Canterbury's red and blacks on the decline!

The infamous red and black spider, the katipo, is becoming a rarer inhabitant on our beaches.

The katipo spider is endemic to New Zealand. They have a large shiny black globular abdomen, with an orange or red strip down the centre. They span little more than 25 mm. The female body length is about 6mm, while the male is smaller, usually about 4mm long. The male spider has white marks on his sides in addition to the red strip. Live katipo spiders are on display at the Discovery Centre in the Canterbury Museum.

Katipo spiders are found mostly north of Banks Peninsula. They have a preference for sandy, sloping coastal habitats with sparse marram or pingao grass in which they weave small tangled webs to catch insects. Although they also like to live in driftwood, little driftwood remains undisturbed on our beaches for long enough.

James Griffiths, a student at Lincoln University, is studying the lives and habitats of the katipo spider. Studies show a decline in numbers over much of New Zealand. The reason for this decline is probably due to the katipo spiders’ slow ability to recover from a loss or disturbance of their habitat. An introduced South African spider, Steatoda capensis, may be displacing the katipo spider, as it is better at recolonising newly vacant sites. Compared with S. capensis, the katipo is not such a fast reproducer, and it is only available for recolonisation from a small habitat area.

It is likely that the katipo will continue to decrease in numbers as their habitat is continually  disturbed by human interference along coastal areas, and from storm events. So help keep the red and blacks on the Christchurch coast line! It is important to not disturb them. To achieve this, we can do the following:

• keep to the marked tracks through the sand dunes
• protect our native dune vegetation
• encourage the growth of pingao
• leave driftwood undisturbed

Are you a spidery type of person or want to become one? You can help James with his study to keep the red and blacks on our shores! Email James: (griffith@tui.lincoln.ac.nz) or contact Coast Care

If you can help us grow pingao grass, contact Coast Care for a pingao growing kit, phone (03) 382 1678.