Spiders.
Your reaction to that word might determine whether or not you finish reading this post, but try to bear with me — at least for a little while. While I can accept that most people aren’t nearly as fond of spiders as I am, I think all but the truly arachnophobic (it’s okay; I understand that you can’t help it) can agree that the jumping spiders are among the “cutest” and most acceptable spider groups. These active little hunters can often be found in or around the house, and their big binocular eyes and expressive “face” make them a lot more relatable than your average creepy-crawly. Well, most of them!
Jumping spiders, in the family Salticidae, are among the most well-researched spiders in the world, with over 6,500 species described. Meanwhile, the jumping spiders found in Aotearoa New Zealand – apart from the most commonly-encountered species – are very poorly known to science. There are thought to be around 200 species in NZ, with about 50 known well enough to be named. However, we can only reliably identify fewer than a dozen of them. Compare this with Australia, where hundreds of species are known already, and work to describe the rest is well under way.
Not to be outdone by the Aussies, Lincoln University’s Robin Long, along with her supervisor Dr Cor Vink, decided to do something about that. For her Master’s project, Robin set out to catalogue and describe the jumping spiders found in some of NZ’s most remote and extreme environments: the rocky heights of the South Island’s alpine zone.
Robin visited 21 different sites all over the Southern Alps, from Paparoa to Fiordland, collecting 170 jumping spider specimens (all by hand!) from up to 1,800 m above sea level — and logging some impressive hiking mileage in the process!
Through DNA analysis and careful examination of microscopic features on each spider, Robin separated those 170 specimens into 12 new species, and determined that the group was so unlike others known to science that it represented a brand new genus (a group of closely-related species with a common ancestor). She named this genus Ourea because, like the ancient Greek mountain gods, many of the species were found to be associated with a specific mountain range.
Many of NZ’s indigenous species are only found across quite small areas, often because of the (relatively) recent and rapid growth of our mountains — which even today continue to grow taller by around 7 mm per year. Formerly widespread species were split into separate populations by the tectonic uplift, and over the last few million years these now-isolated populations have diverged into new species. Robin’s jumping spiders, much like many other NZ alpine species, took advantage of the ample prey and new habitats created by the growth of these mountain ranges. Over time these spiders even developed cryptic colours and patterns that help to camouflage them against the particular rock types they live amongst.
Not content with merely describing a whole genus and a dozen new species, Robin also set about studying and describing the spiders’ behaviours when interacting with other members of the same species. Jumping spiders have exceptional eyesight, and are known for communicating with each other through visual displays that range from the bronze hopper’s simple leg-waving, all the way to the flamboyant, colourful dances (which often incorporate vibration as well) performed by the aptly-named peacock spiders.
The four Ourea species that Robin observed in the lab each exhibited a unique set of behaviours when they met another spider, and these behaviours differed depending upon whether they met a member of the same or the opposite sex. Males postured fiercely at each other, squaring up in a face-to-face grappling contest with legs and fangs outstretched.
When attempting to impress a female, males gestured with their legs and “zigzag-danced” their way closer, before attempting to reach out and gently stroke the female’s head. Perhaps unsurprisingly, this final move had quite mixed success! Females meeting each other were a bit more sensible, and usually made a few simple (though probably quite impolite) leg gestures at each other, before one or both turned away and went in the opposite direction.
Despite the enormous amount of work that went into researching these spiders, Robin acknowledges that her almost 150-page thesis has only scratched the surface of the topic. Little is known of the spiders’ life histories or the individual species’ spatial distributions, and it’s “very likely” that there are additional species in the genus waiting to be discovered on other mountain ranges.
Robin also suggests a similar study would likely uncover another distantly-related group of undescribed jumping spiders living quietly in the Southern Alps. This is a common problem with New Zealand’s invertebrate fauna: while we have a good general understanding of what’s around us, there are still huge gaps in our knowledge — and usually the studies that attempt to address this just end up revealing more unanswered questions!
We have a rich history of brilliant people, like Robin, studying, documenting, and describing New Zealand’s unique invertebrate biodiversity, and there are still many new discoveries to be made in every corner of our little country. But, despite huge technological advances, research has dwindled in recent decades due to funding redirections and the restructuring of government services.
Under the looming threats of climate change and habitat loss, we need to pay closer attention to the smallest and most enigmatic (if not always particularly cute) creatures that live alongside us, lest they disappear before we even have a chance to study them. Australia is well ahead of NZ in this regard, with funding and support for taxonomic studies provided through their world-leading ABRS scheme. I’m not much of a sports enjoyer, but beating the Aussies at this game is one trans-Tasman rivalry I could definitely get behind.
This article was prepared by Bachelor of Science (Honours) student Dustin la Mont as part of the ECOL608 Research Methods in Ecology course.
