Truii data visualisation, analysis and management Saltwater crocodile caught in the town reach of the Johnstone River Innisfail ca. 1903

Crocodiles in Queensland – where not to swim?

After a recent post on shark culling in Queensland and shark attacks Australia wide this post is about about Australia’s other aquatic apex predator – the saltwater crocodile. The Queensland government has a record of 25 saltwater crocodile attacks since 1985 (eight of them fatal).

Where are they?

The creeks and estuaries in north Queensland have seen a huge number of croc sightings (Figure 1) – best to swim in the pool if you are north of Bundaberg. The size and colour of the circles reflect the length of the crocodile (sightings without a length record are represented as small circles). Most of the reported sightings are around populated areas. Surprisingly there have been several reported sightings in the south east – even as far south as the Gold Coast. Presumably those sightings in central Queensland are freshwater crocodiles.

Figure 1: Crocodile observations in Qld – zoom in to some of the creeks and estuaries (Source

How big are they?

The dominant croc size is small (Figure 2) but there have been 1086 crocs over 2.8m sighted. Fourteen crocs over 5.6m in length have been spotted – that is a lot of croc.

Figure 2: Size of crocodiles sighted in Qld (Source

About the data

The Queensland government maintains a survey of crocodile sightings, and there is a public register of crocodile sightings – (Croc watch). While these data sets don’t represent a complete population survey of crocodile numbers, they do show where crocs have been spotted. The map showing where crocodiles have been sighted is a sobering reminder not to go swimming in the tropics (Figure 1).

The data from Figure 1 is from (attribution to Environment and Heritage Protection, Queensland Government) and covers the period from 2000-2016. I combined the government sightings and the Croc Watch sightings and removed any observations without a location recorded. I have simply set the length to zero for those sightings without a length recorded – so the small dots on the map don’t necessarily mean a small croc.

About the data visualisations

The data visualisations are contained within their own Dashboard. You can link to the Dashboard, or use the shortcode from the visualisations to embed them in another web page. This data is from, a wrangled version is available on Truii for your own analysis.

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