23.4.09

HAPPY THERIDION
GRALLATOR

Scientists have found themselves raising
a smile when studying this creature -
the happy face spider.

It has developed bizarre markings giving
the appearance of a smiling face.

The spider, Theridion grallator, which measures
just a few millimetres across is harmless to
humans. It has evolved the patterns
to confuse predators.

It is under threat of extinction in the
rainforests of the Hawaiian
island chain in the Pacific.


Dr Geoff Oxford, a spider expert from the
University of York, said: "I must admit
when I turned over the first leaf and
saw one it certainly brought
a smile to my face."


"There are various theories as to why the
spider has developed the markings it
has, one of these that it may be
to confuse predators."


"When a bird or other predator first sees
a prey item it has not seen before there
is a moment before it decides
whether to eat it or not."


"I don't think the smiling face is enough to
put off a bird though, but it would be nice
to think so. Not all happy-face spiders
have such striking markings, and some
are nearly all orange or all blue."


Dr Oxford, who has been studying the spiders
since 1993, said that the unusual markings
of the arachnid had made them a symbol
of all of Hawaii's threatened wildlife.


"They are ambassadors for all the
threatened invertebrates, insects
and spiders on Hawaii," he said.



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