Since I began writing my weekly Nature Notes column nineteen years ago, there have been many changes in the natural world, some subtle, some dramatic, a few welcome but many of major concern.

Some of the problems involve invasive destructive species such as a range of tree diseases and harlequin ladybirds to name but a few.

In that time span populations of spring migrant birds including swallow, swift, cuckoo and warblers have on average halved. Similar situations apply to countryside birds such as skylark, yellowhammer and lapwing.

Fortunately, some species have increased; notably jackdaw, goldfinch, chaffinch, coal tit, buzzard, red kite, peregrine and a relative newcomer the little egret, all welcome of course except for the parakeet!

Bees, moths and butterflies have suffered with even small tortoiseshell (pictured) and peacock classed as endangered. There are several reasons for such declines, too many to list here but changes in land use and management, chemicals and weather changes are notable causes.

Not wishing to dwell on negatives, we can rejoice in the fact that rivers and waterways are much cleaner and pollution levels lower. Two notable success stories involve local waterways. 

Beverley brook, classed twenty years ago as an open sewer is now thriving and I have recorded eight species of fish in the past fifteen years. Damselflies, once absent, are now well established.

The river Wandle is also a major success. Trout are present in good numbers which clearly illustrates how pure the water is now as this iconic fish, once angled for by Lord Nelson and Izaac Walton requires well oxygenated swift flow to survive.

Lets hope that during the next nineteen years, we will see fewer declines and more good news for our precious wildlife.