TWO LEGS OR EIGHT? WHICH COMES FIRST, MAN OR SPIDER?

Philip G. Wood, Buller Caving Club

Introduction

In 1968 when logging roads were being extended to what is now the Oparara Arch carpark, a group of venturers accompanied by myself together with a forestry officer, Mr Brian Denton, did some preliminary exploration of the limestone area in the Oparara valley. During this period eight caves were found and explored. These caves were registered with the NZSS in 1973. We named two of these caves Box Canyon and Crazy Pavement.

Crazy Pavement Cave is accessible from Karamea, 12km along the Heaphy Track road and 18km along a bush road, about an hours journey. The topography, geology and climate of the area is described in 'Limestone Arches of the Oparara River' (Wood and O'Shea, 1983).

Box Canyon is a large enclosed canyon with fossil shells in the roof. Crazy Pavement is a walk-in cave with a large mudcrack floor and is the home of spiders and cave wetas. I consider this to be a scientific cave and the Box Canyon an any person cave. Why? Because Crazy Pavement has the largest collection of a special species of spider that I had found in one area in the Oparara, in over seventy caves discovered.

These spiders represent the last survivors of a kind which flourished hundreds of millions of years ago and to the student of spiders their discovery creates the same interest which the Tuatara raises amongst the specialist in reptiles. These four-lunged true spiders which are found in Brisbane, Australia and Southland, New Zealand, hunt their prey on the forest floor, and have been named as a new genera called Gradungulidae.

The most surprising chapter to the story of these spiders was begun with the discovery, a few years ago by some enthusiastic speleologists, that further members of the species live deep in the darkness of some caves in the South Island. This cave spider, which was unnamed until 1987, has developed long and spindly legs; the body of the spider is a moderate inch (2.54cm) in length and its legs as they move may span a full five inches (12.7cm) making this the largest known spider in New Zealand.

At the time the cave spider was not considered common, being known only from two caves in the South Island (Ida Cave, Oparara 1957 and Motupipi Cave, Takaka 1958). It is not known precisely what is caught for food, but they most probably prey on cave wetas which abound on the walls of the caves they inhabit. The eggs, laid in November, are enclosed in a 2.54cm (average) long, white egg sac shaped like a pear which hangs from the walls by a slender stem. Apart from this fact, as far as I am aware, nothing is known of the life-cycle of this fascinating and scientifically important group.

In February 1983, I supplied an arachnologist Raymond Forster, with the holotype male Gradungulidae spider from Wonder Sump Cave, Oparara. The spider was named Spelungula cavernicola. The generic name is based on the Latin spelunca (cave) and is feminine in gender. Distribution is confined to caves in the Nelson district of the South Island of New Zealand.

We still need to know - are there enough in the area to survive? Why the difference in their colouring? Do they re-use their egg sacs? How often do they make a new egg sac? Is food supply sufficient? Are they the same in both the Karamea and Takaka areas? We need observations on the capture of prey by these spiders in the wild. How long do they live? How long do the eggs take to reach maturity? what is the distribution of these spiders? Last year I found one 2.5m up a tree!

Questions

  1. When is a scientific cave a tourist cave?
  2. How much research do you have to do before you develop public access to a cave with scientific values on which not enough is known about its inhabitants?

History of Development

The area was under the control of the New Zealand Forestry up to 1987 and was taken over by the Department of Conservation. With reference to Crazy Pavement Cave I wrote:

  1. letter to New Zealand Forest Service 11.7.84
  2. letter to Department of Conservation 5.4.88
  3. letter to Department of Conservation 10.1.89

Because of cave modification done in 1988 for 'two legged invaders' scientific information of some importance may be lost because the Crazy Pavement Cave has been opened to visitors too soon.

Summary Remarks

Caves of scientific interest should not have public access provided until they have been thoroughly researched.

More work on the spiders in the Oparara caves is necessary.

Discussion

What management policies should be adopted?

What is the management process in this situation?

Acknowledgments

Information from the Director of Otago Museum, Raymond R. Forster, in the form of letters is hereby acknowledged.

