Many butterflies, both in the tropics and in temperate regions hide
under leaves in overcast or rainy weather and roost beneath them at
night. They are often patterned and coloured in such a way as to
minimise detection by avian or mammalian predators at these times.
Brimstone Gonepteryx rhamni for example
is wonderfully camouflaged as it hangs beneath leaves of dogwood,
buckthorn, bramble or ivy. Its wings are very leaf-like in shape and
colour, and even have raised venation to simulate the veins of real
Brimstone Gonepteryx rhamni
at roost beneath a
dogwood, Hampshire, England ©
Pyrgines such as the
Grizzled Skipper Pyrgus malvae
usually roost at the top of dead flower-heads. The Dingy Skipper
Erynnis tages behaves similarly, but
takes things a stage further by wrapping it's wings tightly around
dead knapweed flowers, where it is almost impossible to see ( unless
you are a very determined entomologist ! ).
roosting on a dead
knapweed flower, Hampshire, England ©
Polyommatine Blues usually roost at the top of
grass heads, assuming a head-downwards posture. Satyrines such as
Small Heath, Marbled White and Meadow Brown commonly roost on grass
heads or flower heads. Checkerspots and Pearl-bordered Fritillaries
adopt a similar tactic, often roosting on the flowers of rushes.
Such strategies may seem a little difficult to understand, as the
butterflies are easily spotted. The probable explanation is that
they are choosing sites where they are out of reach of nocturnal
predators such as mice.