Research and initiatives

Crocodiles are shy, well-camouflaged and mobile, which makes them a challenge to study. We take advantage of our regular interaction with crocodiles to run a number of research projects. Knowing more about crocodiles helps us develop tools and strategies to make our work safer and more efficient and provide policymakers and the community with the most accurate information, helping protect Queenslanders from harm.

Crocodile Monitoring Project

This ongoing study consists of comprehensive vessel and helicopter surveys of north Queensland’s major river systems. It provides a snapshot of the number and biomass of Queensland’s crocodile population and allows us to compare it to previous studies, showing population changes over time. This information helps inform future policy and management actions.

Queensland Estuarine Crocodile Monitoring Program 2016–2019

From 2016 to 2019, the department conducted a comprehensive monitoring program of the estuarine crocodile population across its range in Queensland. During 2020, we compiled and analysed data collected through this program and compared these to historic data to assess how the population had changed in size, distribution, density, and size class structure over time–using results collected from as far back as 1979. Further information about this program is available in the key findings report (PDF, 991.2KB) and the comprehensive technical report.

Technical report:

Download the full version of the technical report:

Or browse sections of the report:

Detection and Deterrent Project

In world-first research, departmental wildlife officers are examining the way crocodiles communicate through sounds, with early investigations revealing a surprising complexity of vocalisations. The application of this new knowledge could lead to innovative techniques to attract or repel crocodiles.

The department is also exploring how using multi-beam sonar technology together with image recognition software can detect crocodiles in an area and alert authorities of their presence. Our aim is to deploy this technology using a clever buoy system, which also records other environmental data (temperature, wind, humidity), to determine when and why crocodiles move into areas frequented by people.

Movement and DNA Project

Decades of satellite tracking have given us a solid idea of how crocodiles use and move through river environments, but what about oceans? The department is currently exploring this new frontier of crocodile habitat use by attaching satellite trackers to animals in the Torres Strait.

Wildlife officers have also been collecting DNA samples from crocodiles and analysing them to determine the relatedness and connectivity of the population in Queensland. These two parts of the project work help paint a picture of crocodile movement in Queensland, and between other populations nearby. The information gathered may directly impact how we manage crocodiles into the future.

Crocodile genetics research report

The genetic structure and connectivity of the estuarine crocodile (Crocodylus porosus) in Queensland 2018–2020 study redefines what is known about estuarine crocodiles in Queensland and more broadly.

Based on over two decades of movement studies, it was believed that estuarine crocodiles could move everywhere and anywhere.

The results of this genetics study have redefined what is known about estuarine crocodiles in Queensland and the species more generally.

It provides an understanding about where crocodiles in Queensland are from (source), where they go (sink), and how far they travel.

This knowledge helps to inform more efficient and effective management and reduce the threat to public safety.

Key facts

  • The estuarine crocodile population within Queensland can be described as six sub-populations.
  • Most crocodiles remain close to their place of birth with 90% of crocodiles dispersing less than 50km, leading to localised populations.
  • There is evidence of historical and recent movement of crocodiles between adjacent sub-populations with connectivity declining with distance.

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  • In 2018, the Queensland Government began a long-term project to study the movements of Queensland’s saltwater (estuarine) crocodile population using DNA.

    In 2018, the Queensland Government began a long-term project to study the movements of Queensland’s saltwater (estuarine) crocodile population using DNA.

Population modelling dynamics study

Modelling population dynamics of estuarine crocodiles on Queensland’s northern populated east coast

In response to the Independent Crocodile Expert Committee's recommendation to consider removing additional larger crocodiles of more than 2.4 metres in length (recommendation 6), the department commissioned research to undertake further modelling work in relation to estuarine population numbers, specifically in the northern populated east coast (NPEC) region (between Cooktown and Ingham).

Dr Laurence Taplin’s report, Modelling population dynamics of estuarine crocodiles on Queensland’s northern populated east coast, assessed how removing different numbers and ages of crocodiles would impact on the total number of crocodiles in the NPEC area in the long-term.

The population modelling study found that:

  • the NPEC crocodile population is not at risk of extinction in the foreseeable future unless there is a significant change in crocodile management practices.
  • continuing the current rate of removal is likely to be a safe strategy from a species conservation standpoint and as an effective public safety management strategy.

The report’s insights and projections about the NPEC crocodile population and potential impacts on the crocodile populations will help inform options for future approaches to estuarine crocodile management.

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Heading to Tropical North Qld this winter?

Be Crocwise in Croc Country.
Learn more about how to stay safe around the water and reduce your risk.