While I agree with the analysis and explanations provided by Dr Alexander C Lees (Feeding birds in our gardens is a joy but it may be harming weaker species, 25 August), it yet again places some responsibility for the decline in species diversity on the shoulders of well-meaning households feeding birds in their gardens. Surely the elephant in the garden is the agricultural system in Britain, which has resulted in the removal of hedges and the concomitant loss of nesting sites, for example. It is disappointing that this contributory factor was not mentioned.
I will continue to feed the birds in my urban garden and enjoy the many varieties that use the feeders.
Alison Powell
Manchester