Thursday, November 08, 2018

The rise and fall of wildlife since 1938

For a long time I have thought about the many changes in British (and other) wildlife during the course of my life, increasingly stimulated by the growing number of accounts of environmental catastrophes and massive declines in biodiversity.

I was born in 1938 and will be 81 next year.  I seem to have been interested in natural history since very early childhood, partly encouraged by my parents and other family members and there have undoubtedly been many changes in wildlife as I have interacted with it over the years.

I will need to write this in dribs and drabs as I remember things and try to get them into some sort of order, so please, if you are interested, re-visit from time to time to see what I have added.

I was born in Chingford, then in Essex, now in north east Greater London and lived there until I was twelve.  Vast tracts of Epping Forest were within easy walking distance of our house and I spent much time exploring there.

A friend, David Smith, and I were very interested in butterflies and moths and enjoyed trying to raise the adults from caterpillars.  We could collect dozens of different species from sloe and hawthorn bushes on the forest plains and used to find suburban poplar trees very fruitful too.  They nearly always had puss moth eggs and larvae, poplar greys and poplar kittens.  On suburban willow trees we found red underwing larvae and once a lobster moth caterpillar climbing a beech trunk.  The pollarded limes along our road (The Green Walk) often had lime hawk larvae heading up or down and I found eyed hawk caterpillars on our garden apple trees.  Once I went with a school friend to stay in Linton in Cambridgeshire and saw dozens of privet hawk larvae busily trimming the roadside privet hedge.  That was the last time I saw an early stage of this species.

Despite frequent searching of likely looking trees and shrubs around our present home in East Sussex, I rarely find caterpillars or see the feeding damage they cause as a sort of indicator on where to look.  It is not surprising that many insectivorous birds and bats are struggling and the more they find now, the greater the pressure on surviving populations.  What is usually described as a downward spiral.

One group of moths that seem to be doing better is those that fly in winter: November moths (Epirrita spp.), the winter moth (Operophtera brumata) and the December moth (Poecilocampa populi), for example.  This year, 2018, November moths were particularly common on lighted windows with often ten or twelve scattered across the panes.  Winter moths were less frequent and I saw a December moth settled on the wall of the house, the only moth I have see in such a situation all year.

Moths used to be much commoner in the warmer months and I would make many records from those attracted to our lighted windows, but now I am likely to get only one or two a month although the surrounding environment seems to have changed very little.  I wonder if the large number of acres of land farmed in the modern way has reduced the insect population such that bats and insectivorous birds are more active in woods, along hedges and in gardens than they used to be thus reducing the numbers of moths etc in those places in the warmer moths but having less effect on the winter-flying species during the period when the bats are in hibernation and many birds on migration.

Birds are quite an interesting phenomenon.  In the past we could hear, from the house, nightingales and grasshopper warblers in full song during the nesting season every year.  There were large numbers of chaffinches, greenfinches, house sparrows and starlings, and various other small birds that visited the garden, but most are now absent.  Blackbirds, thrushes, robins, woodpigeons and hedge sparrows are still always present but now we also have buzzards mewing regularly overhead and there are occasional sightings of ravens, both species that had been missing from this part of Sussex for many years.