Flown the Nest?

The RSPB has estimated, on the basis of its surveys, a 44 million reduction (roughly 1 in 5) of breeding birds in the UK since 1966 (http://www.guardian.co.uk/environment/2012/nov/19/uk-breeding-bird-population-decline?INTCMP=SRCH). House sparrows, Wrens, Willow tits and Arctic skuas have all shown big declines but some species, including the Chaffinch, have increased breeding activities. The results are not particularly unexpected as there have been big changes over these 40+ years in the UK human population, agricultural practises, urbanisation, pet keeping, gardening practises (including converting land to car parking), waste disposal, increased survival (by eating human waste) of crow family members (with propensities for eating the eggs and chicks of 'song' birds) over winter periods, possible climate change impacts on seasonality of fruits and insects etc etc, Chaffinches may have partly benefited by their efficient utilisation of bird feeders (an option not available to all species). I suspect that the reasons for declines in different species will vary but the basic trend is for a further impoverishment of the UK biodiversity.