Another successful year for the Loch Insh ospreys

Pete Moore, Warden at RSPB Insh Marshes shares with us the story of the ospreys at Loch Insh, inspired by another successful fledging this year!

Another successful year for the Loch Insh ospreys

July 2020 saw three sibling ospreys fly from their nest atop a large larch tree on a wooded island in Loch Insh, part of RSPB’s Insh Marshes reserve. I am always delighted to see young ospreys fledge but especially so this year, which I hear has been a bad one for many pairs of ospreys.

The total number of young raised successfully from the Loch Insh nest now stands at fifty-three, spread over the twenty-eight years since the nest was first built in 1993. Of course, it hasn’t been the same breeding pair all that time, with five different males and four different females taking their turn at making the nest their own. How do we know? Because many Scottish ospreys are ringed as chicks and wear coloured leg rings to enable individual identification. 

The current female, whose coloured leg ring tells us that she was born in Argyll, has just completed her thirteenth year at this nest and has only failed to produce young on one occasion. That was in 2012 when the weather was so awful that she was forced to abandon the nest after days of heavy rain. What a fantastic track record she has – thirty-two young raised in total! I so hope that she will return next year. 

Although remarkably successful overall, even the Loch Insh nest has had its moments! Indeed, it got off to a rocky start with no young raised in the first three years, 1993 to 1995. The eggs were stolen in 1995, after which rings of metal spikes were attached to the stem of the nest tree to deter would-be thieves.  

Ospreys add more sticks to the nest every year so the nest gets bigger and bigger and can eventually become top heavy. This is probably why the nest blew out of the tree one winter! We wanted to rebuild the nest but the same metal spikes that were there to deter egg thieves presented a significant challenge to tree-climbing RSPB staff who had more honourable intentions. It took three hours to get past the defences and a further hour to tie some sticks into the top of the tree and create a base for the ospreys to build on. The ospreys arrived in spring and took readily to their new nest, none the wiser as to the exertions of RSPB staff on their behalf!

The male of a pair does all the fishing during the nesting period, supplying the female and any young with the fish that they need. It was therefore potentially disastrous when in 2011 the Loch Insh male became entangled in a pike fisherman’s unattended line. By the time the fisherman realised what was happening, the bird was waterlogged, dishevelled and worryingly had lost some flight feathers. The fisherman took it into his tent and when it was drier and warmer, he released it. Luckily, the bird was fit enough to return to duties, a close escape indeed! 

A colleague once remarked that the Loch Insh nest was one of the most important in Scotland because the young are raised in close proximity to large numbers of birdwatchers, photographers and canoeists. He theorised that when the young birds returned to Scotland to breed, they would be happy to nest near to people and not be overly sensitive to disturbance. I don’t know how true that is, but for purely personal reasons, I am happy to agree that it is one of the most important osprey nests in Scotland!