It took five days and three major attempts at regaining her Dyfi nest before Glesni overpowered Blue 24 and dethroned her cousin. It was spectacular and dangerous, it gave thousands of us watching an innermost insight into the world of osprey behaviour, a world we rarely see this close up.

Blue 24 - determined and steadfast, she would not be giving up her new nest easily

As soon as Glesni returned from migration on the morning of April 10th, two days after her orange-eyed mate, it was clear that her cousin, Blue 24, was not going to relinquish the nest without a fight. Glesni’s first stab at regaining her territory and mate was relatively tame and short lived. She had, after all, just completed a long migration of a few thousand miles.

Her second attempt was delivered with much more gusto and zeal. Clearly, Glesni’s strength was returning and both birds knew it. They disappeared for hours on end with several sightings of them around the Dyfi, each female circling around the other as if they were sizing each other up.

Then, five days after Glesni's return, all hell broke loose.

Both Glesni and Blue 24 had grappled for supremacy and it was far from obvious who would eventually succeed. They were evenly matched both in strength and determination - there was only one way to sort this out. What we managed to record on April 15th would stun even the most assiduous of osprey students.

Here are the highlights of the amazing action of April 15th, condensed into less than four minutes, one female osprey displacing another and all captured and recorded. Put your seat belts on...

We haven’t seen Blue 24, or Dai Dot for that matter, since. Both Monty and Glesni have been bonding and mating - all the usual stuff you would expect, just as if nothing had happened!

But what can we learn about osprey behaviour from the events we witnessed during the week April 8th to 15th? Monty quickly ushered Dai Dot off his patch the moment he returned, one piercing look seemed all that was needed. Having been around for several years of course, Dai knew the score. This was Monty’s nest and piece of the Dyfi estuary, he had no intention of starting a war with another male, much better to save time and possible injury, up sticks and look elsewhere. Surrender was Dai’s best strategy to get his genes into another generation.

So why was Blue 24 much more reluctant to capitulate? After all, she also had been around last year and witnessed first hand Monty and Glesni on this nest, alongside two huge chicks - Clarach and Cerist.

Blue 24 visiting as a three year old in 2013

It’s exactly because Blue 24 saw first hand last year a virile and productive nest that she was so determined not to let go. She had invested over two weeks of her time this year into this nest - she had been the first osprey around on the Dyfi after all, arriving March 31st in fact. Her research studies of last year were paying off, she had found a good nest with a proven track record of producing chicks, returned the following year only to find that neither of last year’s tenants were around - just a single, unpaired male. Jackpot.

Maybe there’s something else to understand in all this too. It’s the actual nest site that is of much greater importance to female ospreys rather than the male occupying it.

What a difference a week makes..

A male osprey could be the best provider of fish in the world, but that’s no good to a nest situated far from water and food, in the middle of a forest teeming with goshawks and eagles.

There is no romance or sentiment here. A male osprey’s job is to find a suitable area for a nest and then build or inherit one. Get it wrong and his days of remaining a bachelor are long and fruitless. Get it right and the list of descendants promises to be long and diverse. It’s the female’s job to choose a mate, or rather, nest site. Thereafter, the male is merely the provider of a few fish for five months and some DNA for a few days in March and April. Job done.

As soon as Dai Dot vanished down the Dyfi estuary upon Monty’s return, Blue 24 was mating with Monty quicker than you can say piscatorial cuckoldry. No pining, no long-lost love stuff, no hiraeth. Just a determination and strong-mindedness to get her genes into the next generation.

Natural selection ain’t pretty sometimes, but it works. For some.

Together, at last