All content, information and images provided in this presentation are Perth Zoo.

The Socially Responsible

Science Writing Conference

The Western Swamp Tortoise as a learning context

Presented by: Wayne WaltersPerth Zoo Education Officer

Photo: D Scarparolo 2007

Overview• The Western Swamp Tortoise is the most

critically endangered reptile in Australia.• It was thought to be extinct for over 100 years

and was rediscovered by chance in 1953.

Western Swamp Tortoise, Pseudemydura umbrina

Photo: G Scales

Threatening Processes• Habitat loss

• Introduced species

• Climate change

• Intra-specific factors

Photo: G KuchlingEnvironmental Protection (Western Swamp Tortoise Habitat) Policy 2002

Habitat Loss• Only found in two small areas of natural habitat in the Swan Valley.

• Why has there been a loss of habitat?

- Draining and/or filling of wetlands on the Swan Coastal Plain for agriculture, industry and urban use.- Modified catchment process because of urban drainage modifications.- Pollution from vehicles entering the catchment via stormwater run-off.- Impact of summer bushfires.

Habitat Loss: Discussion Points• Why did urban planners fail to see any value in preserving the wetlands on the Swan Coastal Plain?

• Why are wetlands important?

• What can be done to stop the rate of habitat loss for the Western Swamp Tortoise and to improve the

quality of their currently degraded environment?

• How can we create a balance between preserving a critically endangered species and a growing human population?

Introduced Predators

• Feral predators such as cats, foxes and rats prey on tortoises and their eggs.

• Fox control has involved baiting programs and ‘fox-proof’ fencing. Photo Courtesy: DEC

Introduced Predators: Discussion Points

• Domestic cats accompany the urban encroachment around the remaining Western Swamp Tortoise habitat.

• What could be done by pet owners and the City of Swan to reduce the impact of these animals on native animals such as the Western Swamp Tortoise?

Photo Courtesy: DEC

Climate Change• Reduced rainfall levels means that the wetlands

are not filling up to the same extent as in the past.• This increase in aridity reduces the quality of the

remaining habitat and the availability of food.• These changes may affect the environmental

cues and natural biological rhythms of the Western Swamp Tortoise.

Climate Change: Discussion Points• Climate change is a term that is currently everywhere in the

media, but what does it really mean?• What are some of the implications of climate change for:

- Natural biodiversity

- Agriculture

- Fisheries

- Our lifestyle• What actions can YOU take to help combat climate change?

Intra-specific Factors• Limited biogeographical range (only found on the

Swan Coastal Plain).• Low fecundity (reproductive rate) and slow growth

rate.• Aestivation – when swamps are dry, Western

Swamp Tortoise aestivate (a type of summer hibernation) in holes in the ground or under deep leaf litter).

Captive Breeding• Perth Zoo’s Native Species Breeding

Program (NSBP) has been breeding Western Swamp Tortoises since 1990s.

• Over 400 tortoises have been successfully reared at Perth Zoo.

Photo: D Scarparolo 2007

Captive Breeding: Discussion Points• Unless additional habitats are found and

protected, and the captive breeding program continues, this species will never survive outside these two special reserves. Is there any point in saving this animal when it appears to be on the downward spiral to extinction?

Useful WebsitesPerth Zoo

www.perthzoo.wa.gov.au

Department of Environment and Conservation

www.naturebase.net

Department of the Environment and Water Resources

www.environment.gov.au/biodiversity/threatened/publications/wa2003.html

Friends of the Western Swamp Tortoise

www.westernswamptortoise.com

Thank you for your attention.