Posted: Thursday 23rd June 2016 by Emyr MWT

Our two chicks are 30 and 25 days old today - both are absolutely flourishing

The chicks are almost as good as their parents with regard to body heat regulation now. Not only did these two inherit Monty and Glesni's genes that will make them look like their parents - they also picked up some handy behavioural genes as well.

Here's one of these behaviours - it's exposing their gular region (Gula - Latin for 'of the throat') to any breeze that might be around.


This increases evaporation which will lead to a slight loss of body heat. Some birds, cormorants for example, will actually flutter a part of the throat (usually a membrane) to increase the effects of 'gular fluttering'. Many birds use this technique when it's hot.

This is exactly the same principle as feeling cold when you step out of the shower. As the water on your skin evaporates, it makes you colder. Panting in dogs is exactly the same.

The Dyfi ospreys were featured once again on the BBC's Springwatch 2016 show this year. Many European fans as well as those from further afield were not able to watch or download Springwatch, so here are the two articles rolled into one video feature:

 

Staying with the genetic theme, we have been working behind the scenes recently with the BTO and others to enable us to undertake buccal (mouth) swabs this year on the chicks when we ring them in around 10 days time.

Around 10% of osprey chicks are misidentified each year as the wrong sex - it's not an easy task to undertake when they're ringed at just a few weeks old, with many overlaps in parameters between males and females. The DNA research will allow us to get their sex right 100% of the time. But we'll find out a lot more than just gender.

Over time, we hope to draw up a family tree of ospreys in Wales. There are eight adult birds currently breeding in the country in four nests and only one of these is ringed - Glesni. Are some of the other seven ospreys related to each other? Where have all the unringed males come from?

 

The Dyfi family tree - does Monty have brothers?

 

It would be pretty unusual for a Scottish male to set up home 300 miles south of his natal area, but not unheard of. But all four - 100% of them? They don't come from Rutland that's for sure - all of Rutland's chicks are ringed in the nest. Almost all Cumbrian and Kielder ospreys are ringed too.

Genetic analyses will allow us to build up a clearer picture of the degree of 'consanguinity' between birds. In other words, a coefficient of relatedness between individuals, or simply, how closely related are they? In a small recovering population like we have in Wales, the results from these DNA swabs could yield important information as to the population dynamics of such a small colony and better help us create conservation plans for them.

Many other European countries have very small populations too, hopefully beginning to recover again. Despite not having a football team in the Euro-Championships at the moment, the Netherlands are the latest country to attract breeding ospreys after a void of many centuries. Osprey populations in Spain, Portugal, France, Germany and now the Netherlands, are all on the increase. One day, hopefully, these small fragmented populations will start to expand and as they do, they will meet each other resulting in one large pan-European population again as must have occurred a thousand years ago.

A robust population of individuals with free (genetic) movement across invisible borders and barriers with no constraints or restrictions to migration, resulting in one large healthy population. Maybe there is a lesson here for us all?

 

Youngsters

Talking of migration, we have news of a pair of two-year-olds to bring you.

A 2014 male was photographed in Kent at the beginning of the month. This bird was ringed with the second (of two) digits being 'R'. Four young Welsh ospreys were ringed with R rings in 2014: Gwynant and Deri from the Dyfi as well as another two from the ON 4 nest in Snowdonia. Could it be? Keep looking up!

And over the weekend photographer Andy Davis photographed this bird fishing at a north Wales reservoir.

 

She is a Scottish 2014 bird from Ayrshire named 'Elsa' - her Darvic ring is on her left leg, Blue CX 7. (Thanks Andy and Sue C)

She's very light for a female - is Elsa a male? We've asked John Wright at Rutland to have a look for us.

 

Calendar

So the search has begun for the best images of this season for the 2017 DOP calendar - here's the first contender taken a couple of days ago.

Monty

 

Talking of dates - best of luck to Wales, England, Northern Ireland and the Republic of Ireland at the weekend. All four countries have made it through to the last 16 of the Euro Championships with Wales topping their group.

The Dutch needn't rue missing the Euros this time around - this year they have a much more important part to play in the grand European scheme of things...

 

 

 


 

Read Emyr MWT's latest blog entries.