References

Wood, P. and O'Shea M. (1981). Limestone Arches of the Oparara River. NZSS Bulletin No.127 Vol. 7

Forster R.R., Platnick, N.I. and Gray M.R.(1987); A Review of the spider Superfamilies Hypochiloidea and Austrochiloidea (Araneae, Araneomorphae). Bulletin of the American Museum of Natural History, Vol. 185, New York.

Personal Communications.

Forster, R.R. Private Letters dated 25.02.1983, 26.04.1983, 12.05.1983, 27.06.1983


11.7.84

Westport.

N.Z. Forest Service
NELSON.

Re Cave "CRAZY PAVEMENT" No.A.R.106 OPARARA


Suggested scientific reference cave for the Gradungula spider.

On the 21.4.84, I tagged and listed the following in the cave:

11 Gradungula spiders
20 Blank egg sacs
some on the floor not counted
3 New egg sacs
No.7441" spiderblank egg sacs20 total
No.8491" spider  
No.8753" spider female  
No.7493" spidernew egg sacsNo.741
No.8705" spider No.734
No.8943.5" spider No.893
No.8845" spider female    
No.8632.5" spider  
No.8853" spider  
No.3712" spider  
No.8913" spider  
Total 11   

This is handy to a track and can be monitored.
Enclosed is a sample of tags.
This is the largest collection of these spiders in one area in the Oparara I have found.

Yours faithfully

Philip Wood.


5th April 1988

Westport

Dept. of Conservation
WESTPORT and KARAMEA.

Re cave "CRAZY PAVEMENT" No.A.R.106 Oparara Basin.

On the 21st of April 1984 I tagged and listed in this cave the following 11 Gradungula spiders and 23 egg sacs made up of spiders of from 1 inch to 5 inch (visual sizing), 20 blank egg sacs and three new sacs; total 23. As this was the largest collection of these spiders in one area in the Oparara I had noticed, I suggested that that it should be a scientific reference cave for the Gradungula spider.

New public access developments have just been introduced to this cave under new management and to update the previous information on the 4th April 1988 I again looked at the position of this now described new species of spider Spelungula cavernicola.

3" spider (light colour)     All egg sacs
5" spiderincluding on floor.
5" spider33 in total.
5" spider 
2.5" spider (light colour)   
2" spider 
2" spider 
3.5" spider 
2" spider 
2" spider 
4" spider 
3" spider (light colour)   
3" spider 
Total 13 spiders 

Yours faithfully

Philip Wood.

 

198421141-2-11
1988-413113-13

23 Romilly St
Westport
10th Jan.1989.

Dept of Conservation
WESTPORT and KARAMEA.

Re spiders in cave "CRAZY PAVEMENT" A.R.106 Oparara Basin.

On the 3rd of Jan 1989 I revisited the above cave and did another survey of the spider population. My first impressions were that there were not many but in doing the survey noted that 95% were light in colour. Normally they are dark in colour.

Report on egg sacs: Total 33 including 10 on floor. I did not inspect the egg sacs.

Report on the Spelungula cavernicola spider.

From back of cave to front:

2" spider
4" spider
2" spider
4.5" spider
3.5" spider
1.5" spider
2" spider
3" spider
2" spider
Total 9 spiders.

Yours faithfully

Philip Wood.

Comment:

The size range 1" and 5" are missing.
A 4.5" spider was seen outside on the 1.1.89;
7ft up a tree in the Upper Oparara.
The population is down.
Food supply was plentiful (weta).

size1.522.533.544.55inches
198421141--2total 11
1988-41311-3total 13
198914-1111-total 09

Editor's Note.

Spelungula cavernicola is now known from a number of cave sites in the Oparara, including Honeycomb Hill Cave which is fully protected and subject to a comprehensive management plan.

Crazy Pavement cave was 'developed' with boardwalks primarily because of the value of the intact dried 'crazy paving'-like condition of the floor and because this floor was being damaged through use and at further risk. It is important to note that the cave is located a very short distance from the Oparara access road.

The 'development' was made only after careful consideration and consultation with the Buller Caving Group and the New Zealand Speleological Society. The cave was classified 'open' in terms of the national policy and guidelines for karst and caves.

A sign has been erected at the entrance of the cave asking users not to disturb or touch the spiders.

It is acknowledged, however, that further research is required into the life cycle, habitat requirements and distribution of Spelungula cavernicola. A research project was recommended in 1988 and will commence this financial year.