Disney World: Osprey Intervention and Ringing

Following discussions at meetings of the Welsh Osprey Forum over the 2016/7 winter, this is a combined statement issued by Bywyd Gwyllt Glaslyn Wildlife and Montgomeryshire Wildlife Trust pertaining to the Glaslyn and Dyfi osprey nests.


Once upon a time, in a country not very far away, stood an osprey nest. Every year the same parent birds returned to their nest and successfully raised two or three chicks - there were no problems, disease, injuries, accidents and no incidents of any kind. Just a nest-full of beautiful and healthy chicks each and every year, many destined to return from Africa years later as adults and breed for themselves.

 The Glaslyn male, Ochre 11(98), returns for yet another successful breeding year in 2005

Of course we know that this situation rarely exists in the real world - so how come it did at the Glaslyn nest for the best part of a decade?

The UK figure for annual osprey nest productivity - the number of chicks that fledge per nest per year - is low and will probably surprise you. It's a fraction over one chick per nest. Yet for the first 10 years at the Glaslyn we had a veritable bounty of chicks - two, or more usually three, every year, completely defying the national average by huge amounts, 200% and 300%.

Moreover, the combined national Welsh average between all four nests is still over two chicks per nest today - double the UK average. So what's going on?

 The bounty years - Glaslyn chick productivity for the first 10 years


There are two main reasons for this seemingly improbable success - basic ecological population dynamics and luck.


Ospreys are gregarious birds, unusual for birds of prey. They are what we call 'semi-colonial', they like being around other ospreys.

In a normalised population, ospreys nest in loose colonies of between several to many hundreds of nests in an ecological state of homeostasis. This state of osprey population equilibrium is governed by a principle we call "density dependency"; a fancy way of saying that population growth rates are regulated by the number of individuals in a population. Density dependency is a well known ecological process that governs the population ecology of practically all living organisms from bacteria, parasites, plants and animals.

For many years the combined total number of breeding nests in the Welsh population was one. Then it was two. This is not a 'normalised' population, it is what we call a recovering population and very much an un-natural state of affairs, completely devoid of the usual restrictions placed on populations by the mostly negative effects of density dependency such as crowding, increased predation and competition for food, mates, nest sites and other resources.

The combined breeding osprey population in Wales throughout the 2000s - two birds

The inevitable consequences (thankfully) for populations that are lacking these negative effects of density dependency are increased productivity. This is exactly what we saw, and really expected, at the Glaslyn nest for all those years.


We have all heard of 'survival of the fittest'. It was actually English philosopher Herbert Spencer, and not Darwin, who first coined the phrase 'survival of the fittest' and it is a phrase that is not normally used by evolutionary biologists today for several reasons. Basically, and despite having that catchphrase quality we all like, it fails to describe satisfactorily many of the principles involved in natural selection.

Yes, evolution favours the fittest, but also the luckiest. Natural selection has zero regard for that next chick-murdering storm brewing over the Atlantic, nor for that Douglas fir branch that's so rotten it will give way the next time a wren lands on it, let alone an 2kg osprey. How about the unluckiest pine marten that was just about to munch through three unguarded osprey eggs before being hauled off the nest just seconds before its nutritious egg feast by a predatory buzzard?

Everything alive today is the product of an almost impossible chain reaction of statistically improbable events. If you thought your chances of winning the lottery were remote (around 13 million to one in the UK), you, and all of your ancestors going back the best part of four billion years, are some of the luckiest collection of molecules around in the whole universe. You have beaten the Lottery odds several times over.

The very fact that you are reading this right now means that there are billions of your ancestors that aren't. They were tossed aside in the evolutionary lottery game of chance and luck, never destined to make it as far as the present day. You are, as Richard Dawkins once wrote, cast members of The Greatest Show on Earth.

So what has luck got to do with any of the Welsh ospreys?

What odds that a 1998 Scottish born osprey would be translocated to Rutland Water at five weeks old, survive the next six years and make it back to North Wales. of all places, and build a nest, well over 100 miles away from the next nearest osprey nest? What odds that he would find a female in a country that has so few ospreys, the last recorded breeding was documented over 400 years ago?

 Ochre 11(98) - Good genes or good luck?                                                                                 © Leicestershire & Rutland Wildlife Trust


What odds that after their first naturally built nest collapsed in a July storm in 2004, it would be rebuilt later that year by another species - the very one that originally persecuted the osprey to extinction in the UK, to such a robust construction design, it was practically guaranteed never to collapse, no matter what the Snowdonia weather could throw at it?

