My grandparents, Gertrude and Albert (known as Old Smoke), lived on Horsey Island (Country diary, 24 June) in the early 20th century. My mum spent her childhood catching shrimps and looking after her donkey, charging any visitors a penny a ride. Old Smoke, a thatcher, was a guide on the marshes, but even he was once overtaken on the causeway by the tide. Perhaps he was returning from the pub. His horse and cart were lost, but he escaped on a second horse, which had been tied behind.
David Brayne
Evercreech, Somerset

How reassuring it is to discover that, at a time when climate change denial and cuts to foreign aid figure prominently in US policy, funds can be found for a researcher to spend 10 years decoding the chirps of zebra finches (Report, 26 June). Let’s hope the finches can warn us when it’s time to head for the ark.
Roderick MacFarquhar
Edinburgh

I firmly believe that Margaret Thatcher based herself on the comic character Margo Leadbetter in the TV sitcom The Good Life (Penelope Keith obituary, 29 June). She had the same manner and attitude to those she employed.
David Prothero
Harlington, Bedfordshire

Re memory tests (Letters, 30 June), I remember long, long ago, the question was “Who is the reigning monarch?” The answer more often than not was “Margaret Thatcher”.
Dr Christopher Calman
Stroud, Gloucestershire

Prof Rebecca Clifford (Letters, 26 June) suggests we log ancient trees on the Woodland Trust’s inventory. Surely this would be totally counterproductive.
Reg Hand
Derby