ON THE EDGE - Duke of Burgundy in the
Stour Valley
The Duke of Burgundy butterfly Hamearis lucina,
or ‘Mr Vernon’s Small Fritillary’ as it was once known, is without
doubt one of the rarest and most endangered butterflies in the British
Isles. Fortunately, this charming little butterfly still flies in a
handful of sites in Kent.
Often referred to as a fritillary but in spite of its
similarity to that family, it is in fact a ‘metalmark’ (Riodinidae).
Most of the 1200 or so species in the family are found in Tropical
America, the ‘Duke’ being the only representative of the Riodinidae
in Europe.
The species requires exacting habitat conditions, and
may be found breeding on Primula on rough calcareous grasslands and
in woodland clearings. Such sites are becoming scarce and even where they
do exist other critical factors, like grass sward height might not be
suitable. In fact you might wonder how this rare beauty still occurs.
However, despite the marked loss of suitable habitat and
the associated reduction in the butterflies range and population, there is
still hope. This gem of a butterfly has its friends and a number of
organisations have mobilised in an effort to turn the tide. At Denge Wood,
near Petham, Forest Enterprise, Kent Wildlife Trust, The Woodland Trust,
Butterfly Conservation and various private landowners are currently
undertaking habitat creation aimed at reversing its fortunes. A one
kilometre long ride connecting ‘Bonsai Bank’ and ‘The Warren’ has
been widened from just two metres to 30 metres to encourage the butterfly
to colonise new areas. As part of the work some trees have been left to
grow to maturity and much dead wood has been retained, so this newly
created green corridor will also benefit other wildlife. Further work
includes the ‘opening-up’ of a scrub covered chalky bank and a return
to coppicing in other areas. These scrubby grasslands, with their
increased light and warmth, will serve to encourage Primula,
particularly cowslips, the caterpillar’s preferred food plant.
Although occasionally encountered on the Crundale Downs,
Bonsai Bank is the most reliable site locally to watch this butterfly with
a couple of dozen on the wing at peak times. The flight season lasts four
to five weeks during spring and early summer, however individuals only
live for an average of five days! Therefore, views are never guaranteed
and several visits may be necessary, so dust off those hand-lenses and
GOOD LUCK.
Jason Mitchell, Canterbury & Lower Stour
Countryside Officer
Acknowledgements:
Peters, Steve 2004 Forest Enterprise
Kirby, Peter 2004 Butterfly Conservation
References:
Oates, M 2000 The Duke of Burgundy – conserving the
intractable. British Wildlife 11: 250-257
