Chroicocephalus genei
Silhouette: Michael Scroggie · PhyloPic
In 3 days ~50% in a week ~80%
The slender-billed gull (Chroicocephalus genei) is a mid-sized gull which breeds very locally around the Mediterranean and the north of the western Indian Ocean (e.g. Pakistan) on islands and coastal lagoons. Most of the population is somewhat migratory, wintering further south to as far as North Africa and India. A few birds have wandered to western Europe. A vagrant individual was reportedly seen on Antigua, April 24, 1976 (AOU, 2000).
The genus name Chroicocephalus is from Ancient Greek khroizo, "to colour", and kephale, "head". The specific genei commemorates Italian naturalist Giuseppe Gené. This species is 37 to 40 cm (14.6 to 15.7 in) long with a 90 to 102 cm (35.4 to 40.2 in) wingspan. It is therefore slightly larger than the black-headed gull, which it resembles, although it does not have a black hood in summer. It has a pale grey body, white head and breast and black tips to the primary wing feathers. The head and dark red bill have an elongated tapering appearance, and this bird also appears long-necked. The legs are dark red, and the iris is yellow. In summer, the breast has a faint pink colouration. This bird takes two years to reach maturity, as is...
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Saloum Delta National Park | 🇸🇳 Senegal | |
| 2 | Djoudj National Bird Sanctuary | 🇸🇳 Senegal | |
| 3 | Camargue | 🇫🇷 France | |
| 4 | Doñana National Park | 🇪🇸 Spain | |
| 5 | Murchison Falls National Park | 🇺🇬 Uganda | |
| 6 | Lake Nakuru National Park | 🇰🇪 Kenya |
Possible
About 20% of wildlife watchers report a Slender-billed Gull sighting in Djoudj National Bird Sanctuary on a given day, based on 26 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 113th most-seen of the 173 birds we can rate there. Over three days the chance rises to about 50%, and over a week to about 80%, if each day is a fresh chance.
January
In that month about 30% of wildlife watchers report a Slender-billed Gull in Djoudj National Bird Sanctuary on a given day, against about 10% in February and December, the lowest months. That is one of Djoudj National Bird Sanctuary's driest months, with almost no rain against 55 mm in August. May to October have too few records to rate.
Between 8 and 11 am
Across all the parks we cover, that three-hour window holds the most Slender-billed Gull sightings with a recorded time, and about 8 in 10 of them come between 6 am and 6 pm: it is a daytime animal.
2nd of 6
Of the 6 parks where we can rate Slender-billed Gull sightings, Djoudj National Bird Sanctuary ranks 2nd at about 20%. The best odds are in Saloum Delta National Park (Senegal, about 50%). All parks ranked.
Same genus: Chroicocephalus
The closest relatives of the Slender-billed Gull that you can see in Djoudj National Bird Sanctuary (genus Chroicocephalus, Masked Gulls and allies) are Black-headed Gull (about 20%) and Grey-hooded Gull (about 10%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Slender-billed Gull is recorded against all the birds logged in Djoudj National Bird Sanctuary (26 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.
