dry, settled conditions. You wouldn't think that was too much to ask in June but the perfect day remained elusive. Not only that, but I was also trying to coordinate the date with our expert tree climber Justin Grant, our world renowned bird of prey specialist who would fit the tags, Roy Dennis - oh yes and the internationally acclaimed (well, quite famous on Mull) cameraman and presenter Gordon Buchanan and crew! Our window of opportunity was small. Justin had many other nests and trees to visit in Scotland, Roy was due to leave for Japan shortly and Gordon was due in Papua New Guinea for his next expedition very soon. And the chicks were getting bigger and less easy to handle by the day. Finally, it all came together: the weather, everyone's availability and the chicks were the right age. Tagging day had arrived. The night before such an event, you just don't sleep very well. By the time the alarm eventually goes off, you've been lying there waiting for it, running over things in your mind, planning every last task and preparing for any eventuality. In short, you feel awful before the day has even begun! I collected Roy from the Lochaline-Fishnish ferry and we all met up at the hide. The crew were ready, Justin was carrying out some last minute checks on his climbing gear and Frisa and Skye were perched, relaxed and preening in their usual conifer. Little did they know what was about to invade their world. Some early drizzle had eased and the sun was appearing. Unfortunately that moisture would make the tree slippery and dangerous for Justin. When you're grappling with two month old, almost fully grown young eagles 40 feet up a tree, you do not need any extra hazards.

I truly hate that moment when Frisa and Skye suddenly realise that you're not just a group of walkers passing through, but that you're heading straight for the nest. They launched off from their tree in panic and began circling low overhead and calling in alarm as we got nearer and nearer. Unlike golden eagles which remain distant or out of sight, sea eagles make themselves very obvious and can sometimes come worryingly close (sadly it's what made them so easy to shoot back in Victorian days when egg collectors or others who would do them harm, approached their nests). No matter how many years I do this job, I dislike that phase of the work more than I can say. And yet, I know that for the good of the project overall, it's a job that must be done. The stress levels are at bursting point. I want it to be over. I want the job done and I want Frisa and Skye and the chicks to relax and get back to normal. I just want to get out of there and if a TV crew dare to say 'can we just do that again?' I think the look on my face probably provides them with the answer. That's why working with Gordon, Richard and the Autumnwatch crew is just perfect. They know what they want, they work around us all doing what we have to do and they never ask 'can we just do that again?' (except when Gordon has to re-do his make-up).

Finally, 40 feet up, Justin reached the nest, he had one chick in a bag ready to be lowered and he was gently calming the other which was trying to take a chunk of flesh out of his hand. Below we waited for that signal that Justin was ready to lower the bag with the precious cargo. The ropes were tightened. Gordon took up the slack. "Ready!" Justin eased the bag over the edge of the nest and into the forest canopy. As I start to pull the bag towards me, I'm praying silently (sometimes not so silently) that the ropes hold, the knots hold, the bag holds and that the chick survives the descent. It's a nightmare moment. Here goes...

Dave Sexton RSPB Scotland Mull Officer

Autumnwatch is back for Week 2. The Mull Eagle Diary films are now scheduled to begin Tuesday 4 November BBC Two 8pm.