What odds that the male would return the following year? What odds the female would return the following year? What odds the male would live another 10 years and return to breed at the same nest? What odds the female would too? What odds that this pair would successfully breed each year, completely devoid of any density dependency restrictions of crowding, interference and competition for mates?

You get my drift. The probability of all these things happening were astronomical, yet, they did. Yes, both 'Orange 11' and 'Mrs. G' were amongst the fittest of their kind, they were also some of the most fortunate. That's luck.

The Year the Luck Ran Out

So we get to 2016 and all sorts of 'strange things' start to happen.

Dai Dot is displaced at his Mid Wales nest by another male and is photographed a few weeks later at Cors Dyfi with a possible injury to his right wing. A Dyfi egg ends up not hatching. The exact same happens at the Glaslyn. It's hardly ever happened before.

 The last time Dai Dot was sighted, possibly injured - April 2016

One of the Glaslyn chicks sustains what looks like a serious leg injury at six weeks old. Then its sibling acquires an injury after landing awkwardly shortly after fledging. One of the Dyfi chicks also sustains an injury after falling off a perch at midnight, just three days after fledgling. The two Glaslyn chicks, against all the odds (so here comes the luck part again), survive. The Dyfi chick, Ceri, doesn't.

These are not 'strange things' at all.

Your chances of flipping a coin five times and getting Heads every time are 32 to 1. The chances of the England cricket captain winning the toss all five times in a five-test cricket series are the same, 32 to 1. There's nothing mysterious happening here, there's no conspiracy or supernatural things happening, he - or she - has been lucky. It will happen again and again and again, on average, after every 32 test match series.

As well as being unlucky, Dai Dot, W7, W8 and Ceri were the victims of the other force in play here - the density dependency stuff.

 The Glaslyn chicks W7 and W8 shortly after fledging in 2016 - a perilous time for young ospreys

Thankfully Wales is becoming more populated with ospreys. Four breeding pairs and many more birds over-summering here. It is far from being a natural population yet, but it is, hopefully, on the long road to being so.

Other birds are a nuisance to breeding pairs - just ask Dai Dot. They introduce crowding and more competition for mates and nests. Blue 24 has been a perpetual thorn in Glesni's side at the Dyfi and now we have another Rutland female - Blue 5F, doing the same at Glaslyn. It is impossible to prove in just one year, but these birds were almost certainly the causal influence resulting in two unhatched eggs at both nests.

Bird Ringing

We take osprey identification for granted: Glesni, EJ, the original Glaslyn male, Orange 11. Five of the Glaslyn offspring ( Yellow 37, White YA, Black 80, White YC and White 91) have returned to the UK and have successfully bred for themselves, raising over 50 chicks of their own to date. Another Glaslyn bird has also been re-spotted having returned - a 2012 male, Blue 80. Clarach (Blue 2R b.2013) from the Dyfi has also made it back as an adult as has Blue 9R, a 2014 chick from the second Snowdonia nest. We know all of this for one reason only - all these birds were ringed as chicks.

 Glaslyn's White YC (b. 2008) breeding at a Wildlife Trust nest in Cumbria

Bird ringing is the most effective, elegant and non-destructive research tool ever invented to learn more about the ecology and movements of birds. It has stood the test of time - over a century now, and is still the best tool we have to gain knowledge of bird populations; knowledge that we use to help in their conservation, and boy, do some species need conserving after the persecution and habitat loss/changes they've suffered.

Ringing is a strictly regulated process, with permits issued by the British Trust for Ornithology (BTO) on behalf of the Country Agencies. All participants in the Ringing Scheme undergo a prolonged period of training during which they are individually mentored by a qualified Trainer who monitors their progress and dictates what activities they are permitted to participate in.

BTO staff grant permission to fit colour rings to songbirds and raptors on a project by project basis, taking account of the welfare of the birds and the value of the data likely to be produced; a similar process is undertaken for fitting of tags and devices, overseen by an independent panel of experts.

Ringers are tree climbers, cliff hangers, cave clingers and rope and ladder hugging professionals working in inaccessible and tough environments most of us skip a heart beat just thinking about. They are amongst the most respected fieldworkers in the bird world, and most do it for no pay, purely on a voluntary basis.

