Turtles

The City of Cockburn is home to a species of long neck turtle native to Western Australia. This turtle is known by many different names, you will find it in seasonal and permanent fresh water areas such as rivers and wetlands. The City is involved in research on the turtle to better understand its biology and how we can protect them.
Common Names
Common names for this species include: Southwestern Snake-Necked Turtle, Oblong Turtle and Long-Necked Turtle. The turtle owes its name to the oblong shape of their carapace (upper shell) and snake-like long neck. The three common names that it is referred to highlights the species unique and distinctive appearance.
Whadjuk Nyungar Names
The Whadjuk Nyungar names for this turtle are Yaakan and Booyi, which translate to long-necked turtle.
Scientific Names

This species has had a complicated taxonomic history.  For many years there has been confusion surrounding Chelodina colliei and the northern snake-necked turtle (Chelodina rugosa) since the two species were first recognised as separate species.  In 1889 the two species were mistakenly considered as one widespread species and this thought until 1967 when they were confirmed as two distinct species as originally suggested, with the southwestern turtle being C. oblonga. Then in 2013 this was changed giving the oblonga name to the northern turtle, with the southwestern turtle being called C. colliei. Testing confirmed that the holotype of C. oblonga is the southwestern turtle, but to avoid further confusion between the two species the International Commission on Zoological Nomenclature ruled that the southwestern turtle continue to be C. colliei and the northern to be C. rugosa, with C. oblonga rendered obsolete. However, a recent research article in 2020 argued for the sake of consistency with previous literatures and identifications that the original scientific name, C. oblonga be officially used.

Appearance and Habitat

Physical appearance and features
This species is known for its long and thick neck which extends as long as or longer than its carapace (upper shell). The carapace is between 20 to 30cm and is very oblong in shape (which is narrow and oval). The carapace is dark brown or black in colour while the plastron (bottom shell) is pale. The neck and shells of an adult turtle can reach up to 50cm in length. Hatchings have a carapace roughly the size of a 20 cent coin. Their forefeet have 4 claws each.
Turtle behaviour
These turtles are commonly found in waterways of the Perth metropolitan area throughout the south west, extending north to Hill River, inland to Toodyay, Pingelly and Katanning and east along to the south coast to the Fitzgerald River National Park. You can find these turtles in permanent and seasonal freshwater habitats including rivers, lakes, swamps, and natural and constructed wetlands. In the City of Cockburn these turtles are found in most of our wetlands.
Turtle behaviour
The annual nesting season for these turtles is between September to February. The females leave the water to lay their eggs on nearby land in sand or soil between September to March each year. They can lay up to 16 eggs. Females may travel long distance in search of suitable nesting sites. Hatchlings start breaking out of their eggshells to migrate to nearby waterways (lakes) anytime between March to August depending on weather conditions.

Their mainly carnivorous diet includes frogs, fish and macroinvertebrates (animals with no backbone) such as insects, crustaceans, snails and worms. Hatchlings may also eat aquatic plants and midge and mosquito larvae. This helps the natural ecosystem by controlling possible nuisance midge outbreaks.

These turtles have a long lifespan of over 40 years. They can drop their body temperature, slow their pulse rate and use stored body fat instead of eating to survive in hot dry conditions. Sometimes they bury themselves in mud or under leaves or logs, conserving body fluids until conditions are more habitable. This ability is known as aestivation. When this occurs, turtles can be more vulnerable to predators and human activity such as clearing and groundworks.
 

Threats

Threats such as habitat modification and destruction, predation, and wildlife-vehicle mortality are placing pressure on urban populations of the species, which appear to be declining. The City is working hard to help understand this species and safeguard its survival in our wetlands.
Predation and poaching

As turtles travel up to 1km to lay eggs away from waterways, this makes them a vulnerable species to motor vehicle accidents and predation by animals. Many are hit by motor vehicles and killed when crossing nearby roads. Turtles have a high mortality rate due to predation by Ravens, birds, dogs, cats and foxes. Feral animals are a significant threat to this turtle, especially by foxes which attack them and their nests. Because foxes are an introduced species to the region, the turtle has not developed sufficient defences against it. Additionally, turtle poaching for pets is illegal but still a threat. These threats play heavy roles in decreasing hatching survival and turtle population.

Habitat loss and poor water quality

Increased development around wetland areas leads to disjointed and reduced habitat for turtles. Urbanised wetlands in metropolitan areas also contain high nutrient levels (nitrogen and phosphorus) and heavy metals such as magnesium, mercury and copper which affect water quality. Turtles may ingest, inhale and absorb polluted water. Turtle shells that are heavily covered in algae suggest high nutrient levels in the water.

