The Woodland Trust’s Nature’s Calendar project has received over 64 records of early spring activity that started in November 2018 – including insects that have been spotted active up to 5 months earlier than normal.
Mild weather seems to have temporarily disturbed insects from hibernation. A small tortoiseshell butterfly appeared flying outdoors on Christmas Day in Merthyr Tydfil, and a red tailed bumblebee on Boxing Day in Somerset. The average date for small tortoiseshells is 14 April, and bumblebees 26 March – making both over three months early. Even earlier still, a red admiral was seen on 17 December in Cambridgeshire; the average emergence date is 7 May, making it nearly five months ahead of schedule.
Even birds have made an early appearance. The song thrush has been heard in eleven locations since 5 December and is increasingly reported singing all winter, though expected mid-late March. Blue tits were also seen exploring a nesting box on 26 December, though the UK average date for nesting is 4 April.
Met office records for the UK report both November and December as mild, with average temperatures more than 1°C above the 1981-2010 long-term average2. However, with a potential cold snap on the way, more delicate species could suffer.
Dr Kate Lewthwaite, citizen science manager for the Woodland Trust said:
“Once again – despite being in the throes of January – flora and fauna are reacting to milder climates, and spring seems to have sprung early. We were far from a white Christmas, with hazel flowers and snowdrops being spotted by our citizen scientists across the UK.”