Nelson Nature Fix

16 April 2019

After a break over the summer, welcome to the first 2019 Nelson Nature Fix - a regular snippet about Nelson's natural environment, and what we can do to look after it.  If you know anyone who you think might enjoy getting a regular nature fix, please pass this on and encourage them to sign up. You can read back issues here.
 

Along came a spider.....

The infamous katipo (Latrodectus katipo) spider is an endangered native species and one of our threatened coastal species. It is estimated that there are only a few thousand katipo left making it rarer than some species of kiwi.  

This species is at risk of extinction and is in decline throughout NZ. In 2002, there were only 26 populations known in the whole of New Zealand, including a couple of sites in the Nelson region.
 
The main factors contributing to its decline are loss of habitat and declining quality of the remaining habitat. Katipo live among sand dunes, much of which has been modified for farming or urban development. Invasive plants like marram have also led to the decline of suitable habitat.
 
The name katipo is from the Māori katipō, meaning "night-stinger". It is a small to medium-sized spider, with the female having a round black or brown pea-sized body. Red katipo females, found in the South Island and the lower half of the North Island, are always black, and their abdomen has a distinctive red stripe bordered in white.
 
Webs are typically established in low-growing dune plants and other vegetation such as the native pingao or driftwood. Katipo feed mainly on ground-dwelling insects, caught in an irregular tangled web spun amongst dune plants or other debris.
 
Katipo need fairly specific habitat to build their webs. Native pingao typically grows with bare patches of sand between the plants, leaving space for the spiders’ webs. Plants like marram, an invasive grass which was originally planted to stabilise dunes but is now considered a weed, grow in denser stands which make it difficult for the katipo to construct a web able to catch their insect prey.
 
Although they have a fearsome reputation, katipo bites are very rare. No deaths have been reported since 1901 and the most recent reported bites were to a Canadian tourist in 2010 and a kayaker in 2012. Bites are rare as the katipo is a shy, non-aggressive spider. The katipo will only bite as a last resort; if threatened the spider will usually fold up into a ball and drop to the ground or retreat to the nearest cover. They are more scared of you than you are of them!
 
What is Nelson Nature doing to help katipo? Helping to conserve precious dune habitat in Nelson, by protecting against weed invasion and by restoration planting.
 
What can you do to help katipo? Keep to marked trails in the dunes, get involved in dune restoration projects and don’t collect driftwood.
 
Keep yourself and the katipo safe by giving your clothes a good shake if you’ve left them lying on driftwood.