When I was invited by Conservation International to participate in
one of their biodiversity surveys in Papua New Guinea, I knew a
decades-long dream was about to come true. New Guinea has a special
appeal for those of us studying jumping spiders, because it's home to
some unique species, including the strange long-legged Diolenius and the
isolated Cocalodes. I had never seen either of these alive in the field,
and I was excited about the chance to do so. I was also hopeful about
encountering some species new to science. Few researchers have spent
time in the jungles in this area collecting, and I thought there was a
good chance I would see some spiders no scientist had ever seen before.
Our Conservation International team of biologists included scientists
who study mammals, birds, plants, amphibians, reptiles, and myself (1 -
I'm third from left). Our goal was to survey the rich biodiversity of
one of Papua New Guinea’s largest undeveloped highland wilderness areas,
in the hopes that this information could be used to develop a
conservation management plan to protect this large area of undeveloped
forest.
The areas we were attempting to survey were very remote. After a series
of flights in successively smaller planes, a helicopter dropped us off
at a field camp in the mountainous land of the Hewa people (2). All
supplies had to be helicoptered in, and we often had to walk for hours
before we reached the particular patch of forest where we planned to sample.
Each team member collected his organisms in his own way. Each
morning I'd go out into the forest with carpenter's pouches full of
small glass vials. If I saw a spider on the ground, or a tree trunk,
I'd convince it to go into a vial, pop on the lid, and then continue
on. A special method that works well for jumping spiders is to hold
a sheet stretched with sticks (like a kite) under a bush and shake
the bush. Spiders that fall onto sheet can easily be chased into
vials.
When I set off to Papua New Guinea, I was really hoping that I would
find a specimen of Cocalodes (3). This spider has not been studied much, but
it has a number of unusual features that we think may give us clues about
what the earliest jumping spiders were like. I went to Papua New
Guinea in large part to get fresh specimens of Cocalodes for a more
in-depth study.
I got Cocalodes all right (what a thrill to see it alive!), but what
else I got astonished me. I found three genera related to Cocalodes that
are new to science. The names I gave them - Cucudeta (4), Tabuina (5)
and Yamangalea (6) - are all taken from the words for "spider" in the
local languages, of which there are many in New Guinea. Cucudeta, I must
admit, was my favourite. It's a little spider hiding in leaf litter in
mountain rainforests (7), looking a bit like an ant.
Finding new species is always exciting, but these spiders are
particularly exciting because they radically changed our ideas of how
this group of spiders evolved. Before this trip, we thought that
Cocalodes and its "sister" Allococalodes were alone on their isolated
branch of the evolutionary tree. Instead, we discovered that they
aren't alone, but are accompanied by these three new genera. One of
them, Cucudeta, with its tiny antlike body, is strikingly unlike
Cocalodes. It seems that Cocalodes has many more relatives than
we had thought. Since returning to the lab, we've been able to
gather some genetic data, and our preliminary analyses confirm that
they are indeed outside the main radiation of jumping spiders.
I found many other species of jumping spiders, including many others new
to science (8). It will take some years before we are able to study them
all. And these are the results from just one expedition to a few sites
in one island. Many other new species remain to be found in New Guinea,
Borneo, the Amazon, and around the world. I only wonder how many we will
find before they go extinct....
