Early on Tuesday morning, July 15th, both the osprey chicks were ringed, weighed, measured, sexed and named. We have one male and one female.

We placed one plastic (Darvic) ring on the right leg (left leg in Scotland) and a British Trust for Ornithology ring on the left leg. The Darvic rings were Blue 3R and Blue 5R and these were placed 'reading up' - that is, the number nearest the foot.

(Above: We had some help this year with announcing the names:  Nia, Arron, Jody and Joe, from Ysgol Gynradd Machynlleth explain all..)

As we had suspected for some time, the first chick to hatch was a male, and the second a female. But why had so many people guessed correctly this year?  Two main reasons really:

1. As soon as adult feather development started in earnest, the first chick seemed to be growing particularly white feathers. Not always a 100% indication of gender, but certainly a clue. Conversely, the younger chick had, by comparison, very dark feathers.

Deri - much darker plumage around the eyes and head generally

2. Chick No 2 was catching up to her brother in size from around three weeks old. By the time they were ringed at 37 and 34 days old respectively, the younger chick (by 3½ days) had caught and passed her brother. A sure sign she was a female. In most birds of prey species, the female is heavier/bigger than the male.

Which names to choose?

We name the osprey chicks after Welsh Rivers every year. It seems appropriate considering their ecology and it is non-political. As always, we test them out in terms of pronunciation on volunteer, Posh Pete.

Most name suggestions he pronounces are greeted with fits of laughter and applause, so this year we bought a Clap-o-meter off Ebay. It had apparently been used in a gameshow in the 1970's. Those names (not many) getting a Clap-o-meter reading of over 50% were placed on a shortlist. So here are the two that were chosen:

(Sorry Pete, we couldn't put Afon Pontrhydfendigaid in the shortlist. We hope you found those two teeth you lost)

Deri: A river near Corris, just a few miles up stream and a tributary of the Dyfi River.

Gwynant: Meaning white stream. Appropriate of course as the first chick has particularly white feathers and he hatched from a very white egg with hardly any spotting (maculation).

Statistics

Here are the up-to-date stats for all the Dyfi osprey chicks so far:

And a key event record:

Ringing - 10 Things We Didn't Know Last Week

1. We shifted the ringing one day forward, mainly due to rain forecast and very high tides. The weather was perfect - no rain, warm, and overcast.

2. On Tuesday morning we waited until both chicks had fed and ensured that both parents were around. Glesni is much less agitated when Monty is also around.

3. We were at the nest for 35 minutes, Monty and Glesni were off the nest for 46 minutes in total.

Glesni circling the nest

4. During this time both Glesni and Monty were circling the nest, occasionally calling. The alarm calling is not directed at us, but is a communication to the chicks to 'play dead' (thanatosis). This is their best form of defence if a genuine predator was around. The chicks blend in extremely well and by not moving, their camouflage is an excellent form of mimicry and renders them close to invisible. This is why they are so placid and easy to ring.

Deri - Thanatosis in action

5. Gwynant weighed 1,520g and Deri 1,600g. Deri was 5% heavier than her brother despite being 10% (3½ days) younger.

Tony weighing Gwynant

6. Both Gwynant and Deri's feathers looked in great condition with no 'fault bars' which occur during a stressful period in their growth - malnutrition usually. The bronze-coloured tips to the feathers helps the chicks with their nest camouflage, but will gradually wear down over the next 18 months before the feather is moulted and a new one grows. The new feather (and subsequent ones) will not have this bronze edging to them.

7. Also over the next 18 months, Gwynant and Deri's eye colour will change to yellow as they become adults. However, if Monty's dark orange eyes have a genetic factor, who only knows what colour they might be in a few years!

Gwynant - will his iris colour change over time?

8. There is absolutely no truth in the rumours that ring Blue 4R has been lost down a sofa and has since fused with one of Janine's discarded Maltesers. It will be used next year.

9. Gwynant and Deri will migrate to Africa, or possibly southern Europe, and return in two to three years' time. They may live to be over 30 years old. Hopefully, this half an hour encounter with humans will be the only contact with people they have at close quarters.

10. Ospreys are gorgeous birds. They look stunning in photographs and videos, but up close, in real life, they are indescribably beautiful.

Gwynant

Thank You

As always, we would like to thank bird ringer extraordinaire, Tony Cross, for ringing our osprey chicks for us. These are highly protected, Schedule 1 Birds of Prey and Tony goes about his work with the utmost level of diligence, professionalism, and efficiency. He has a knack of making the whole process look effortless and easy. Ringing ospreys is neither of these things.

Many thanks also to Chris and Alan of the ringing team and Alwyn and Janine back at the visitor centre and Observatory. Alwyn and Janine coordinated the camera work and kept everybody on Live Chat updated as the birds were being ringed.

Video

This year's video is a little bit special. It was recorded in Ultra High Definition - or 4K definition. This has four times the amount of resolution and clarity than regular HD. We think this could be a world-first for ospreys!

True, there aren't that many 4K monitors out there yet, but they are coming. Some smart phones and TVs already have 4K screens. So, the video is future proof - when you come back in a year or two with your 4K monitors and laptops, you'll be amazed!

If you want to see the video in 4K, press the YouTube icon and then select 4K resolution. Alternatively, you can see it in the 360 Observatory in all its 4K glory.

It looks out of this world!