First
record of orb weaver spider in London
January
2013. A large, rare spider has been recorded for the first time in London -
deep in tombs at Highgate Cemetery.
As
part of the Wild London Inclusive London project, staff at London
Wildlife Trust have been working with the staff and local community of
Highgate Cemetery since last summer. During a bat survey in December, Trust
staff came across a population of large spiders in the vaults of the Egyptian
Avenue at the Cemetery.
Britain's
largest orb weavers
Interestingly, these orb weavers are the species Meta bourneti, the rarer
of two species of Meta (Britain's largest orb weavers). The identity
of the spider was confirmed by Edward Milner, Spider Recorder at the London
Natural History Society - and it is the very first record of the species in
London!
Meta
bourneti is particularly fascinating because, due to its origins as a
cave-dweller (also known as a cave spider), it requires total darkness. Even an
outdoor night time environment is too bright for it, so the spiders never leave
the tombs.
A
sealed vault provides a perfect breeding ground. Most of these vaults - walk-in
tombs designed to house around four coffins - have not been opened for several
years. And, because the structures date from the late 1830s, it's quite
possible the spiders discovered have lived in the tombs for at least 150 years
without being detected. Meta spiders are amongst the largest spiders found in
Britain. They prey on small insects and woodlice. The females produce
teardrop-shaped eggsacs, which hang suspended on a silk thread from the roof of
their dwelling. When the spiderlings first emerge they are attracted to light,
unlike the adults which are strongly repelled by light. This helps the
spiderlings find new areas to colonise. Meta bourneti also need constant
temperatures and high levels of humidity. Elsewhere in the UK, these spiders
can be found in sewers, old cellars and abandoned railway tunnels.
Undisturbed
for 150 years
A sealed vault, on the other hand, provides a perfect breeding ground. Most of
these vaults - walk-in tombs designed to house around four coffins - have not
been opened for several years. And, because the structures date from the late 1830s,
it's quite possible the spiders discovered have lived in the tombs for at least
150 years without being detected!
30mm
in diameter
The find is made even more exciting by the spider's large size. Most new spider
records are for tiny species, but Meta bourneti measures over 30mm in diameter
with leg-span included.
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