Creagrus furcatus
Silhouette: Sue Cantan (photograph) and T. Michael Keesey (vectorization) · PhyloPic
In 3 days <5%
The swallow-tailed gull (Creagrus furcatus) is an equatorial seabird in the gull family, Laridae. It is the only species in the genus Creagrus, which derives from the Latin Creagra and the Greek kreourgos which means butcher, also from kreas, meat; according to Jobling it would mean "hook for meat" referring to the hooked bill of this species. It was first described by French naturalist and surgeon Adolphe-Simon Neboux in 1846. Its scientific name is originally derived from the Greek word for gull, "Glaros" and via Latin Larus, "gull" and furca "two-tined fork". It spends most of its life flying and hunting over the open ocean. The main breeding location is in the Galápagos Islands, particularly the rocky shores and cliffs of Hood, Tower and Wolf Islands, with lower numbers on most of the other islands. It is more common on the eastern islands where the water is warmer.
It is the only fully nocturnal gull and seabird in the world, preying on squid and small fish which rise to the surface at night to feed on plankton. The swallow-tailed gull has no structural or plumage differences between the male and female. In the breeding season, the adult has a black plumaged... Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Galápagos Islands | 🇪🇨 Ecuador |
More parks will be added in future updates.
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Lima | 🇵🇪 Peru |
Rare
Under 5% of wildlife watchers report a Swallow-tailed Gull sighting in Lima on a given day, based on 15 verified sightings from GBIF citizen-science data. It is the 160th most-seen of the 171 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 Swallow-tailed Gull in Lima on a given day, so our monthly data shows no clear season.
Between 3 and 6 pm
Across all the parks we cover, that three-hour window holds the most Swallow-tailed 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.
Only Lima, in our data
Lima is the only city on Wallace's Line with enough records to rate Swallow-tailed Gull sightings: under 5% of wildlife watchers there report one on a given day.
Same family: Laridae
The closest relatives of the Swallow-tailed Gull that you can see in Lima (family Laridae, Gulls, Terns, and Skimmers) are Dominican Gull (about 30%), Belcher's Gull (about 30%) and Franklin's Gull (about 30%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Swallow-tailed Gull is recorded against all the birds logged in Lima (15 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.
