Snakes Harmful and HarmlessTM



On the Captive Breeding of an Analogue for both Australia's most Endangered Python, the South-western Woma ('Aspidites ramsayi') & Pilbara Olive Python (Liasis olivaceus barroni)


Prepared in 1997 by the

Western Australian Society of Amateur Herpetologists Inc.

for the Executive Director, Department of Conservation and Land Management, 50 Hayman Road, COMO WA 6152 Australia


Introduction

This submission precedes applications by private herpetologists to keep the species concerned. The primary objective of which is to initiate the acquisition of wild Womas (Aspidites ramsayi) and Pilbara Olive Pythons (Liasis olivaceus barroni) for captive breeding purposes. We highlight the need to establish these two species in captivity and improve their conservation status. Both taxa have for some time now been listed on various schedules under the Wildlife Conservation Act 1950 as fauna in need of special protection. They appear in the Australian Reptile Action Plan (Cogger et al., l993) where the south-western woma ranks as Australia's most endangered python. The Australian Nature Conservation Agency (ANCA) has recently included it on the Australian and New Zealand Environment and Conservation Council (ANZECC) List of Endangered Vertebrate Fauna. Despite this, our knowledge of both in WA is almost nil. The endangered status of the south-western woma is exacerbated in Western Australia by the lack of formal recognition of its probable divergence. Without immediate investigation the taxonomic status of this animal may never be known.

Here we follow Smith (1981) and recognise the south-western woma as occurring from Yuna south to Boddington and east to Karalee and near Menzies. We consider both the Shark Bay (Peron Peninsula) and Nullarbor populations to be more typical of the northern and eastern populations.

The Species Concerned

Woma (Aspidites ramsayi):

Several authors have documented the severely threatened status of the south-western woma (Smith, 1981; Cogger et al., 1993; Ehmann, 1992; Pearson, 1993). To our knowledge no published information is available on it and no individuals are in captivity. Several herpetologists have remarked on the morphological and colour differences between this population and others (Barker & Barker, 1994). As we presume it to be geographically isolated, it is imperative that its taxonomy be established. We fully agree with the Barkers' recommendation that CALM consider an unprecedented arrangement with herpetoculturists to establish a captive population. Because of the apparent rarity of the south-west form we do not foresee this happening with this population in the short term. Although to develop the skills needed we suggest the immediate recruitment of Pilbara individuals as analogues. In short, we know nothing about the south-western form except that it has declined in numbers dramatically. Establishing Western Australian womas in captivity for study will allow us to make a significant contribution to the knowledge-base of this species. All available data to date is from populations outside Western Australia.

Pilbara Olive Python (Liasis olivaceus barroni):

Apart from the original description of this subspecies by Smith (1981), little data is available on it. Mr Klaas Gaikhorst of the Armadale Reptile Centre has the only two held in captivity. Barker & Barker (1994) provide brief notes on its colour, scale morphology, size, distribution, habitat and food. There is nothing on sex determination, breeding, eggs and hatchlings in the literature. We fully agree with the Barkers' recommendations for this subspecies also. The Pilbara region is becoming increasingly more open to mining and tourism. Large bodies of water appear to be an integral part of this python's ecology. The demands on these for human use, both as a resource and for recreation, may result in progressively more negative pressure on its continued existence. We believe that it is now timely and crucial to establish it in captivity. This is a cost effective way to acquire data and contribute to its conservation. David Pearson, CALM researcher, has recently begun radio-telemetry studies on this python to gather information on its ecology. Our proposal will complement his work by providing the types of data listed on Page 4. This information is difficult to obtain during field studies.

Source Of Original Stock & Numbers Required

A minimum of three pairs would be required to optimise the success of this project. Multiple pairs would both substantially increase the chances of breeding them and maintain the genetic health of the captive population. This would also spread the work-load around allowing us to develop adequate husbandry techniques. As there are no captive sources available (apart from K. Gaikhorst's two male L. o. barroni) all will need to come from the wild. WASAH members in the Pilbara are occasionally called in to remove individuals of both species in towns. These could be sourced for our purposes.

Priority One: The South-Western Woma

The most recent records of the woma in the wheatbelt, based on size, have been of old adults. This is of considerable concern to us. Maybe recruitment into the population through reproduction is negated by predation. Most sightings suggest a close association with banksia on deep sand where rabbit warrens occur. Rabbits may have replaced native mammals as food for this python. The removal of which will both reduce its food resources and increase the threat from exotic predators. The eventual increase in numbers through captive breeding will allow a buffer for any unforeseen problems, especially if rabbit numbers decline rapidly as a result of the calicivirus. There is an urgency to locate individuals for radio tracking so that we may determine its ecology. This will lead to the identification of specific areas needed to be reserved to protect extant populations.

