Gelochelidon macrotarsa
In 3 days ~30% in a week ~50%
The Australian tern or Australian gull-billed tern (Gelochelidon macrotarsa) is a tern in the family Laridae, native to Australia. The genus name is from Ancient Greek gelao, "to laugh", and khelidon, "swallow". John Gould described Sterna macrotarsa from a specimen held at King's College, London in 1837. Although first described as a species, throughout most of the 20th and early 21st centuries it was generally considered to be a subspecies of the gull-billed tern, but was re-elevated to species status by the IOC World Bird List in 2019 in its Version 9.2.
This is a fairly large and powerful tern, similar in size and general appearance to a Sandwich tern, but the short thick gull-like bill, broad wings, long legs and robust body are distinctive. The summer adult has pale grey upperparts, white underparts, a black cap, strong black bill and black legs. The call is a characteristic ker-wik. It is 33–42 cm (13–17 in) in length and 76–91 cm (30–36 in) in wingspan. Its weight ranges from 150–292 g (5.3–10.3 oz). It differs from the closely related gull-billed tern in being slightly larger, paler grey above, and with an obviously larger, heavier bill.
In... Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Cape Range | 🇦🇺 Australia | |
| 2 | Ningaloo Marine Park | 🇦🇺 Australia | |
| 3 | Noosa National Park | 🇦🇺 Australia | |
| 4 | Kakadu National Park | 🇦🇺 Australia | |
| 5 | Daintree National Park | 🇦🇺 Australia |
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Brisbane | 🇦🇺 Australia |
With luck
About 10% of wildlife watchers report an Australian Tern sighting in Ningaloo Marine Park on a given day, based on 28 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 52nd most-seen of the 102 birds we can rate there. Over three days the chance rises to about 30%, and over a week to about 50%, if each day is a fresh chance.
April
In that month about 20% of wildlife watchers report an Australian Tern in Ningaloo Marine Park on a given day, against under 5% in March and May, the lowest months.
Between noon and 3 pm
Across all the parks we cover, that three-hour window holds the most Australian Tern sightings with a recorded time, and nearly all of them come between 6 am and 6 pm: it is a daytime animal.
Among the best
Of the 5 parks where we can rate Australian Tern sightings, Ningaloo Marine Park ranks 2nd at about 10%, level with the leaders once rounded. The best odds are in Cape Range (Australia, about 10%).
Same family: Laridae
The closest relatives of the Australian Tern that you can see in Ningaloo Marine Park (family Laridae, Gulls, Terns, and Skimmers) are Silver Gull (about 80%), Crested Tern (about 50%) and Caspian Tern (about 30%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Australian Tern is recorded against all the birds logged in Ningaloo Marine Park (28 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.
