IN AMONGST the dark, clawing mud banks of the River Devon estuary at Cambus, a small white, heron-like bird stalked the shallows, its head bowed in rapt concentration as it searched for small flounders.

It was a little egret, and the first one I had ever seen at Cambus, although I have encountered these enchanting birds on several occasions further down the Forth at Skinflats near Grangemouth.

One might think that the little egret is more closely associated with the marshes and lagoons of the Camargue in the French Mediterranean, or in the Algarve in Portugal, than here on the mud banks of the Devon estuary.

But this most delicate and attractive little snowy-white heron has undergone a quite phenomenal northwards expansion in range over the past 30 years or so that has seen it become an established breeder in England and Wales and a regular visitor to Scotland.

The reasons behind this astonishing range expansion are uncertain, but it is thought to have been facilitated by changes in our climate and it is probably only a matter of time until they start nesting in Scotland.

I imagine also that the little egret has benefited by conservation initiatives in continental Europe and the UK to enhance wetlands, which has further boosted their numbers.

The story of the little egret is a graphic example of the constant ebb and flow of nature, which nowadays is controlled ever more strongly by the hand of humanity.

The little egret is a beautiful bird and a welcome visitor, but would it be here now without human-induced climate change?

It is hard to be sure, but it certainly does not seem to have ever been recorded in Britain in the more distant past, and is a new coloniser, rather than a bird returning to recover lost haunts.

Other than the little egret, the estuary at Cambus was relatively quiet for bird life, apart from a few slumbering goosanders, some moulting mallards, and a lone female teal.

However, late season summer flowers brightened the track verges, including drifts of purple-bloomed knapweed, and the yellow, nodding pin-cushion heads of tansy.

Their vibrant colours lifted the heart and were a wonderful swansong to this end of season natural plenitude.