A WEEK of good news, bad news. My brown trout fishing season has opened, a day more important to me than Christmas or any birthday. That's the good news.
The bad news is that I also received warning of a soon to be published survey that will show that a unique British bird, the acrobatic yellow wagtail, is in decline in most places - and in steep decline near our waterways.
For me, both events are interlinked for a family of yellow wagtails - Waggies, I call them - have been my trout fishing friends these past 30-odd years. And my pet theory, based on close observation, is that the declines in both wild-trout and Waggy populations have the same cause.
My first encounter with the Family Waggy was nearly fatal. I was wading in a fast current under a bridge over the River Lune when I grasped at the rough stone for support - only to be scared half-to death by a high-pitched, bad tempered scream in my ear and strange creature flapping aggressively not six inches from the end of my nose.
A Yellow Wagtail
Backing away with some difficulty - two-foot-deep fast flowing water is no easy medium for fast manoeuvre - I saw that my assailant was Mrs Waggy, who was now settling back onto her nest where she was sitting on a brood of half a dozen tiny chicks. I had very nearly crushed the nest with my clumsy mitt.
Ever since, I have sat on the bank eating my snap for many a joyful hour watching the parents of successive generations snapping up hatching flies from the surface with a skill bettered only by swallows and the sand martins which nest down river.
But here's the rub. The British Trust for Ornithology has carried out a survey shows that the yellow wagtail - a bird which is virtually unique to the British Isles and therefore hugely important scientifically - is in decline.
Even worse, the species is officially in "steep decline" by our waterways. And I think I know why.
My trout fishing was also in steep decline until four of five years ago, too. The reason: the flies that feed the trout, the wagtails and myriad other birds were no longer hatching.
And as Mother Nature had organised things so that the biggest fly hatches came just at the time when the Waggy chicks were in the nest, their principle supply of baby food had dried up.
There was little doubt that some form of pollution, quite invisible to the naked eye in such a pristine river, was at work. But what? Was it an overdose of phosphates and nitrates from artificial fertiliser? Or, even worse, the effluent from silage clamps, which contains several poisons extremely toxic to marine life.
The owners of the riparian rights on our stretch of the Lune are, fortunately, extremely conscious of this wonderful environment. About ten years ago, they gave up dairy farming in favour of sheep, which meant using far less fertiliser and an end to their silage clamps.
Since then, the flies have come back, the brown trout are bigger and more plentiful - and, this weekend, I hope the current Waggies will be at work building their new nest under my favourite bridge.
But they and I are lucky. The story is not the same elsewhere. Indeed, the Yorkshire Dales National Park is conducting a survey to find the cause of the rapid decline of wagtails in an area where industrial pollution is virtually zero.
Now this is not another attack on farmers. I have written much in their support in the past. But I do hope that the present crisis in agriculture will eventually produce a system of farming which uses fewer and fewer chemicals to pollute our rivers and streams.
That way, Waggy and Co might stage a come back - and all our countryside will be much the better for it.