Thursday 28 April 2016

The 2016 season gets off to a chilly start

I published some research in the BDS Journal that suggested dragonflies' emergence patterns are only affected by temperature when it is a warm spring, in which case they emerge early, In cold and "normal" springs, emergence is usually at around the same time. This was supplemented with more research that suggested emergence is stimulated by UV levels rather than temperature, so a warm spring is likely to have higher UV than a normal spring.

Well, to add to my theory this spring has generally been cold, with average temperatures in April being lower than in December. It actually snowed here yesterday. Judy and Terry Wood reported the first Large Red Damselfly emerging from their garden pond in Polebrook on 27 April which closely matches their previous first emergence dates from this pond. This weekend looks warmer with more sunshine so I'll be out and about hunting for more.

Female Large Red Damselfly, Polebrook