The three chicks are around a fortnight old today - 16, 14 and 12 days old to be precise.

They have made it through those first 10 days of life relatively unscathed and now have an excellent chance of finishing the race - fledging in another five weeks and migrating to Africa a few weeks after that. I am always apprehensive about these first 10 days; just like most animals, it is these first few days of life that are the most precarious and present the greatest obstacles to making it through to adulthood.

It is also during these first few days of an osprey's life that we stare incessantly into the nest, wanting to reassure ourselves that everything is okay, that all the chicks are healthy and getting their fair share of food. Of course, any decent osprey mother would share the food out evenly and fairly, giving her chicks the greatest chance of surviving. Well, not quite.

Me, me - I'm next..

In the DOP office we have an Anthro-Box. It's like a swear-box but the crime this time is blurting out something a tad anthropomorphic. It's at this time of year it gets filled the most. Kerching!

Here's the problem. We are all human, so we look at the world around us in a human way. Simples. It's our default setting, the factory setting that we base our lives on. It serves us well in everyday life when interacting with other people, but things start to break down when we look at animals and apply the same factory settings to them. We need a disconnect - a way of not looking at nature through just one species' perspective, but by something else.

That something else is a 'rule'. Just like a mathematician can throw any amount of numbers into an equation and get the right answer because he or she has a 'rule', or a physicist can work out the density of an object by not even being able to touch or see it because of another 'rule', a biologist should be able to look at a few behaviours of another animal and, once it's been through the rule book a few times, come out the other end with a few observational answers.

The Biology rule book wasn't written by Issac Newton, or Albert Einstein or Archimedes, it was written by Charles Darwin. He wrote it over 150 years ago (with some help from a few 'friends') and the name he gave his book was "On the Origin of Species by Means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life".

Darwin was good with biology, but he would have made a rubbish Marketing man. Today we call this mouthful, 'natural selection', or simpler still, evolution.

June 14th. A mother, a fish and plenty of decisions to make.

"Glesni is not feeding her smallest chick"

"Chick 2 didn't get any food that time"

"She always feeds her eldest chick first - it's not fair"

All these 'allegations' may be true! But let's try and give the Anthro-Box a day off and throw all this stuff into our 'rule book'. Why would Glesni (or Monty for that matter) clearly discriminate between the chicks, usually favouring the eldest offspring or the next one down?

Well, it's pretty simple really. Evolution works on a genetic level - it's a numbers game. Her main goal in 2015 is to pass as many of her genes into the next generation as possible. This is called fecundity.

In 2013 and 2014 Glesni had a fecundity of two. Working in partnership with Darwin's natural selection, both Glesni, Monty, and evolution decided that they would only lay two eggs; three is much more normal. It was decided that if they laid a more conventional clutch of three eggs, the lateness in the season (in 2013) and severe disruption from Blue 24 (in 2014), would disadvantage them so much that all three eggs/chicks could be compromised to such an extent, maybe none of them would survive due to these environmental factors.

As it happens, working in partnership worked out for them. In both years, two eggs became two chicks which survived to migration age. (Of course, we will never know what would have happened if three eggs had been laid - evolution doesn't allow us control experiments).

So what has all this got to do with chick feeding?

Nature's Way: So that will be one for me, and one for me..

Well, it's the same principle really; the genetic numbers game ain't finished yet.

Decisions on whether to lay two or three (or four) eggs are taken based on history - what has happened to the osprey's life already. Decisions based on which chicks to feed are made based on what may happen in the future.

What would happen if the river froze over? What would happen if Monty got injured and couldn't catch fish for several days? What if Blue 24 started to interfere again and disrupt the whole apple cart? An unseasonal southerly trajectory of the jet stream anyone?

Blue 24 has kept her distance so far in 2015, although she did pay a quick visit on 9th June

Evolution has worked out an answer based on what has worked best in the past. If one of the above scenarios did indeed happen, or a thousand other examples you can think of that would stress the 'fitness' of a nest, only the strongest chicks(s) would survive, if at all. It is much better to have a tapering scale of chick strength (fitness) in a clutch of three - they can't all be fed simultaneously at the same sitting anyway due to their size and proximity to the parent bird. The biggest bird (usually the oldest) will dominate its siblings and commandeer the first bits of food. If adversity comes, it has the greatest chance of surviving. We've all heard of the phrase "survival of the fittest" (although it wasn't Darwin himself that coined it); here's a good example of it.

If Glesni chose the human approach to feeding her chicks by trying to be as equitable as possible, she would end up having three chicks of medium fitness, the smallest continually playing catch-up - a two-day summer storm could kill the lot. However, if she had one very strong chick, it may well survive the storm at the cost of its two siblings. This is an evolutionary strategy - a genetic numbers game, only Glesni and Monty don't make up the rules, their ancestors did - millions of them.

Feeding osprey style - it's not 'fair'

Of course, if we don't have a bad storm or any other kind of traumatic event, all three chicks should survive. All that discriminatory feeding and preferential treatment to the biggest chick that shouts loudest will all have been in vain - an insurance policy that was never claimed on. Job done.

I remember missing out on our annual Sunday School trip when I was around eight years old. All my mates went to Rhyl and I couldn't go because the bus was full - I felt so sad. However, my Nain saved the day and took me to Butlins in Pwllheli instead on the bus. It actually turned out to be a much better option - we had fish and chips and a Knickerbocker Glory and I got to play on a full-size snooker table all day.

Fear not for smallest chick, Bobby Bach; nature has worked out a journey for him. Like me, he probably doesn't like candy floss anyway.

Okay - who's next?