Posted: Saturday 9th January 2021 by Emyr MWT

Great News: The 2020 DNA results are in.



As you know, we attempt a best guess at what sex our chicks are each year when we ring them under the nest at around five weeks old. The older the bird is, generally, the better your gender accuracy potential.

Both Teifi and Tywi were slightly under five weeks old at ringing in 2020


Guessing a chick's gender is not a perfect science. It's based on the weight of the chick, the 'feel', the thickness of the tarsi (leg bones), wing length, plus the behaviours we've observed hitherto. Our ringer, Tony Cross, probably has a 90% input with the other 10% coming from the DOP team to arrive at a gender for each bird.

What is an exact science, however, is DNA testing.

So, without further ado, we can confirm that after analysing the saliva swabs for genetic sex markers, Tywi and Teifi are indeed two boys as we had predicted.

Both Tywi and Teifi's weight fell neatly in the male range compared to previous Dyfi chicks
Wing lengths are a less accurate indicator of gender, but an useful tool nonetheless


Proof of male sex: Click here for Dr. Helen's explanation


Experience and Accuracy

Huge credit again goes to Tony who maintains a 100% accuracy in predicting the gender of all our chicks at just five weeks old. To date, we've only had one "?" we attributed to a bird at the time of ringing as we just didn't know; that was Merin back in 2015 who we now know is a male based on the subsequent DNA analysis plus breeding behaviours observed in Denmark as an adult.

A phenomenal record - well done Tony. There's 40 years' experience for you.

Teifi's way of thanking Tony in July 2020 for taking his buccal swab

Other Welsh Nests

All the Clywedog chicks were accurately assessed for gender too - they were indeed three boys. The Llyn Brenig chick was also correct - a female named Dwynwen.

Three healthy boys at Llyn Clywedog, 12 miles south of the Dyfi.       ©NRW

Things were a bit different at Glaslyn this year as they chose not to weigh their chicks due to the excessive heat in order to save time (the Glaslyn nest is 25m high up in a silver fir tree). See their blog here.

What About Idris?

We are still studying Idris' genes.

The problem is, we only have a tiny amount of the osprey genome sampled so far and it is not very variable. Consequently, we can only look at a handful of genes, which themselves only have a handful of alleles (a variant form of a gene), in our ospreys.

Think of each osprey gene as a cone of ice cream that could have many different flavours... vanilla, chocolate, raspberry ripple, toffee, mint chocolate chip etc. It's still the gene for ice cream, but potentially has many different forms (flavours). The more of these flavours we know about, the easier it will be to make a determination about Idris' provenance, without actually having the ice cream directly from Idris himself (we sample only his chicks) to compare to.

Idris will only pass on one ice cream flavour (allele) to each chick - the other coming from Telyn (or his previous partners'). So they could be the same: two raspberry ripples to both Teifi and Tywi, for example.

To make matters even more difficult, these flavours don't exist in equal amounts. Passed down from their ancestors via thousands of generations by random chance, there could be, for example, 95% vanilla in the ice cream gene and just 1% each of all the other flavours.

Therefore, to confidently answer the question about Idris' origin, we would have to be able to look at all the flavours on Idris's chart and compare it to the other ice cream charts in Wales, England, Scotland - maybe even Continental Europe (the charts don't exist, of course.. not yet anyway)... or we could wait for the ice cream van to come round again. Problem is, the ice cream van only comes round once every summer.

Coned in... we need to see more flavours. 


So, in a nut shell, we don't really have enough data yet about Idris' genes to make a firm assessment of his history. Once the Idris ice cream van returns again next July, we will hopefully have more flavours to work with. Vegan options also available.


The Broader Welsh Osprey DNA Research

I'm delighted to let you know that the results of the genetic work we have been doing on the Welsh osprey population over many years has been accepted this week for publication as a scientific paper (these things take a loooong time in the peer review stage).

Once the paper is published in the Journal of Raptor Research later this year, I will let you know. There are some very interesting things coming out of all the work we've done over the years. My various hypothesis over the years have been rigorously tested and this paper will show us the results.

And Finally

We owe a huge debt of gratitude to Ilze, Niall and Dr. Helen for doing this osprey genetics research. Studies like this cost a lot of money, but the guys have done the work pro bono, often in their own time.

Ilze helps out with recording chick weights at the 2020 Teifi and Tywi ringing

We are discovering things about ospreys that were unimaginable just a few years ago. This is our osprey equivalent of the Higgs boson in physics, the God particle (or gene in this case) that can tell us things about osprey ecology and evolution that have, up to very recently, been hidden away deep inside the osprey's biological vault.

We can, for the first time, delve deeper and peer into an osprey's inner-workings, the ingredients list of life, and look back in time over thousands of generations and millions of years.

Idris: Look deep into my eyes...

And the beauty of this work? It costs each osprey just a drop of saliva and 10 seconds of its time for information that will, ultimately, help in their conservation and start to right so many of the wrongs of the past and the way we have treated them over millennia.

DNA research takes time though, and money. This is just the start of the journey. Patience is the Mother of success.

Thanks for your time, boys. See you again next year...


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