Turtle conservation efforts by the City

The City is dedicated to conserving the native turtles and is working to protect them through various efforts which include:
  • Feral animal control in and around turtle nesting sites in conjunction with the Department of Biodiversity, Conservation and Attractions
  • Protective and directional fencing to guide turtles into the nesting refuges
  • Upgrading turtle nesting cages along Bibra Lake foreshore
  • Installation of permanent/mobile turtle crossing warning signage surrounding Bibra Lake and speed check signage on Progressive Drive
  • Wildlife cameras installed around Bibra Lake to track turtle predators
  • GPS trackers installed on nesting females to help research movements
  • Turtle ecology research in partnership with Murdoch University
  • Turtle Trackers Citizen Science Program
Turtle Trackers – Citizen Science Program
‘Turtle Trackers’ Citizen Science Program and associated ‘Turtle Watch’ Educational Program are ongoing programs run by the City of Cockburn. These programs are dedicated to providing information about the turtles. They also encourage the community to participate in turtle watching and report sightings in support of scientific research.

Turtle Trackers is a partnership between Murdoch University, The Wetlands Centre Cockburn, WA Wildlife (formerly Native ARC), Department of Biodiversity, Conservation and Attractions (DBCA), Regional Park within DBCA and the City of Cockburn. This project aims to involve the community in its protection efforts. Turtle Tracker volunteers track nesting female turtles around Bibra Lake during peak nesting season (September to November), log information about turtle sightings and behaviour, and help install nesting cages to protect hatchlings.

During the 2018/19 nesting season, 135 nests were found predated around Bibra Lake. This was the catalyst for the Turtle Trackers program. In 2019, the Turtle Trackers program was created and volunteer Turtle Trackers conducted patrols on 44 different days during the peak nesting season. Nesting was observed on several of those days, and the Native ARC managed to protect these nests with specially installed nesting cages. Data on turtle behaviour and movement were also successfully recorded and contributed to scientific research. So far, it has shown that community involvement could be a key part of saving species that may not be adapting to urban environments.

To get involved, you can join the Turtle Watch program or volunteer as a Turtle Tracker for the 2020/21 nesting season by sending the Environmental Team an email.

Frequently Asked Questions

What should I do if I find a turtle?
Firstly, check which direct the turtle is heading towards. If it is heading towards land, it may be searching for a suitable nesting site. If it is heading towards a lake, it may be trying to migrate to water. Please check that there are no threats close by and leave the turtle alone as much as possible. You can monitor the turtle from a safe distance and protect it from potential threats such as birds. If a turtle is on the road, please escort it across without picking it up. If you catch and return a turtle to the water before it has nested, it will either abort its eggs or have to make the dangerous trip again. This increases its risk of being injured or killed.

Call your nearest Turtle Watch Helpline or go to the Climate Watch website and record your lucky sighting!
 
What should I do if I find an injured turtle?

Please make sure that the turtle is actually injured before you intervene. A turtle may be injured by a car or attacked by an animal in which case it won't be moving much. If the turtle appears lethargic and dehydrated it is probably injured. Contact WA Wildlife opens in a new window (formerly Native ARC) if you find a turtle in the City area. Turtles can make remarkable recoveries from serious injuries.

How do I handle a turtle if necessary?

Please only handle a turtle if you are instructed do so by a fauna management specialist.
If instructed to handle a turtle, grasp the turtle from behind with your hand between the back legs (palm over tail, thumb on top of shell and fingers underneath) and support the head with your other hand if necessary. Hold the animal away from your body. This way you avoid the hind legs that may cause minor scratches by their small claws. Holding the turtle away from your body will also avoid any bodily secretions from the turtle.

If instructed to handle a turtle, grasp the turtle around the middle of the carapace (upper shell) and hold the animal away from your body. This way you avoid the hind legs that may cause minor scratches by their small claws. Holding the turtle away from your body will also avoid any bodily secretions from the turtle.

Can I keep a turtle as a pet?
No. Catching and keeping turtles as pets is illegal and is also a threat to population numbers.
 
What’s the difference between a turtle and a tortoise?
A ‘turtle’ is water dwelling and a ‘tortoise’ is land dwelling. Turtles also have a flat shell with webbed feet and claws or flippers. Tortoises have a domed shell with short, sturdy bent legs.
 
 

More Information and Contact

Contact the City Environmental Department for further information on 08 9411 3444 or email
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Contact

Address

9 Coleville Crescent,
Spearwood 6163

PO Box 1215, Bibra Lake DC,
Western Australia, 6965

Language Support

Cockburn Nyungar moort Beeliar boodja-k kaadadjiny. Koora, yeyi, benang baalap nidja boodja-k kaaradjiny.
Ngalak kaadatj dayin boodja, kep wer malayin. Ngalak kaadatj koora koora wer yeyi ngalang birdiya.

City of Cockburn acknowledges the Nyungar people of Beeliar boodja. Long ago, now and in the future they care for country.
We acknowledge a continuing connection to land, waters and culture and pay our respects to the Elders, past, present and emerging.