Mild winter butterflies

[J.B.Murray (John Murray)]

Talking of mild winters, last Friday (Feb 13th) temperatures reached 18.9c at
Marshalls Heath, and up to 19.6c at other locations in southeast England.  After
getting one or two phone calls and seeing 2 Brimstones at the window, I went and
walked the Marshalls Heath transect to see what turned up.  The total was 7
Brimstones (Gonepteryx rhamni) and 1 Small Tortoiseshell (Aglais urticae) in 33
minutes.  

This total would be good for the middle of April, let alone February.   I can't
remember such a day so early in the year since 14th February 1961, when similar
numbers of Brimstones were on the wing in our garden in Surrey.  However, the
difference is that in 1961 this particular day was a one-off; the following day
and the previous day were cloudy and cold, whereas there have been butterflies
on the wing (4 species in total) reported every day now since 12th February, and
there had been 4 or 5 days previously this year when butterflies have been
tempted out in this part of the world, the first on January 7th.  There can be
little doubt that the present spell of mild winters, be they artificially
induced or simply the natural fluctuations of an interglacial period, are having
a noticeable effect on wildlife.  

On the moth front, yesterday and today I've had Spring Usher in the trap, a
species that only turns up here 1 year in 3.

John Murray,
Field End,                 j.b.murray at open.ac.uk
Marshalls Heath,
Wheathampstead,
Herts.,   U.K.