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2009 was an important year for the Silver-spotted Skipper, with an exhaustive national
survey performed by Exeter University of all sites with suitable habitat in southern England.
This built on similar surveys in 1982 and 2000. Comparing the surveys in 2000 and 2009, and
boosted by reports from UTB members, we can conclude that:
The main string of sites is still healthy (Swyncombe Downs, Watlington Hill, Shirburn Hill,
all suitable parts of Aston Rowant NNR).
North-east of Aston Rowant, there are two reasonably strong colonies, with vagrants or
ephemeral colonies at many other sites between Aston Rowant and Beacon Hill.
There has been a retraction of the north-eastern range from Coombe Hill and Bacombe
Hill/Warren in 2000 to a northern limit at Beacon Hill (Ellesborough) in 2009.
Four new (or newly discovered) colonies were found in 2009.
The fringe colonies at Hartslock, Turville and other sites distant from the main
string along the scarp of the Chilterns appear to have died out.
The colonies on the Berkshire Downs have become progressively weaker.
Provisional findings: 7 colonizations and 16 local extinctions in the Chilterns,
between 2000 and 2009.
The previously reported expansion of range appears to
have reversed in the last 10 years or so, although the core sites are as strong as ever,
and are possibly consolidating. The widely-held view of the Silver-spotted Skipper as
a “success species” may therefore have to be revised.
Note the diagnostic colouring of the antennae in
the photos below: the male (left) has orange on the forward side of the tip of the
antenna, whereas the female’s (right) is plain grey - a useful aid in distinguishing the sex
when they sit with wings closed.
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Silver-spotted Skipper (male)
Photo © Richard Soulsby |
Silver-spotted Skipper (female)
Photo © Richard Soulsby |
Thanks go to everyone who sent reports of sightings by
email, website or as Levana records, and to those who performed and helped with the
comprehensive survey in the Chilterns.
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