Varanus tristis
Silhouette: Steven Traver · PhyloPic
In 3 days ~50% in a week ~80%
The black-headed monitor or black-tailed monitor (Varanus tristis) is a relatively small species of monitor lizards native to Australia. It is occasionally also called the mournful monitor, freckled monitor (Varanus tristis orientalis) or the racehorse monitor, a name it shares with the Gould's monitor due to their exceptional speed. It is placed in the subgenus Odatria.
Its specific name, tristis, means "sad", in reference to the completely black colouration of V. t. tristis populations around Perth. This is the most widespread monitor species in Australia, occurring throughout the mainland and even on some northern islands such as Magnetic Island. The two subspecies are sympatric in some areas such as the east coast of Queensland. This arboreal monitor lizard is usually found near rivers in forests, scrublands, woodlands, but also inhabits deserts. It takes shelter in tight spaces such as loose bark, tree hollows, and rocky crevices. Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Uluru-Kata Tjuta National Park | 🇦🇺 Australia | |
| 2 | Kakadu National Park | 🇦🇺 Australia |
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Perth | 🇦🇺 Australia |
| # | Zoo / Centre | Country | |
|---|---|---|---|
| 1 | National Zoo & Aquarium | 🇦🇺 Australia | |
| 2 | Fort Wayne Children's Zoo | 🇺🇸 United States |
Possible
About 20% of wildlife watchers report a Black-headed Monitor sighting in Kakadu National Park on a given day, based on 15 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 24th most-seen of the 54 reptiles we can rate there. Over three days the chance rises to about 50%, and over a week to about 80%, if each day is a fresh chance.
January
In that month about 50% of wildlife watchers report a Black-headed Monitor in Kakadu National Park on a given day, against under 5% in February–April, September–October and December, the lowest months. That is one of Kakadu National Park's wettest months, with about 350 mm of rain against almost none in August.
Between 1 and 4 pm
Across all the parks we cover, that three-hour window holds the most Black-headed Monitor sightings with a recorded time, and about 9 in 10 of them come between 6 am and 6 pm: it is a daytime animal.
Among the best
Of the 2 parks where we can rate Black-headed Monitor sightings, Kakadu National Park ranks 2nd at about 20%, level with the leaders once rounded. The best odds are in Uluru-Kata Tjuta National Park (Australia, about 20%).
Same genus: Varanus
The closest relatives of the Black-headed Monitor that you can see in Kakadu National Park (genus Varanus, Monitor Lizards) are Argus Monitor (about 30%), Mertens's Water Monitor (about 30%) and Gould's Goanna (about 20%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Black-headed Monitor is recorded against all the reptiles logged in Kakadu National Park (15 verified sightings from 2019 to 2026), calibrated against known sighting rates. Figures are rounded to the nearest 10% because citizen-science data supports honest approximations, not decimals, and months with records from fewer than five people show "—". How it works.
