Gelochelidon nilotica
Silhouette: Sheatherius · PhyloPic
In 3 days ~10% in a week ~30%
The gull-billed tern (Gelochelidon nilotica) is a tern in the family Laridae. It is widely distributed and breeds in scattered localities in Europe, Asia, northwest Africa, and the Americas. The Australian gull-billed tern was previously considered a subspecies.
The gull-billed tern was formally described in 1789 by the German naturalist Johann Friedrich Gmelin in his revised and expanded edition of Carl Linnaeus's Systema Naturae. He placed it with terns in the genus Sterna and coined the binomial name Sterna nilotica. Gmelin based his description on the "Egyptian tern" that had been described in 1785 by the English ornithologist John Latham in his book A General Synopsis of Birds. Latham had in turn based his own account on that by the Swedish naturalist Fredrik Hasselquist that was published in 1757. The gull-billed tern was moved to the resurrected genus Gelochelidon based on a molecular phylogenetic study published in 2005. The genus had been introduced in 1830 by the German zoologist Christian Ludwig Brehm. The genus name combines the Ancient Greek gelaō meaning "to laugh" with khelidōn meaning "swallow". The specific epithet nilotica is from Latin niloticus meaning... Wikipedia →
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Zanzibar City | 🇹🇿 Tanzania | |
| 2 | Karachi | 🇵🇰 Pakistan | |
| 3 | Kuwait City | 🇰🇼 Kuwait | |
| 4 | Manama | 🇧🇭 Bahrain | |
| 5 | São Luís | 🇧🇷 Brazil | |
| 6 | Dakar | 🇸🇳 Senegal | |
| 7 | Dar es-Salaam | 🇹🇿 Tanzania | |
| 8 | Barranquilla | 🇨🇴 Colombia | |
| 9 | Luxor | 🇪🇬 Egypt | |
| 10 | Mumbai | 🇮🇳 India |
| # | Zoo / Centre | Country | |
|---|---|---|---|
| 1 | Zoobotánico Jerez | 🇪🇸 Spain |
Rare
Under 5% of wildlife watchers report a Gull-billed Tern sighting in Celestún Biosphere Reserve on a given day, based on 73 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 148th most-seen of the 297 birds we can rate there. Over three days the chance rises to about 10%, and over a week to about 30%, if each day is a fresh chance.
July–August and October–December
In those months about 10% of wildlife watchers report a Gull-billed Tern in Celestún Biosphere Reserve on a given day, against under 5% in January–June and September, the lowest months.
Between 9 am and noon
Across all the parks we cover, that three-hour window holds the most Gull-billed Tern sightings with a recorded time, and about 9 in 10 of them come between 6 am and 6 pm: it is a daytime animal.
20th of 45
Of the 45 parks where we can rate Gull-billed Tern sightings, Celestún Biosphere Reserve ranks 20th at under 5%. The best odds are in Lake Nakuru National Park (Kenya, about 40%), Ngorongoro Conservation Area (Tanzania, about 30%) and Yala National Park (Sri Lanka, about 30%). All parks ranked.
Same family: Laridae
The closest relatives of the Gull-billed Tern that you can see in Celestún Biosphere Reserve (family Laridae, Gulls, Terns, and Skimmers) are Laughing Gull (about 70%), Sandwich Tern (about 40%) and Royal Tern (about 40%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Gull-billed Tern is recorded against all the birds logged in Celestún Biosphere Reserve (73 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.
