A guest blog by Dave Sexton RSPB Scotland Mull Officer
It had all the hallmarks of an unfortunate accident: large sea eagle chick jumps up and down on nest, flapping wings, loses balance, misjudges landing and topples off nest to fall 30 feet to the ground below. After all, we had been here before. Sadly some eagle chicks do fall to their deaths when shuffling about on the nest or when they’re beginning to be more mobile and exercising their newly feathered wings. During the Mull Eagle Video Diaries for Autumnwatch 2008, I found Fingal and Iona’s nearly fledged chick, dead at the bottom of the nest tree. A devastating end to the breeding season for that pair of birds and all of us at the Mull Eagle Hide. On another occasion, a visitor had watched as another chick from the same nest fell out and had to be put down due to a spinal injury.
Just last year at Sula and Cuin’s nest one of their young chicks was found dead under the nest when we went in to ring the surviving sibling. There are so many potential problems these eagles have to overcome to survive. For Sula and Cuin’s chick last year, the fall was probably as a result of some strong winds and rain causing part of the nest to collapse and taking the poor chick with it. But this year was different…
The www.carnyx.tv webcam on Forestry Commission Scotland land on the isle of Mull has been operating now since early June. It’s a UK first for Mull Eagle Watch and it’s allowing viewers around the world a new window into the sometimes secret world of sea eagles at their nest. During Springwatch this year cameraman Jim Manthorpe filmed Sula and Cuin and family life at the eyrie. On the webcam, we’ve already seen both adults feeding the chick simultaneously which we’d never seen before. The chick didn’t know which adult beak full of food to grab at first! I think the term ‘pig out’ suitable describes it and by the end of that double feeding session, the chick’s crop was bulging to bursting point. She finally flopped down into the nest to sleep it all off.
On that fateful Sunday afternoon I logged on to check that all was well at the nest. I was immediately concerned by what I saw. Or rather didn’t see. There was no sign of the chick on the nest. I watched and waited. Could she have hopped round the back of the main trunk or ‘branched’ out on to a nearby limb? She was too big to lay flat and out of sight in the nest now. After 30 minutes of no movement I knew I had to go and inspect the site and raced towards the scene. On arrival, my worst fears were confirmed. The nest was definitely empty. It was too early for the chick to have fledged naturally. She was only 8 weeks old and needed another month’s development to be fully grown and able to fly.
As I weighed up the options I heard the distinctive cry of a young sea eagle. She was still alive, somewhere in the forest! Sula watched nervously from a nearby tree top as I went in closer to investigate. I’m licensed by Scottish Natural Heritage to do this - if the need arises. After a brief search I found the chick sitting on the ground and apparently unharmed. I gave her a quick check over: legs ok; wings ok; alert. With no foxes on Mull I decided to make her comfortable and to leave her where she was until I could get help to return her to the nest. Sula and Cuin knew where she was and may well have fed her on the ground.
The following morning I was joined by expert tree climbers from Forestry Commission Scotland, John Taylor and Philippa Revill, and together we located her again (she’d wandered off further into the trees) and then got her safely back where she belonged. John checked the nest. All was sturdy and secure so nothing had given way causing her to fall. One local observer had seen her exercising her wings a lot the day before and thought she’d looked “unsteady”. That was it! There was our explanation as we’d suspected all along. Some over-zealous trampolining had caused the accident. She was lucky to have survived the fall with no injuries and even luckier now to be back home with a big slab of Mull salmon and a couple of rabbits to tide her over until Sula and Cuin resumed feeding her. Job done. I thanked John and Philippa and returned them to the ferry.
Then came the first mention from someone watching the webcam the previous day of an “intruding eagle”… Toby Dobson at Carnyx Wild trawled through hours of footage until he stumbled upon the unbelievable proof of what had really happened that warm June evening. At first for me it was shocking to learn the truth; the news was hard to take in and even harder to watch.
A one year old immature sea eagle had invaded the nest presumably looking for a free meal of prey leftovers. This bit wasn’t so surprising. We’ve seen immature eagles loiter around active nests before. They’re quite inquisitive and can make a real nuisance of themselves. But this bird was not just a hungry, curious youngster. She was a feisty, bullying female who would not tolerate any competition. After some fierce scuffles she succeeded in forcing the terrified chick further and further back until, with one final lunge, she pushed her off the nest to her unknown fate. The intruder clearly couldn’t care less. With one brief look over the rim of the nest to ensure the problem chick had been well and truly dealt with, it was mission accomplished. She turned back into the nest and proceeded to scavenge her way through the remnants of prey. She was like some monstrous great sea eagle/cuckoo hybrid who wouldn’t be satisfied until she’d turfed out the original contents of the nest.
There was more drama to come as Cuin arrived back at the nest with fresh food. Assuming for a brief moment it was his chick on the nest, he was suddenly set upon by the stroppy young eagle which had invaded their home. Despite his best efforts, Cuin could not dislodge the intruder and it wasn’t until Sula also appeared back at the nest that the visitor finally decided she’d outstayed her welcome and rapidly fled the crime scene. Remarkable, raw, dramatic footage and behaviour never before recorded. Was the intruder Sula and Cuin’s single chick from 2013? She has a ring on but we can’t read it from the footage. It would make sense as she’d be familiar with the nest area and would know to expect food there.
But it was hardly the warmest of ways to welcome your new baby sister to the world…survival of the fittest!
Watch the drama unfold here:
part 1 http://vimeo.com/99680219
part 2 http://vimeo.com/99689971
part 3 http://vimeo.com/99690607
Since all the drama unfolded the chick has now sucessfully fledged. A happy ending.....or rather begining!
Mull Eagle watch is a partnership between Forestry Commission Scotland, Scottish Natural Heritage, Mull and Iona Community Trust, Police Scotland and RSPB. Trips to the Mull Eagle Hide run daily Monday to Friday 10am and 1pm. Call 01680 812 556 for information.
Dave Sexton RSPB Scotland Mull Officer