Onychoprion fuscatus
Silhouette: Sheatherius · PhyloPic
In 3 days <5%
The sooty tern (Onychoprion fuscatus) is a tern in the family Laridae. It is a seabird of the tropical oceans and can fly for years at a time, skimming the sea surface for food, and returning to land only to breed, on islands throughout the equatorial zone.
The sooty tern was described by Carl Linnaeus in 1766 as Sterna fuscata, bearing this name for many years until the genus Sterna was split up; it is now classified in the genus Onychoprion as Onychoprion fuscatus. The genus name is from ancient Greek onux, "claw" or "nail", and prion, "saw". The species name fuscatus is Latin for "dark".
The sooty tern has little interspecific variation, but it is usually divided into six to eight allopatric subspecies. Some recent authors further subdivide the Indopacific population into up to eight subspecies altogether, but much of the variation is clinal. The affinities of eastern Pacific birds (including O. f. manutarus of Easter Island) are most strongly contested. Six subspecies are currently accepted by the IOC:
Onychoprion fuscatus fuscatus (Linnaeus, 1766) – breeds on tropical Atlantic Ocean, Gulf of Mexico, and Caribbean islands. Underparts white. Onychoprion fuscatus nubilosus... Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Raja Ampat | 🇮🇩 Indonesia | |
| 2 | Galápagos Islands | 🇪🇨 Ecuador | |
| 3 | Everglades National Park | 🇺🇸 United States |
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Auckland | 🇳🇿 New Zealand | |
| 2 | Mumbai | 🇮🇳 India | |
| 3 | Colombo [Sri Jayawardenepura Kotte] | 🇱🇰 Sri Lanka | |
| 4 | Miami | 🇺🇸 United States |
Rare
Under 5% of wildlife watchers report a Sooty Tern sighting in Mumbai on a given day, based on 21 verified sightings from GBIF citizen-science data. It is the 243rd most-seen of the 283 birds we can rate there. Over three days the chance rises to under 5%, if each day is a fresh chance.
Any time of year
In every month with enough records, under 5% of wildlife watchers report a Sooty Tern in Mumbai on a given day, so our monthly data shows no clear season.
Between 7 and 10 am
Across all the parks we cover, that three-hour window holds the most Sooty 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.
2nd of 4
Of the 4 cities where we can rate Sooty Tern sightings, Mumbai ranks 2nd at under 5%. The best odds are in Auckland (New Zealand, about 10%).
GBIF citizen-science records
It is estimated from how often the Sooty Tern is recorded against all the birds logged in Mumbai (21 verified sightings), 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.
