On a wing and a prayer

Dave Sexton is RSPB Scotland's Mull Officer, working closely with the island's iconic white-tailed eagles. In this blog he discusses what is becoming a devastating year for the birds and those who work with them.

This usually my favourite time of year. Watching young sea eaglets successfully fledging and flying increasingly confidently, day by day, is what makes my heart soar. But this year is now turning into my worst nightmare.  

In the space of a week, I checked three nests where there was no sign of a chick. Just days before I’d watched fully grown, chocolate-brown chicks exercising their huge wings and getting ready for lift-off. It was clear something was very wrong. 

Dave had seen this chick alive a few days before there were signs something was wrong. Image credit: Steve Bentall.

It can be hard to see into sea eagle nests. They’re often high up in trees and with all the foliage and shadows it’s often difficult to know exactly what’s going on. But with patience, eventually, they usually give the game away and even watching from afar, I will see a wing stretch or hear a call.  

The first sign that something wasn’t right was at a nest where I had been getting increasingly worried about the chick. At first, I thought it had fledged because the parents were no longer returning to the nest with food.  

Sea eagle chicks usually spend a long time near their nest even after they’ve made their maiden flight. They perch in nearby trees or on hummocks along the shoreline and are not usually hard to locate. Even if I can’t see them, I can always hear them if I wait long enough! They carry on being fed by the adults for many weeks after fledging and they call a lot to let the parents know where they are.  

But at this nest there was no sign of the chick nearby and the parents didn’t appear to be collecting food to feed it at all.  

With a special licence from NatureScot to allow me to check closer, I’d found a vantage point which allowed a slightly better view. I thought I could make out a dark mass lying on the nest, but I couldn’t be sure. The branches and leaves were swaying in the breeze. There was no reaction from the parent birds. In fact, they’d just flown off as I approached. This was completely abnormal behaviour…and wouldn’t happen if the chick was still alive.  

As I got back to the pickup, my phone buzzed into life having been without signal for the last few hours. It was a text from BBC Springwatch’s Iolo Williams who was on Mull leading a wildlife tour. He often checked a nest in the south of the island which is visible from the road. I was hoping for one of his usual upbeat messages, maybe about having a curry in Tobermory, to boost my flagging morale but what I read plunged me deeper into despair. Blunt and to the point: “Hi Dave. Is the chick at Tiroran dead? It’s in the nest but hasn’t moved since yesterday…I think I can see a wing hanging over the edge”.  

I immediately set off for Glen Seilisdeir – the ‘glen of the irises’ – normally a favourite journey earlier in the season to see the yellow flag irises in full bloom and to check on the growing chick. I pulled up on the forestry track and set the telescope on the nest. I could immediately see the dark mass of brown feathers, but the body was motionless. The wind blew the beautiful primary and secondary feathers this way and that – so desperately close to flight. There was an occasional glimmer of hope when I thought it had moved, but I was fooling myself. A second nest with a suspected dead chick. What was happening? What was going wrong?

The Tiroran chick before it had fledged. Image credit: Steve Bentall.

As soon as possible, NatureScot arranged for two expert tree climbers to investigate. They were fitted with full PPE, face masks and ventilators, and climbed the huge Sitka spruces to take swabs from the dead chicks in two of the nests. At both nests the parents had long since given up and drifted away. They had returned several times with prey for the lifeless chick but eventually, with no reaction or food begging calls, their instinct told them their breeding season was over for this year.

Experts hired by NatureScot swabbed the dead chicks to test for Avian Influenza. Image credit: Rhian Evans.

A few days later, the results of the swabs came back. The one taken from the most recently deceased bird was positive for Highly Pathogenic Avian Influenza – HPAI – a new strain which has been killing our seabirds and geese in vast numbers since last winter. Now, it is killing our sea eagles. These birds are great scavengers and so they might have brought in sick or dead birds to feed the chicks, passing on this deadly disease.  

I don’t have all the results from all the Mull nests for which chicks have survived this year yet but so far at least four have either died in the nest or soon after fledging. This is on top of losses from bad weather and tree collapses earlier in the year.

The remains of a once-thriving chick. Image credit: Rhian Evans

Several other chicks in the west Highlands have died and have tested positive for HPAI. Although there was a dead adult sea eagle on Skye with HPAI last winter, so far, our mature birds, thankfully, seem to be surviving at least for now.  

My one ray of sunshine in a difficult week was finding my old friends’ Skye and Frisa’s 25th chick alive and well and she was flying confidently. I could have cried with relief. As they nest further in land, perhaps they’re bringing in less seabirds as prey for her? I can only hope, and pray, that continues and that she survives this devastating disease. Time will tell.

Skye and Frisa's 25th chick is thankfully still alive and well. Image credit: Steve Bentall.

Update: The chick was spotted in full flight on 30 August! Watch the clip on twitter or facebook.

The Scottish Government responded to calls for action on bird flu by setting up a task force led by NatureScot which will co-ordinate action to tackle the current outbreak, plan ahead for future outbreaks and take action to help protect and restore bird populations and improve their resilience. 

You can help by reporting dead seabirds, wild waterfowl (swans, geese or ducks), or birds of prey to the UK government Defra helpline (03459 33 55 77), and maintaining good hygiene when feeding garden birds. Please remain vigilant and do not handle sick or dead wild birds.  Learn more at: rspb.org.uk/birdflu

Header image credit: Katie Nethercoat.