There is less urgency concerning the Pilbara olive python but nevertheless a captive breeding program should be in place. David Pearson has already implemented radio tracking of this subspecies.

Disposal Of Progeny

Offspring to be distributed to interested private herpetologists and institutions. To ensure genetic diversity a stud book would be produced. With proper support and management by species supervisors we cannot foresee any problems. Surplus stock would go to the Western Australian Museum and other interested scientific institutions for biochemical and chromosomal analysis, etc. The introduction of suitably aged excess stock back into the wild will be assessed later. If this occurs then their progress can be monitored with transmitters. This will depend on available resources. It would be unwise to release young back into areas rampant with foxes and cats until the impact of predation by feral animals is assessed.

Costs?

Private herpetologists can assist in the monitoring of radio-fitted snakes, captive breeding and associated data recording. The costs involved here would be almost nil. We have at least six to eight interested people who are motivated, self-funded and ready to go. With no financial support WASAH, targeting the south-western woma, has been conducting a public awareness program, correlating reported sightings and involved in attempts to locate individuals. The south-western woma does need help immediately and captive breeding of an analogue will play a major role in the continued conservation of it. Cogger, et al. (1993) estimate the cost to set up a specific breeding program to be $16,000. Here is a saving immediately: WASAH will set it up for nothing. The Pilbara olive python project will similarly result in further savings.

What Will We Learn?

Following is a brief outline on the data that will result from captive breeding. This list is inexhaustible. The results of any studies by WASAH members would be published in an appropriate journal or newsletter such as the WASAH Newsletter, Western Australian Naturalist, Herpetofauna, Monitor, Hawkesbury Herpetologist, Records of Western Australian Museum, etc.

An analysis of various husbandry techniques will establish:

1) optimum husbandry requirements concerning caging, heating, substrates, diet, etc.

2) Sex determination/dimorphism.

3) Sloughing frequencies and growth rates of adults & siblings.

4) Eggs and incubation, including both artificial and maternal brooding and temperature.

5) Neonatal size and any scale anomalies at birth.

6) Ontogenetic colour change and its relationship to thermoregulation and anti-predation.

7) Reproductive behaviour.

8) Male/female and male/male interaction.

9) Ovulation cycles.

10) Fecundity.

Recommendations

1. That CALM concur with the Cogger, et al. (1993) and ANCA in recognising the South-western Woma as distinct and elevate this population to Schedule 1 as fauna that is rare or likely to become extinct.

2. That CALM recognises the urgency of this proposal to improve the conservation status of the South-western woma. As it is one of the world's rarest pythons, WASAH will continue with searches, public awareness and communications with CALM in this regard.

3. That CALM license private herpetologists (WASAH members) for one or both species.

4. That CALM recognises the positive contributions made by private herpetologists in Australia and endorse the recommendations of the Australian Reptile Action Plan and make this proposal a reality. This is in line with CALM Policy Statement 29, which proposes the captive breeding of threatened species and the involvement of other organisations in this.

The greatest accomplishment of keeping any threatened animal in captivity is to breed it and, in so doing, collect data on the species concerned. There are several success stories regarding this in poorly known or rare reptiles in Australia. Less than a decade ago in Victoria only three individuals of the Collett's Snake (Pseudechis colletti) were kept by private herpetologists. Now, after captive breeding, it is one of the most common snakes in captivity, however Ehmann (1992) lists it as sparse in the wild. We anticipate the success of this Western Australian proposal to parallel that of Collett's Snake. The result would be both a massive increase in our current knowledge of these species and a sustainable captive population of the south-western woma and Pilbara olive python. There is plenty of interest within our society for this project to become a reality, all it needs is the support of CALM.

Signed by Brian Bush on behalf of the Executive and members of WASAH. Address all correspondence regarding this proposal to 9 Birch Place Stoneville WA 6081.

References

Barker, D.G. and T.M. Barker, 1994. Pythons of the World. Volume 1, Australia. Advanced Vivarium Systems, Inc. 171pp.

Cogger, H.G., E. Cameron, R. Sadlier, and P. Eggler, 1993. The Action Plan for Australian reptiles. Australian Nature Conservation Agency. Australian Museum, Sydney. 254pp.

Ehmann, H., 1992. The Encyclopedia of Australian animals, Reptiles. Angus and Robertson. 495pp.

Pearson, D., 1993. Distribution, status and conservation of pythons in Western Australia. In Herpetology in Australia, a Diverse Discipline. Ed. Lunney, D., and D. Ayers. Transactions of the Royal Zoological Society of New South Wales. Surrey Beatty and Sons, Sydney. 383-395.

Smith, L.A., 1981. A revision of the python genera Aspidites and Python (Serpentes: Boidae) in Western Australia. Rec. West. Aust. Mus. 9 (2): 211-226.


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