Chroicocephalus bulleri
Silhouette: Michael Scroggie · PhyloPic
In 3 days ~10% in a week ~20%
The black-billed gull (Chroicocephalus bulleri), also called Buller's gull or tarāpuka (Māori), is a Near Threatened species of gull in the family Laridae. This gull is found only in New Zealand, its ancestors having arrived from Australia around 250,000 years ago.
Originally named Gavia pomare in 1855 by Carl Friedrich Bruch, the name was rejected by the New Zealand ornithologist Sir Walter Lawry Buller because it was already being used for another species. He then took up Prince Napoléon Bonaparte's "playful" genus name Bruchigavia (literally, "Bruch's seabird") as a provisional name for New Zealand gulls. But because Buller's proposed species name melanoryncha (literally, "black-billed") had already been given to another gull species, Frederick Hutton suggested the name bulleri, in honor of Buller, in 1871. Buller accepted the offer and followed others in adopting the "larger and better-defined genus" of Larus. The alternative common name Buller's gull also retains the connection to Buller.
The species is now considered to belong within the genus Chroicocephalus. The holotype is in the collection of the Museum of New Zealand Te Papa Tongarewa. A... Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Fiordland National Park | 🇳🇿 New Zealand | |
| 2 | Abel Tasman National Park | 🇳🇿 New Zealand | |
| 3 | Aoraki Mount Cook National Park | 🇳🇿 New Zealand | |
| 4 | Rakiura National Park | 🇳🇿 New Zealand | |
| 5 | Arthur's Pass National Park | 🇳🇿 New Zealand |
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Auckland | 🇳🇿 New Zealand |
Rare
Under 5% of wildlife watchers report a Black-billed Gull sighting in Rakiura National Park on a given day, based on 52 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 58th most-seen of the 80 birds we can rate there. Over three days the chance rises to about 10%, and over a week to about 20%, if each day is a fresh chance.
March, June and August
In those months about 10% of wildlife watchers report a Black-billed Gull in Rakiura National Park on a given day, against under 5% in April–May, July and September–February, the lowest months.
Between 1 and 4 pm
Across all the parks we cover, that three-hour window holds the most Black-billed Gull sightings with a recorded time, and about 9 in 10 of them come between 6 am and 6 pm: it is a daytime animal.
4th of 5
Of the 5 parks where we can rate Black-billed Gull sightings, Rakiura National Park ranks 4th at under 5%. The best odds are in Fiordland National Park (New Zealand, about 40%), Abel Tasman National Park (New Zealand, about 10%) and Aoraki Mount Cook National Park (New Zealand, about 10%).
GBIF citizen-science records
It is estimated from how often the Black-billed Gull is recorded against all the birds logged in Rakiura National Park (52 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.