 Celyn, Blue W2, is ready to go back in the Dyfi nest after being ringed


Yet, in 2016, some of these bird ringers in Wales faced a situation that they had never really encountered before - a torrent of critical, vitriolic and abusive comments, mostly on social media. So severe was some of the abuse, one of our ringers has decided not to ring ospreys again, after over 10 consecutive years of doing so.

The nature of the comments were mono-themed: The cause of all these 'mysterious' things going wrong was somehow caused by the ringers. This is simply not true. If a mistake had been made, we'd tell you.


Social Media

When ospreys first started breeding in England and Wales again at the start of this century, there was no such thing as social media. No smart phones, tablets, no Facebook, Twitter, Youtube and all the rest of them. All these platforms have, however, helped the osprey enormously as a species to recover and flourish during the last decade.

We can tell their stories, their ecologies, show pictures and videos. In 2012 for the first time in Wales, we were able to stream live pictures from an osprey nest at Dyfi. I once saw a passenger on the London underground watching the Dyfi ospreys live on their phone on their way to work - I had a sneaky peak. Unreal. Three of the four ospreys nests in Wales receive little or no funding at all, we have to raise all the funds needed ourselves, mainly via the kind support from followers like yourselves. Social media has played a huge part in allowing us to do this and has helped immeasurably in the conservation of ospreys.

 Thousands of people engage with ospreys on social media

For all the good it can bring to bear, however, social media can also be a hindrance. We saw this manifest itself in 2016 with all these abusive comments. It's very easy to hide behind a computer screen, phone or tablet and write whatever you like; I'm sure many of these things would never have been said in a face-to-face conversation.

Disney World

All of us involved working full time with wildlife make decisions daily based on our qualifications, experiences and knowledge. We do not have "Intervention Policies". Decisions are made during times of adversity based solely on one criterion only, what is the best course of action, right now, for that osprey and its family members.

At the first sign of a limp or a cough, we can't simply scramble people together and climb a 100 foot tree or ladder up to a 40 foot platform. These actions have consequences on all sorts of other things such as the other birds concerned, legally, and the safety of the people involved.

Many of you may remember the time we managed to take Ceulan down from his nest in 2012 after both his siblings had died of malnutrition and exposure beside him, or the Cerist search in 2013 when she went missing for over two days whilst fledging. Both decisions worked out, but they were meticulously thought through and the cost:benefit analysis vigorously explored. There was no guarantee of success and things could easily have turned out very differently.

 Looking for Cerist by the Dyfi River in 2013

As for the injured chicks in the Dyfi and Glaslyn nests in 2016, we could not intervene as this would have deleteriously affected the other birds in the nest. There was no other way. This isn’t Disney World - we can't magic these birds and teleport them to some 'rehab centre' somewhere and hope everything will be alright.

What We Ask of You

The vast majority of you guys are completely understanding of the nature of our work and the decisions we sometimes have to make when things go wrong. In fact, I have seen so many of our supporters defend our actions to concerned members of the public.

We absolutely welcome questions, constructive criticism, and enquiries as to the reasons why we take the decisions we do. Scrutiny is a good thing - just imagine if there were none in the environmental sector? Our wildlife would be much the poorer without scrutiny.

As you know, we go out of our way to be completely honest and transparent, explaining the reasoning and thinking behind some of the difficult decisions we take under adversity. We don't have to and many organisations don't. Politely ask any questions by all means, but please think about the fact that there are real people at the other end. If you care so passionately about the ospreys in question - imagine how passionately the people this end do?

Abuse has no place in civil society. Last year we had threats, some of them very personal, and some of the worst and vitriolic abuse I've seen since working with ospreys. It is heartbreaking that a ringer with decades of experience and one of the most caring and compassionate people I know, decides to throw in the towel after being so upset by a tiny minority.

The next time we have an injured chick or an osprey in distress somewhere, the last thing we want to do is to worry about what people, sometimes thousands of miles away, may think of our decisions. That should not have to enter our decision making process. If it did, it would be the ospreys that would ultimately end up the poorer.

Thank you for your understanding and reading this far. We absolutely guarantee you we'll do our very best for the ospreys, but we can't guarantee a 'happy ever after' outcome. These are wild birds, it's nature, it's unpredictable and it certainly isn't Disney World. That's all folks.

Emyr Evans