Posted: Sunday 28th April 2019 by Emyr MWT

Easter this year was the hottest on record.

Fast forward eggsactly a week and we experienced a ferocious Storm Force 10 weather event on the Dyfi with temperatures down to freezing and winds gusting over 80mph. And our friends overseas wonder why the Brits are always talking about the weather!

By Friday afternoon we knew that Telyn's clutch this year was going to be three eggs - same as last year.

A trio of eggs again in 2019

 

Four-egg Clutches

Ospreys can and do lay four eggs, probably around 3-5% of all UK breeding females will lay a quartet of eggs, but three is by far the norm.

For a four-egg clutch both birds need to be back at their nest site early in the season, be established with each other, have good weather, a continuous food supply and a dollop of luck. Sometimes all four eggs will hatch and all the chicks survive to migration age, but a whole set of optimum conditions need to be in place for this to occur.

A four-egg clutch at Boulder County, Colorado

The Four-egg Paradox

We've had a combined 40 years' worth of osprey breeding in Wales this century spread over six nests. As far as we know, not one of these nests has produced more than three eggs in one year (notwithstanding 2015 at the Glaslyn - an aberration year due to the female laying seven eggs with several males being around following the failure of her established male, Ochre 11(98), to return).

So you'd eggspect at least one, maybe two, four-egg clutches in that time? It hasn't happened.

However, there are plenty of eggsamples of Welsh-related ospreys laying four eggs. Three Glaslyn birds have, in fact, had four-egg clutches:

 

  • Yellow 37 + Unringed Female 2015

Four eggs - First known four egg clutch in England/Wales.
Intruder attacked unringed female as she brooded the eggs, one accidentally displaced from nest cup. Three chicks hatch, but one subsequently dies.

 

  • White YA + Unringed female 2016

Four eggs - Four chicks hatched, four chicks raised to fledging age.

 

  • White YA + Same unringed female 2017

Four eggs - Three chicks hatched and raised to fledging stage, egg three probably the non-surviving chick. Camera failure occurred during incubation period and not fixed until chicks had hatched.

 

  • White YA + Same unringed female 2019

Four eggs

 

  • Black 80 + Blue KC 2016

Four eggs - Four chicks hatched and raised successfully to fledging stage.

 

A four-egg clutch at Kielder in 2017 © Forestry England

Many thanks to Joanna and Heather for help compiling the data.


Storm Hannah

Usually when we have storms, and named ones at that, in the UK, the media are all over them. Storm Hannah seems to have crept in without much fanfare - at least as far as I could tell.

The first I knew about Hannah was a comment by one of our followers on the DOP Facebook page on Friday morning. By Friday night, this storm was as serious as any storm I'd seen on the Dyfi.

Hannah making her way in from the Atlantic

 

As the sun went down everything seemed normal, just a bit gusty with winds up to 50mph forecast in the early hours.

Telyn incubating her three eggs on Friday evening


By midnight, however, it was obvious Hannah was no 50mph storm. It was chillingly cold with wind speeds by now gusting over 60mph.


Telyn protects her three eggs in a terrifying April storm

 

Gusting over 80mph Telyn is battered by parts of the nest becoming dislodged

The osprey nest was not the only dwelling to be damaged by Storm Hannah, our DOP visitor centre also took the brunt.

We get to work making safe several trees that had blown down before opening at 10am

Despite being ferocious, thankfully Hannah didn't stay too long. By mid morning we were down to 50mph winds again and by the time the power was restored mid-afternoon, she was down to a much more manageable 20mph.

We're also thankful that Hannah came in late April and not late May when we'll have, hopefully, small chicks. Day-old chicks and storms really don't go well with each other. Let's hope we don't get one of Hannah's siblings until the autumn now.

Here's a quick video of how Storm Hannah came through the Dyfi yesterday morning:

 

As always, a massive thanks to all the volunteers, egg-watch and engagement folks, that were simply brilliant over the weekend. We couldn't do this without you.

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