A group of Kiwi researchers have
held a spider Olympics to get to the bottom of exactly how
much of a competitive advantage introduced false katipō
have over New Zealand’s native katipō.
The false
katipō are actually black cobweb spiders, originally from
South Africa.
Lead researcher James Roberts – who is
pursuing his conservation biology PhD from Sydney – told
Saturday Morning the false katipō appeared to be
more adventurous than its Kiwi counterpart.
“We had
the spiders traversing a maze, we had them climbing poles,
and running down a sprinting track while being chased with a
paint brush.”
The non-traditional “olympics” included
a series of tests common in spider research and showed a
possible frontrunner.
“They both climbed the pole with
the same speed and tenacity,” Roberts said.
“But it
seems as if because of the facts that the false katipō was
more exploratory and bold perhaps they can have some sort of
advantage in reinvading sand dunes that have been disturbed
by severe weather events or four-wheel driving or something
faster, allowing them to potentially out-compete the
katipō.”
The false katipō doesn’t bear the
distinctive orange stripe on its back as the native katipō
do, but the females are both black and shiny.
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The
males, the subject of the research, are about one sixth the
size of the females and are white with green and yellow
stripes.
Roberts said the fact the introduced katipō
were bolder was potentially associated with the invasive
biology.
“Invasive species have select advantages over
native species generally and that’s why they’re so
successfully invasive.
“The false katipō is worldwide
spread. It just seems to be doing really well at getting
into these new areas.”
Before comparing the spiders,
Roberts’ team needed to catch the katipō first.
That
was done relatively quickly according to Roberts whose team
worked with the Shorebirds Trust at Mangawhai’s Tara Iti
Golf Club to collect the two species at nearby Te Arai
Beach, where a healthy population of the spiders
thrive.
Asked whether there should be any concern
about the false katipō’s potential to invade, Roberts said
not in a physical sense.
“They’re not going to cause
you any harm invading your home or anything like that, and
they’re probably already there to be honest, but in the
sense for our native species, we don’t want to see them
being out-competed, especially by a South African
rival.
“So yes I think we should be concerned by that.
The katipō is a pretty awesome species and to see it
disappearing is pretty sad.”
Roberts said the
researchers could not yet say what effect the false katipō
was having on the native species so there was no suggestion
of culling the invaders.
Instead the focus was to look
after the sand dunes, which would help all kinds of
species.
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